isl_input.c

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/*
 * Copyright 2008-2009 Katholieke Universiteit Leuven
 * Copyright 2010      INRIA Saclay
 * Copyright 2012-2013 Ecole Normale Superieure
 * Copyright 2019,2022 Cerebras Systems
 *
 * Use of this software is governed by the MIT license
 *
 * Written by Sven Verdoolaege, K.U.Leuven, Departement
 * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
 * and INRIA Saclay - Ile-de-France, Parc Club Orsay Universite,
 * ZAC des vignes, 4 rue Jacques Monod, 91893 Orsay, France 
 * and Ecole Normale Superieure, 45 rue d’Ulm, 75230 Paris, France
 * and Cerebras Systems, 175 S San Antonio Rd, Los Altos, CA, USA
 */
 
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <isl_ctx_private.h>
#include <isl_map_private.h>
#include <isl_id_private.h>
#include <isl/set.h>
#include <isl_seq.h>
#include <isl_stream_private.h>
#include <isl/obj.h>
#include "isl_polynomial_private.h"
#include <isl/union_set.h>
#include <isl/union_map.h>
#include <isl_mat_private.h>
#include <isl_aff_private.h>
#include <isl_vec_private.h>
#include <isl/list.h>
#include <isl_val_private.h>
 
struct variable {
  char            *name;
  int          pos;
  struct variable   *next;
};
 
struct vars {
  struct isl_ctx *ctx;
  int    n;
  struct variable *v;
};
 
static struct vars *vars_new(struct isl_ctx *ctx)
{
  struct vars *v;
  v = isl_alloc_type(ctx, struct vars);
  if (!v)
    return NULL;
  v->ctx = ctx;
  v->n = 0;
  v->v = NULL;
  return v;
}
 
static void variable_free(struct variable *var)
{
  while (var) {
    struct variable *next = var->next;
    free(var->name);
    free(var);
    var = next;
  }
}
 
static void vars_free(struct vars *v)
{
  if (!v)
    return;
  variable_free(v->v);
  free(v);
}
 
static void vars_drop(struct vars *v, int n)
{
  struct variable *var;
 
  if (!v || !v->v)
    return;
 
  v->n -= n;
 
  var = v->v;
  while (--n >= 0) {
    struct variable *next = var->next;
    free(var->name);
    free(var);
    var = next;
  }
  v->v = var;
}
 
static struct variable *variable_new(struct vars *v, const char *name, int len,
        int pos)
{
  struct variable *var;
  var = isl_calloc_type(v->ctx, struct variable);
  if (!var)
    goto error;
  var->name = strdup(name);
  var->name[len] = '\0';
  var->pos = pos;
  var->next = v->v;
  return var;
error:
  variable_free(v->v);
  return NULL;
}
 
static int vars_pos(struct vars *v, const char *s, int len)
{
  int pos;
  struct variable *q;
 
  if (len == -1)
    len = strlen(s);
  for (q = v->v; q; q = q->next) {
    if (strncmp(q->name, s, len) == 0 && q->name[len] == '\0')
      break;
  }
  if (q)
    pos = q->pos;
  else {
    pos = v->n;
    v->v = variable_new(v, s, len, v->n);
    if (!v->v)
      return -1;
    v->n++;
  }
  return pos;
}
 
static int vars_add_anon(struct vars *v)
{
  v->v = variable_new(v, "", 0, v->n);
 
  if (!v->v)
    return -1;
  v->n++;
 
  return 0;
}
 
/* Obtain next token, with some preprocessing.
 * In particular, evaluate expressions of the form x^y,
 * with x and y values.
 */
static struct isl_token *next_token(__isl_keep isl_stream *s)
{
  struct isl_token *tok, *tok2;
 
  tok = isl_stream_next_token(s);
  if (!tok || tok->type != ISL_TOKEN_VALUE)
    return tok;
  if (!isl_stream_eat_if_available(s, '^'))
    return tok;
  tok2 = isl_stream_next_token(s);
  if (!tok2 || tok2->type != ISL_TOKEN_VALUE) {
    isl_stream_error(s, tok2, "expecting constant value");
    goto error;
  }
 
  isl_int_pow_ui(tok->u.v, tok->u.v, isl_int_get_ui(tok2->u.v));
 
  isl_token_free(tok2);
  return tok;
error:
  isl_token_free(tok);
  isl_token_free(tok2);
  return NULL;
}
 
/* Read an isl_val from "s".
 *
 * The following token sequences are recognized
 *
 *  "infty"   ->  infty
 *  "-" "infty" ->  -infty
 *  "NaN"   ->  NaN
 *  n "/" d   ->  n/d
 *  "-" n "/" d ->  -n/d
 *  v   ->  v
 *  "-" v   ->  -v
 *
 * where n, d and v are integer constants.
 */
__isl_give isl_val *isl_stream_read_val(__isl_keep isl_stream *s)
{
  struct isl_token *tok = NULL;
  struct isl_token *tok2 = NULL;
  int sign = 1;
  isl_val *val;
 
  if (isl_stream_eat_if_available(s, '-'))
    sign = -1;
  tok = next_token(s);
  if (!tok) {
    isl_stream_error(s, NULL, "unexpected EOF");
    goto error;
  }
  if (tok->type == ISL_TOKEN_INFTY) {
    isl_token_free(tok);
    if (sign > 0)
      return isl_val_infty(s->ctx);
    else
      return isl_val_neginfty(s->ctx);
  }
  if (sign > 0 && tok->type == ISL_TOKEN_NAN) {
    isl_token_free(tok);
    return isl_val_nan(s->ctx);
  }
  if (tok->type != ISL_TOKEN_VALUE) {
    isl_stream_error(s, tok, "expecting value");
    goto error;
  }
 
  if (sign < 0)
    isl_int_neg(tok->u.v, tok->u.v);
 
  if (isl_stream_eat_if_available(s, '/')) {
    tok2 = next_token(s);
    if (!tok2) {
      isl_stream_error(s, NULL, "unexpected EOF");
      goto error;
    }
    if (tok2->type != ISL_TOKEN_VALUE) {
      isl_stream_error(s, tok2, "expecting value");
      goto error;
    }
    val = isl_val_rat_from_isl_int(s->ctx, tok->u.v, tok2->u.v);
    val = isl_val_normalize(val);
  } else {
    val = isl_val_int_from_isl_int(s->ctx, tok->u.v);
  }
 
  isl_token_free(tok);
  isl_token_free(tok2);
  return val;
error:
  isl_token_free(tok);
  isl_token_free(tok2);
  return NULL;
}
 
#undef TYPE_BASE
#define TYPE_BASE val
#include "isl_read_from_str_templ.c"
 
static isl_stat accept_cst_factor(__isl_keep isl_stream *s, isl_int *f)
{
  struct isl_token *tok;
 
  if (isl_stream_eat_if_available(s, '-'))
    isl_int_neg(*f, *f);
  tok = next_token(s);
  if (!tok || tok->type != ISL_TOKEN_VALUE) {
    isl_stream_error(s, tok, "expecting constant value");
    goto error;
  }
 
  isl_int_mul(*f, *f, tok->u.v);
 
  isl_token_free(tok);
 
  if (isl_stream_eat_if_available(s, '*'))
    return accept_cst_factor(s, f);
 
  return isl_stat_ok;
error:
  isl_token_free(tok);
  return isl_stat_error;
}
 
/* Given an affine expression aff, return an affine expression
 * for aff % d, with d the next token on the stream, which is
 * assumed to be a constant.
 *
 * We introduce an integer division q = [aff/d] and the result
 * is set to aff - d q.
 */
static __isl_give isl_pw_aff *affine_mod(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_pw_aff *aff)
{
  struct isl_token *tok;
  isl_pw_aff *q;
 
  tok = next_token(s);
  if (!tok || tok->type != ISL_TOKEN_VALUE) {
    isl_stream_error(s, tok, "expecting constant value");
    goto error;
  }
 
  q = isl_pw_aff_copy(aff);
  q = isl_pw_aff_scale_down(q, tok->u.v);
  q = isl_pw_aff_floor(q);
  q = isl_pw_aff_scale(q, tok->u.v);
 
  aff = isl_pw_aff_sub(aff, q);
 
  isl_token_free(tok);
  return aff;
error:
  isl_pw_aff_free(aff);
  isl_token_free(tok);
  return NULL;
}
 
static __isl_give isl_pw_aff *accept_affine(__isl_keep isl_stream *s,
  __isl_take isl_space *space, struct vars *v);
static __isl_give isl_pw_aff_list *accept_affine_list(__isl_keep isl_stream *s,
  __isl_take isl_space *space, struct vars *v);
 
static __isl_give isl_pw_aff *accept_minmax(__isl_keep isl_stream *s,
  __isl_take isl_space *space, struct vars *v)
{
  struct isl_token *tok;
  isl_pw_aff_list *list = NULL;
  int min;
 
  tok = isl_stream_next_token(s);
  if (!tok)
    goto error;
  min = tok->type == ISL_TOKEN_MIN;
  isl_token_free(tok);
 
  if (isl_stream_eat(s, '('))
    goto error;
 
  list = accept_affine_list(s, isl_space_copy(space), v);
  if (!list)
    goto error;
 
  if (isl_stream_eat(s, ')'))
    goto error;
 
  isl_space_free(space);
  return min ? isl_pw_aff_list_min(list) : isl_pw_aff_list_max(list);
error:
  isl_space_free(space);
  isl_pw_aff_list_free(list);
  return NULL;
}
 
/* Divide "pa" by an integer constant read from the stream.
 */
static __isl_give isl_pw_aff *pw_aff_div_by_cst(__isl_keep isl_stream *s,
  __isl_take isl_pw_aff *pa)
{
  struct isl_token *tok;
 
  tok = next_token(s);
  if (!tok || tok->type != ISL_TOKEN_VALUE) {
    isl_stream_error(s, tok, "expecting denominator");
    isl_token_free(tok);
    return isl_pw_aff_free(pa);
  }
 
  pa = isl_pw_aff_scale_down(pa,  tok->u.v);
 
  isl_token_free(tok);
 
  return pa;
}
 
/* Return the (signed) value that is next on the stream,
 * using "next" to read the next token and printing "msg" in case of an error.
 */
static struct isl_token *next_signed_value_fn(__isl_keep isl_stream *s,
  struct isl_token *(*next)(__isl_keep isl_stream *s), char *msg)
{
  struct isl_token *tok;
  int sign = 1;
 
  if (isl_stream_eat_if_available(s, '-'))
    sign = -1;
  tok = next(s);
  if (!tok || tok->type != ISL_TOKEN_VALUE) {
    isl_stream_error(s, tok, msg);
    isl_token_free(tok);
    return NULL;
  }
  if (sign < 0)
    isl_int_neg(tok->u.v, tok->u.v);
  return tok;
}
 
/* Return the (signed) value that is next on the stream,
 * printing "msg" in case of an error.
 */
static struct isl_token *next_signed_value(__isl_keep isl_stream *s, char *msg)
{
  return next_signed_value_fn(s, &isl_stream_next_token, msg);
}
 
/* Return the (signed) value that is next on the stream,
 * provided it is on the same line,
 * printing "msg" in case of an error.
 */
static struct isl_token *next_signed_value_on_same_line(
  __isl_keep isl_stream *s, char *msg)
{
  return next_signed_value_fn(s,
            &isl_stream_next_token_on_same_line, msg);
}
 
/* Is "tok" the start of an integer division?
 */
static int is_start_of_div(struct isl_token *tok)
{
  if (!tok)
    return 0;
  if (tok->type == '[')
    return 1;
  if (tok->type == ISL_TOKEN_FLOOR)
    return 1;
  if (tok->type == ISL_TOKEN_CEIL)
    return 1;
  if (tok->type == ISL_TOKEN_FLOORD)
    return 1;
  if (tok->type == ISL_TOKEN_CEILD)
    return 1;
  return 0;
}
 
/* Read an integer division from "s" and return it as an isl_pw_aff.
 *
 * The integer division can be of the form
 *
 *  [<affine expression>]
 *  floor(<affine expression>)
 *  ceil(<affine expression>)
 *  floord(<affine expression>,<denominator>)
 *  ceild(<affine expression>,<denominator>)
 */
static __isl_give isl_pw_aff *accept_div(__isl_keep isl_stream *s,
  __isl_take isl_space *space, struct vars *v)
{
  int f = 0;
  int c = 0;
  int extra = 0;
  isl_pw_aff *pwaff = NULL;
 
  if (isl_stream_eat_if_available(s, ISL_TOKEN_FLOORD))
    extra = f = 1;
  else if (isl_stream_eat_if_available(s, ISL_TOKEN_CEILD))
    extra = c = 1;
  else if (isl_stream_eat_if_available(s, ISL_TOKEN_FLOOR))
    f = 1;
  else if (isl_stream_eat_if_available(s, ISL_TOKEN_CEIL))
    c = 1;
  if (f || c) {
    if (isl_stream_eat(s, '('))
      goto error;
  } else {
    if (isl_stream_eat(s, '['))
      goto error;
  }
 
  pwaff = accept_affine(s, isl_space_copy(space), v);
 
  if (extra) {
    if (isl_stream_eat(s, ','))
      goto error;
 
    pwaff = pw_aff_div_by_cst(s, pwaff);
  }
 
  if (c)
    pwaff = isl_pw_aff_ceil(pwaff);
  else
    pwaff = isl_pw_aff_floor(pwaff);
 
  if (f || c) {
    if (isl_stream_eat(s, ')'))
      goto error;
  } else {
    if (isl_stream_eat(s, ']'))
      goto error;
  }
 
  isl_space_free(space);
  return pwaff;
error:
  isl_space_free(space);
  isl_pw_aff_free(pwaff);
  return NULL;
}
 
static __isl_give isl_pw_aff *accept_affine_factor(__isl_keep isl_stream *s,
  __isl_take isl_space *space, struct vars *v)
{
  struct isl_token *tok = NULL;
  isl_pw_aff *res = NULL;
 
  tok = next_token(s);
  if (!tok) {
    isl_stream_error(s, NULL, "unexpected EOF");
    goto error;
  }
 
  if (tok->type == ISL_TOKEN_AFF) {
    res = isl_pw_aff_copy(tok->u.pwaff);
    isl_token_free(tok);
  } else if (tok->type == ISL_TOKEN_IDENT) {
    int n = v->n;
    int pos = vars_pos(v, tok->u.s, -1);
    isl_aff *aff;
 
    if (pos < 0)
      goto error;
    if (pos >= n) {
      vars_drop(v, v->n - n);
      isl_stream_error(s, tok, "unknown identifier");
      goto error;
    }
 
    aff = isl_aff_zero_on_domain(isl_local_space_from_space(isl_space_copy(space)));
    if (!aff)
      goto error;
    aff->v = isl_vec_set_element_si(aff->v, 2 + pos, 1);
    if (!aff->v)
      aff = isl_aff_free(aff);
    res = isl_pw_aff_from_aff(aff);
    isl_token_free(tok);
  } else if (tok->type == ISL_TOKEN_VALUE) {
    if (isl_stream_eat_if_available(s, '*') ||
        isl_stream_next_token_is(s, ISL_TOKEN_IDENT)) {
      if (isl_stream_eat_if_available(s, '-'))
        isl_int_neg(tok->u.v, tok->u.v);
      res = accept_affine_factor(s, isl_space_copy(space), v);
      res = isl_pw_aff_scale(res, tok->u.v);
    } else {
      isl_local_space *ls;
      isl_aff *aff;
      ls = isl_local_space_from_space(isl_space_copy(space));
      aff = isl_aff_zero_on_domain(ls);
      aff = isl_aff_add_constant(aff, tok->u.v);
      res = isl_pw_aff_from_aff(aff);
    }
    isl_token_free(tok);
  } else if (tok->type == '(') {
    isl_token_free(tok);
    tok = NULL;
    res = accept_affine(s, isl_space_copy(space), v);
    if (!res)
      goto error;
    if (isl_stream_eat(s, ')'))
      goto error;
  } else if (is_start_of_div(tok)) {
    isl_stream_push_token(s, tok);
    tok = NULL;
    res = accept_div(s, isl_space_copy(space), v);
  } else if (tok->type == ISL_TOKEN_MIN || tok->type == ISL_TOKEN_MAX) {
    isl_stream_push_token(s, tok);
    tok = NULL;
    res = accept_minmax(s, isl_space_copy(space), v);
  } else {
    isl_stream_error(s, tok, "expecting factor");
    goto error;
  }
  if (isl_stream_eat_if_available(s, '%') ||
      isl_stream_eat_if_available(s, ISL_TOKEN_MOD)) {
    isl_space_free(space);
    return affine_mod(s, v, res);
  }
  if (isl_stream_eat_if_available(s, '*')) {
    isl_int f;
    isl_int_init(f);
    isl_int_set_si(f, 1);
    if (accept_cst_factor(s, &f) < 0) {
      isl_int_clear(f);
      goto error2;
    }
    res = isl_pw_aff_scale(res, f);
    isl_int_clear(f);
  }
  if (isl_stream_eat_if_available(s, '/'))
    res = pw_aff_div_by_cst(s, res);
  if (isl_stream_eat_if_available(s, ISL_TOKEN_INT_DIV))
    res = isl_pw_aff_floor(pw_aff_div_by_cst(s, res));
 
  isl_space_free(space);
  return res;
error:
  isl_token_free(tok);
error2:
  isl_pw_aff_free(res);
  isl_space_free(space);
  return NULL;
}
 
/* Return a piecewise affine expression defined on the specified domain
 * that represents NaN.
 */
static __isl_give isl_pw_aff *nan_on_domain(__isl_keep isl_space *space)
{
  return isl_pw_aff_nan_on_domain_space(isl_space_copy(space));
}
 
static __isl_give isl_pw_aff *accept_affine(__isl_keep isl_stream *s,
  __isl_take isl_space *space, struct vars *v)
{
  struct isl_token *tok = NULL;
  isl_local_space *ls;
  isl_pw_aff *res;
  int op = 1;
  int sign = 1;
 
  ls = isl_local_space_from_space(isl_space_copy(space));
  res = isl_pw_aff_from_aff(isl_aff_zero_on_domain(ls));
  if (!res)
    goto error;
 
  for (;;) {
    tok = next_token(s);
    if (!tok) {
      isl_stream_error(s, NULL, "unexpected EOF");
      goto error;
    }
    if (tok->type == '-') {
      sign = -sign;
      isl_token_free(tok);
      continue;
    }
    if (tok->type == '(' || is_start_of_div(tok) ||
        tok->type == ISL_TOKEN_MIN || tok->type == ISL_TOKEN_MAX ||
        tok->type == ISL_TOKEN_IDENT ||
        tok->type == ISL_TOKEN_VALUE ||
        tok->type == ISL_TOKEN_AFF) {
      isl_pw_aff *term;
      if (tok->type == ISL_TOKEN_VALUE && sign < 0) {
        isl_int_neg(tok->u.v, tok->u.v);
        sign = 1;
      }
      isl_stream_push_token(s, tok);
      tok = NULL;
      term = accept_affine_factor(s,
                isl_space_copy(space), v);
      if (op * sign < 0)
        res = isl_pw_aff_sub(res, term);
      else
        res = isl_pw_aff_add(res, term);
      if (!res)
        goto error;
    } else if (tok->type == ISL_TOKEN_NAN) {
      res = isl_pw_aff_add(res, nan_on_domain(space));
    } else {
      isl_stream_error(s, tok, "unexpected isl_token");
      isl_stream_push_token(s, tok);
      isl_pw_aff_free(res);
      isl_space_free(space);
      return NULL;
    }
    isl_token_free(tok);
 
    tok = next_token(s);
    sign = 1;
    if (tok && tok->type == '-') {
      op = -1;
      isl_token_free(tok);
    } else if (tok && tok->type == '+') {
      op = 1;
      isl_token_free(tok);
    } else {
      if (tok)
        isl_stream_push_token(s, tok);
      break;
    }
  }
 
  isl_space_free(space);
  return res;
error:
  isl_space_free(space);
  isl_token_free(tok);
  isl_pw_aff_free(res);
  return NULL;
}
 
/* Is "type" the type of a comparison operator between lists
 * of affine expressions?
 */
static int is_list_comparator_type(int type)
{
  switch (type) {
  case ISL_TOKEN_LEX_LT:
  case ISL_TOKEN_LEX_GT:
  case ISL_TOKEN_LEX_LE:
  case ISL_TOKEN_LEX_GE:
    return 1;
  default:
    return 0;
  }
}
 
static int is_comparator(struct isl_token *tok)
{
  if (!tok)
    return 0;
  if (is_list_comparator_type(tok->type))
    return 1;
 
  switch (tok->type) {
  case ISL_TOKEN_LT:
  case ISL_TOKEN_GT:
  case ISL_TOKEN_LE:
  case ISL_TOKEN_GE:
  case ISL_TOKEN_NE:
  case '=':
    return 1;
  default:
    return 0;
  }
}
 
static __isl_give isl_map *read_formula(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_map *map, int rational);
static __isl_give isl_pw_aff *accept_extended_affine(__isl_keep isl_stream *s,
  __isl_take isl_space *space, struct vars *v, int rational);
 
/* Accept a ternary operator, given the first argument.
 */
static __isl_give isl_pw_aff *accept_ternary(__isl_keep isl_stream *s,
  __isl_take isl_map *cond, struct vars *v, int rational)
{
  isl_space *space;
  isl_pw_aff *pwaff1 = NULL, *pwaff2 = NULL, *pa_cond;
 
  if (!cond)
    return NULL;
 
  if (isl_stream_eat(s, '?'))
    goto error;
 
  space = isl_space_wrap(isl_map_get_space(cond));
  pwaff1 = accept_extended_affine(s, space, v, rational);
  if (!pwaff1)
    goto error;
 
  if (isl_stream_eat(s, ':'))
    goto error;
 
  space = isl_pw_aff_get_domain_space(pwaff1);
  pwaff2 = accept_extended_affine(s, space, v, rational);
  if (!pwaff2)
    goto error;
 
  pa_cond = isl_set_indicator_function(isl_map_wrap(cond));
  return isl_pw_aff_cond(pa_cond, pwaff1, pwaff2);
error:
  isl_map_free(cond);
  isl_pw_aff_free(pwaff1);
  isl_pw_aff_free(pwaff2);
  return NULL;
}
 
/* Set *line and *col to those of the next token, if any.
 */
static void set_current_line_col(__isl_keep isl_stream *s, int *line, int *col)
{
  struct isl_token *tok;
 
  tok = isl_stream_next_token(s);
  if (!tok)
    return;
 
  *line = tok->line;
  *col = tok->col;
  isl_stream_push_token(s, tok);
}
 
/* Push a token encapsulating "pa" onto "s", with the given
 * line and column.
 */
static isl_stat push_aff(__isl_keep isl_stream *s, int line, int col,
  __isl_take isl_pw_aff *pa)
{
  struct isl_token *tok;
 
  tok = isl_token_new(s->ctx, line, col, 0);
  if (!tok)
    goto error;
  tok->type = ISL_TOKEN_AFF;
  tok->u.pwaff = pa;
  isl_stream_push_token(s, tok);
 
  return isl_stat_ok;
error:
  isl_pw_aff_free(pa);
  return isl_stat_error;
}
 
/* Is the next token a comparison operator?
 */
static int next_is_comparator(__isl_keep isl_stream *s)
{
  int is_comp;
  struct isl_token *tok;
 
  tok = isl_stream_next_token(s);
  if (!tok)
    return 0;
 
  is_comp = is_comparator(tok);
  isl_stream_push_token(s, tok);
 
  return is_comp;
}
 
/* Accept an affine expression that may involve ternary operators.
 * We first read an affine expression.
 * If it is not followed by a comparison operator, we simply return it.
 * Otherwise, we assume the affine expression is part of the first
 * argument of a ternary operator and try to parse that.
 */
static __isl_give isl_pw_aff *accept_extended_affine(__isl_keep isl_stream *s,
  __isl_take isl_space *space, struct vars *v, int rational)
{
  isl_map *cond;
  isl_pw_aff *pwaff;
  int line = -1, col = -1;
 
  set_current_line_col(s, &line, &col);
 
  pwaff = accept_affine(s, space, v);
  if (rational)
    pwaff = isl_pw_aff_set_rational(pwaff);
  if (!pwaff)
    return NULL;
  if (!next_is_comparator(s))
    return pwaff;
 
  space = isl_pw_aff_get_domain_space(pwaff);
  cond = isl_map_universe(isl_space_unwrap(space));
 
  if (push_aff(s, line, col, pwaff) < 0)
    cond = isl_map_free(cond);
  if (!cond)
    return NULL;
 
  cond = read_formula(s, v, cond, rational);
 
  return accept_ternary(s, cond, v, rational);
}
 
static __isl_give isl_map *read_var_def(__isl_keep isl_stream *s,
  __isl_take isl_map *map, enum isl_dim_type type, struct vars *v,
  int rational)
{
  isl_pw_aff *def;
  isl_size pos;
  isl_map *def_map;
 
  if (type == isl_dim_param)
    pos = isl_map_dim(map, isl_dim_param);
  else {
    pos = isl_map_dim(map, isl_dim_in);
    if (type == isl_dim_out) {
      isl_size n_out = isl_map_dim(map, isl_dim_out);
      if (pos < 0 || n_out < 0)
        return isl_map_free(map);
      pos += n_out;
    }
    type = isl_dim_in;
  }
  if (pos < 0)
    return isl_map_free(map);
  --pos;
 
  def = accept_extended_affine(s, isl_space_wrap(isl_map_get_space(map)),
          v, rational);
  def_map = isl_map_from_pw_aff(def);
  def_map = isl_map_equate(def_map, type, pos, isl_dim_out, 0);
  def_map = isl_set_unwrap(isl_map_domain(def_map));
 
  map = isl_map_intersect(map, def_map);
 
  return map;
}
 
static __isl_give isl_pw_aff_list *accept_affine_list(__isl_keep isl_stream *s,
  __isl_take isl_space *space, struct vars *v)
{
  isl_pw_aff *pwaff;
  isl_pw_aff_list *list;
  struct isl_token *tok = NULL;
 
  pwaff = accept_affine(s, isl_space_copy(space), v);
  list = isl_pw_aff_list_from_pw_aff(pwaff);
  if (!list)
    goto error;
 
  for (;;) {
    tok = isl_stream_next_token(s);
    if (!tok) {
      isl_stream_error(s, NULL, "unexpected EOF");
      goto error;
    }
    if (tok->type != ',') {
      isl_stream_push_token(s, tok);
      break;
    }
    isl_token_free(tok);
 
    pwaff = accept_affine(s, isl_space_copy(space), v);
    list = isl_pw_aff_list_concat(list,
        isl_pw_aff_list_from_pw_aff(pwaff));
    if (!list)
      goto error;
  }
 
  isl_space_free(space);
  return list;
error:
  isl_space_free(space);
  isl_pw_aff_list_free(list);
  return NULL;
}
 
static __isl_give isl_map *read_defined_var_list(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_map *map, int rational)
{
  struct isl_token *tok;
 
  while ((tok = isl_stream_next_token(s)) != NULL) {
    int p;
    int n = v->n;
 
    if (tok->type != ISL_TOKEN_IDENT)
      break;
 
    p = vars_pos(v, tok->u.s, -1);
    if (p < 0)
      goto error;
    if (p < n) {
      isl_stream_error(s, tok, "expecting unique identifier");
      goto error;
    }
 
    map = isl_map_add_dims(map, isl_dim_out, 1);
 
    isl_token_free(tok);
    tok = isl_stream_next_token(s);
    if (tok && tok->type == '=') {
      isl_token_free(tok);
      map = read_var_def(s, map, isl_dim_out, v, rational);
      tok = isl_stream_next_token(s);
    }
 
    if (!tok || tok->type != ',')
      break;
 
    isl_token_free(tok);
  }
  if (tok)
    isl_stream_push_token(s, tok);
 
  return map;
error:
  isl_token_free(tok);
  isl_map_free(map);
  return NULL;
}
 
static int next_is_tuple(__isl_keep isl_stream *s)
{
  struct isl_token *tok;
  int is_tuple;
 
  tok = isl_stream_next_token(s);
  if (!tok)
    return 0;
  if (tok->type == '[') {
    isl_stream_push_token(s, tok);
    return 1;
  }
  if (tok->type != ISL_TOKEN_IDENT && !tok->is_keyword) {
    isl_stream_push_token(s, tok);
    return 0;
  }
 
  is_tuple = isl_stream_next_token_is(s, '[');
 
  isl_stream_push_token(s, tok);
 
  return is_tuple;
}
 
/* Does the next token mark the end of a tuple element?
 */
static int next_is_end_tuple_element(__isl_keep isl_stream *s)
{
  return isl_stream_next_token_is(s, ',') ||
      isl_stream_next_token_is(s, ']');
}
 
/* Is the next token one that necessarily forms the start of a condition?
 */
static int next_is_condition_start(__isl_keep isl_stream *s)
{
  return isl_stream_next_token_is(s, ISL_TOKEN_EXISTS) ||
      isl_stream_next_token_is(s, ISL_TOKEN_NOT) ||
      isl_stream_next_token_is(s, ISL_TOKEN_TRUE) ||
      isl_stream_next_token_is(s, ISL_TOKEN_FALSE) ||
      isl_stream_next_token_is(s, ISL_TOKEN_MAP);
}
 
/* Is "pa" an expression in term of earlier dimensions?
 * The alternative is that the dimension is defined to be equal to itself,
 * meaning that it has a universe domain and an expression that depends
 * on itself.  "i" is the position of the expression in a sequence
 * of "n" expressions.  The final dimensions of "pa" correspond to
 * these "n" expressions.
 */
static isl_bool pw_aff_is_expr(__isl_keep isl_pw_aff *pa, int i, int n)
{
  isl_aff *aff;
 
  if (!pa)
    return isl_bool_error;
  if (pa->n != 1)
    return isl_bool_true;
  if (!isl_set_plain_is_universe(pa->p[0].set))
    return isl_bool_true;
 
  aff = pa->p[0].aff;
  if (isl_int_is_zero(aff->v->el[aff->v->size - n + i]))
    return isl_bool_true;
  return isl_bool_false;
}
 
/* Does the tuple contain any dimensions that are defined
 * in terms of earlier dimensions?
 */
static isl_bool tuple_has_expr(__isl_keep isl_multi_pw_aff *tuple)
{
  int i;
  isl_size n;
  isl_bool has_expr = isl_bool_false;
  isl_pw_aff *pa;
 
  n = isl_multi_pw_aff_dim(tuple, isl_dim_out);
  if (n < 0)
    return isl_bool_error;
  for (i = 0; i < n; ++i) {
    pa = isl_multi_pw_aff_get_pw_aff(tuple, i);
    has_expr = pw_aff_is_expr(pa, i, n);
    isl_pw_aff_free(pa);
    if (has_expr < 0 || has_expr)
      break;
  }
 
  return has_expr;
}
 
/* Set the name of dimension "pos" in "space" to "name".
 * During printing, we add primes if the same name appears more than once
 * to distinguish the occurrences.  Here, we remove those primes from "name"
 * before setting the name of the dimension.
 */
static __isl_give isl_space *space_set_dim_name(__isl_take isl_space *space,
  int pos, char *name)
{
  char *prime;
 
  if (!name)
    return space;
 
  prime = strchr(name, '\'');
  if (prime)
    *prime = '\0';
  space = isl_space_set_dim_name(space, isl_dim_out, pos, name);
  if (prime)
    *prime = '\'';
 
  return space;
}
 
/* Set the name of the last (output) dimension of "space" to "name",
 * ignoring any primes in "name".
 */
static __isl_give isl_space *space_set_last_dim_name(
  __isl_take isl_space *space, char *name)
{
  isl_size pos;
 
  pos = isl_space_dim(space, isl_dim_out);
  if (pos < 0)
    return isl_space_free(space);
  return space_set_dim_name(space, pos - 1, name);
}
 
/* Construct an isl_pw_aff defined on a "space" (with v->n variables)
 * that is equal to the last of those variables.
 */
static __isl_give isl_pw_aff *identity_tuple_el_on_space(
  __isl_take isl_space *space, struct vars *v)
{
  isl_aff *aff;
 
  aff = isl_aff_zero_on_domain(isl_local_space_from_space(space));
  aff = isl_aff_add_coefficient_si(aff, isl_dim_in, v->n - 1, 1);
  return isl_pw_aff_from_aff(aff);
}
 
/* Construct an isl_pw_aff defined on the domain space of "pa"
 * that is equal to the last variable in "v".
 *
 * That is, if D is the domain space of "pa", then construct
 *
 *  D[..., i] -> i.
 */
static __isl_give isl_pw_aff *init_range(__isl_keep isl_pw_aff *pa,
  struct vars *v)
{
  isl_space *space;
 
  space = isl_pw_aff_get_domain_space(pa);
  return identity_tuple_el_on_space(space, v);
}
 
/* Impose the lower bound "lower" on the variable represented by "range_pa".
 *
 * In particular, "range_pa" is of the form
 *
 *  D[..., i] -> i : C
 *
 * with D also the domains space of "lower' and "C" some constraints.
 *
 * Return the expression
 *
 *  D[..., i] -> i : C and i >= lower
 */
static __isl_give isl_pw_aff *set_lower(__isl_take isl_pw_aff *range_pa,
  __isl_take isl_pw_aff *lower)
{
  isl_set *range;
 
  range = isl_pw_aff_ge_set(isl_pw_aff_copy(range_pa), lower);
  return isl_pw_aff_intersect_domain(range_pa, range);
}
 
/* Impose the upper bound "upper" on the variable represented by "range_pa".
 *
 * In particular, "range_pa" is of the form
 *
 *  D[..., i] -> i : C
 *
 * with D also the domains space of "upper' and "C" some constraints.
 *
 * Return the expression
 *
 *  D[..., i] -> i : C and i <= upper
 */
static __isl_give isl_pw_aff *set_upper(__isl_take isl_pw_aff *range_pa,
  __isl_take isl_pw_aff *upper)
{
  isl_set *range;
 
  range = isl_pw_aff_le_set(isl_pw_aff_copy(range_pa), upper);
  return isl_pw_aff_intersect_domain(range_pa, range);
}
 
/* Construct a piecewise affine expression corresponding
 * to the last variable in "v" that is greater than or equal to "pa".
 *
 * In particular, if D is the domain space of "pa",
 * then construct the expression
 *
 *  D[..., i] -> i,
 *
 * impose lower bound "pa" and return
 *
 *  D[..., i] -> i : i >= pa
 */
static __isl_give isl_pw_aff *construct_lower(__isl_take isl_pw_aff *pa,
  struct vars *v)
{
  return set_lower(init_range(pa, v), pa);
}
 
/* Construct a piecewise affine expression corresponding
 * to the last variable in "v" that is smaller than or equal to "pa".
 *
 * In particular, if D is the domain space of "pa",
 * then construct the expression
 *
 *  D[..., i] -> i,
 *
 * impose lower bound "pa" and return
 *
 *  D[..., i] -> i : i <= pa
 */
static __isl_give isl_pw_aff *construct_upper(__isl_take isl_pw_aff *pa,
  struct vars *v)
{
  return set_upper(init_range(pa, v), pa);
}
 
/* Construct a piecewise affine expression corresponding
 * to the last variable in "v" that ranges between "pa" and "pa2".
 *
 * In particular, if D is the domain space of "pa" (and "pa2"),
 * then construct the expression
 *
 *  D[..., i] -> i,
 *
 * impose lower bound "pa" and upper bound "pa2" and return
 *
 *  D[..., i] -> i : pa <= i <= pa2
 */
static __isl_give isl_pw_aff *construct_range(__isl_take isl_pw_aff *pa,
  __isl_take isl_pw_aff *pa2, struct vars *v)
{
  return set_upper(set_lower(init_range(pa, v), pa), pa2);
}
 
static int resolve_paren_expr(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_map *map, int rational);
 
/* Given that the (piecewise) affine expression "pa"
 * has just been parsed, followed by a colon,
 * continue parsing as part of a piecewise affine expression.
 *
 * In particular, check if the colon is followed by a condition.
 * If so, parse the conditions(a) on "pa" and include them in the domain.
 * Otherwise, if the colon is followed by another (piecewise) affine expression
 * then consider the two expressions as endpoints of a range of values and
 * return a piecewise affine expression that takes values in that range.
 * Note that an affine expression followed by a comparison operator
 * is considered to be part of a condition.
 * If the colon is not followed by anything (inside the tuple element),
 * then consider "pa" as a lower bound on a range of values without upper bound
 * and return a piecewise affine expression that takes values in that range.
 */
static __isl_give isl_pw_aff *update_piecewise_affine_colon(
  __isl_take isl_pw_aff *pa, __isl_keep isl_stream *s,
  struct vars *v, int rational)
{
  isl_space *dom_space;
  isl_map *map;
 
  dom_space = isl_pw_aff_get_domain_space(pa);
  map = isl_map_universe(isl_space_from_domain(dom_space));
 
  if (isl_stream_next_token_is(s, '('))
    if (resolve_paren_expr(s, v, isl_map_copy(map), rational))
      goto error;
  if (next_is_end_tuple_element(s)) {
    isl_map_free(map);
    return construct_lower(pa, v);
  }
  if (!next_is_condition_start(s)) {
    int line = -1, col = -1;
    isl_space *space;
    isl_pw_aff *pa2;
 
    set_current_line_col(s, &line, &col);
    space = isl_space_wrap(isl_map_get_space(map));
    pa2 = accept_affine(s, space, v);
    if (rational)
      pa2 = isl_pw_aff_set_rational(pa2);
    if (!next_is_comparator(s)) {
      isl_map_free(map);
      pa2 = isl_pw_aff_domain_factor_domain(pa2);
      return construct_range(pa, pa2, v);
    }
    if (push_aff(s, line, col, pa2) < 0)
      goto error;
  }
 
  map = read_formula(s, v, map, rational);
  pa = isl_pw_aff_intersect_domain(pa, isl_map_domain(map));
 
  return pa;
error:
  isl_map_free(map);
  isl_pw_aff_free(pa);
  return NULL;
}
 
/* Accept a piecewise affine expression.
 *
 * At the outer level, the piecewise affine expression may be of the form
 *
 *  aff1 : condition1; aff2 : conditions2; ...
 *
 * or one of
 *
 *  aff :
 *  aff1 : aff2
 *  : aff
 *  :
 *
 * or simply
 *
 *  aff
 *
 * each of the affine expressions may in turn include ternary operators.
 *
 * If the first token is a colon, then the expression must be
 * ":" or ": aff2", depending on whether anything follows the colon
 * inside the tuple element.
 * The first is considered to represent an arbitrary value.
 * The second is considered to represent a range of values
 * with the given upper bound and no lower bound.
 *
 * There may be parentheses around some subexpression of "aff1"
 * around "aff1" itself, around "aff1 : condition1" and/or
 * around the entire piecewise affine expression.
 * We therefore remove the opening parenthesis (if any) from the stream
 * in case the closing parenthesis follows the colon, but if the closing
 * parenthesis is the first thing in the stream after the parsed affine
 * expression, we push the parsed expression onto the stream and parse
 * again in case the parentheses enclose some subexpression of "aff1".
 */
static __isl_give isl_pw_aff *accept_piecewise_affine(__isl_keep isl_stream *s,
  __isl_take isl_space *space, struct vars *v, int rational)
{
  isl_pw_aff *res;
  isl_space *res_space;
 
  if (isl_stream_eat_if_available(s, ':')) {
    if (next_is_end_tuple_element(s))
      return identity_tuple_el_on_space(space, v);
    else
      return construct_upper(accept_affine(s, space, v), v);
  }
 
  res_space = isl_space_from_domain(isl_space_copy(space));
  res_space = isl_space_add_dims(res_space, isl_dim_out, 1);
  res = isl_pw_aff_empty(res_space);
  do {
    isl_pw_aff *pa;
    int seen_paren;
    int line = -1, col = -1;
 
    set_current_line_col(s, &line, &col);
    seen_paren = isl_stream_eat_if_available(s, '(');
    if (seen_paren)
      pa = accept_piecewise_affine(s, isl_space_copy(space),
              v, rational);
    else
      pa = accept_extended_affine(s, isl_space_copy(space),
              v, rational);
    if (seen_paren && isl_stream_eat_if_available(s, ')')) {
      seen_paren = 0;
      if (push_aff(s, line, col, pa) < 0)
        goto error;
      pa = accept_extended_affine(s, isl_space_copy(space),
              v, rational);
    }
    if (pa && isl_stream_eat_if_available(s, ':'))
      pa = update_piecewise_affine_colon(pa, s, v, rational);
 
    res = isl_pw_aff_union_add(res, pa);
 
    if (!res || (seen_paren && isl_stream_eat(s, ')')))
      goto error;
  } while (isl_stream_eat_if_available(s, ';'));
 
  isl_space_free(space);
 
  return res;
error:
  isl_space_free(space);
  return isl_pw_aff_free(res);
}
 
/* Read an affine expression from "s" for use in read_tuple.
 *
 * accept_extended_affine requires a wrapped space as input.
 * read_tuple on the other hand expects each isl_pw_aff
 * to have an anonymous space.  We therefore adjust the space
 * of the isl_pw_aff before returning it.
 */
static __isl_give isl_pw_aff *read_tuple_var_def(__isl_keep isl_stream *s,
  struct vars *v, int rational)
{
  isl_space *space;
  isl_pw_aff *def;
 
  space = isl_space_wrap(isl_space_alloc(s->ctx, 0, v->n, 0));
 
  def = accept_piecewise_affine(s, space, v, rational);
  def = isl_pw_aff_domain_factor_domain(def);
 
  return def;
}
 
/* Read a list of tuple elements by calling "read_el" on each of them and
 * return a space with the same number of set dimensions derived from
 * the parameter space "space" and possibly updated by "read_el".
 * The elements in the list are separated by either "," or "][".
 * If "comma" is set then only "," is allowed.
 */
static __isl_give isl_space *read_tuple_list(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_space *space, int rational, int comma,
  __isl_give isl_space *(*read_el)(__isl_keep isl_stream *s,
    struct vars *v, __isl_take isl_space *space, int rational,
    void *user),
  void *user)
{
  if (!space)
    return NULL;
 
  space = isl_space_set_from_params(space);
 
  if (isl_stream_next_token_is(s, ']'))
    return space;
 
  for (;;) {
    struct isl_token *tok;
 
    space = isl_space_add_dims(space, isl_dim_set, 1);
 
    space = read_el(s, v, space, rational, user);
    if (!space)
      return NULL;
 
    tok = isl_stream_next_token(s);
    if (!comma && tok && tok->type == ']' &&
        isl_stream_next_token_is(s, '[')) {
      isl_token_free(tok);
      tok = isl_stream_next_token(s);
    } else if (!tok || tok->type != ',') {
      if (tok)
        isl_stream_push_token(s, tok);
      break;
    }
 
    isl_token_free(tok);
  }
 
  return space;
}
 
/* Read a tuple space from "s" derived from the parameter space "space".
 * Call "read_el" on each element in the tuples.
 */
static __isl_give isl_space *read_tuple_space(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_space *space, int rational, int comma,
  __isl_give isl_space *(*read_el)(__isl_keep isl_stream *s,
    struct vars *v, __isl_take isl_space *space, int rational,
    void *user),
  void *user)
{
  struct isl_token *tok;
  char *name = NULL;
  isl_space *res = NULL;
 
  tok = isl_stream_next_token(s);
  if (!tok)
    goto error;
  if (tok->type == ISL_TOKEN_IDENT || tok->is_keyword) {
    name = strdup(tok->u.s);
    isl_token_free(tok);
    if (!name)
      goto error;
  } else
    isl_stream_push_token(s, tok);
  if (isl_stream_eat(s, '['))
    goto error;
  if (next_is_tuple(s)) {
    isl_space *out;
    res = read_tuple_space(s, v, isl_space_copy(space),
          rational, comma, read_el, user);
    if (isl_stream_eat(s, ISL_TOKEN_TO))
      goto error;
    out = read_tuple_space(s, v, isl_space_copy(space),
          rational, comma, read_el, user);
    res = isl_space_product(res, out);
  } else
    res = read_tuple_list(s, v, isl_space_copy(space),
          rational, comma, read_el, user);
  if (!res || isl_stream_eat(s, ']'))
    goto error;
 
  if (name) {
    res = isl_space_set_tuple_name(res, isl_dim_set, name);
    free(name);
  }
 
  isl_space_free(space);
  return res;
error:
  free(name);
  isl_space_free(res);
  isl_space_free(space);
  return NULL;
}
 
/* Construct an isl_pw_aff defined on a space with v->n variables
 * that is equal to the last of those variables.
 */
static __isl_give isl_pw_aff *identity_tuple_el(struct vars *v)
{
  isl_space *space;
 
  space = isl_space_set_alloc(v->ctx, 0, v->n);
  return identity_tuple_el_on_space(space, v);
}
 
/* This function is called for each element in a tuple inside read_tuple.
 * Add a new variable to "v" and construct a corresponding isl_pw_aff defined
 * over a space containing all variables in "v" defined so far.
 * The isl_pw_aff expresses the new variable in terms of earlier variables
 * if a definition is provided.  Otherwise, it is represented as being
 * equal to itself.
 * Add the isl_pw_aff to *list.
 * If the new variable was named, then adjust "space" accordingly and
 * return the updated space.
 */
static __isl_give isl_space *read_tuple_pw_aff_el(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_space *space, int rational, void *user)
{
  isl_pw_aff_list **list = (isl_pw_aff_list **) user;
  isl_pw_aff *pa;
  struct isl_token *tok;
  int new_name = 0;
 
  tok = next_token(s);
  if (!tok) {
    isl_stream_error(s, NULL, "unexpected EOF");
    return isl_space_free(space);
  }
 
  if (tok->type == ISL_TOKEN_IDENT) {
    int n = v->n;
    int p = vars_pos(v, tok->u.s, -1);
    if (p < 0)
      goto error;
    new_name = p >= n;
  }
 
  if (tok->type == '*') {
    if (vars_add_anon(v) < 0)
      goto error;
    isl_token_free(tok);
    pa = identity_tuple_el(v);
  } else if (new_name) {
    space = space_set_last_dim_name(space, v->v->name);
    isl_token_free(tok);
    if (isl_stream_eat_if_available(s, '='))
      pa = read_tuple_var_def(s, v, rational);
    else
      pa = identity_tuple_el(v);
  } else {
    isl_stream_push_token(s, tok);
    tok = NULL;
    if (vars_add_anon(v) < 0)
      goto error;
    pa = read_tuple_var_def(s, v, rational);
  }
 
  *list = isl_pw_aff_list_add(*list, pa);
  if (!*list)
    return isl_space_free(space);
 
  return space;
error:
  isl_token_free(tok);
  return isl_space_free(space);
}
 
/* Read a tuple and represent it as an isl_multi_pw_aff.
 * The range space of the isl_multi_pw_aff is the space of the tuple.
 * The domain space is an anonymous space
 * with a dimension for each variable in the set of variables in "v",
 * including the variables in the range.
 * If a given dimension is not defined in terms of earlier dimensions in
 * the input, then the corresponding isl_pw_aff is set equal to one time
 * the variable corresponding to the dimension being defined.
 *
 * The elements in the tuple are collected in a list by read_tuple_pw_aff_el.
 * Each element in this list is defined over a space representing
 * the variables defined so far.  We need to adjust the earlier
 * elements to have as many variables in the domain as the final
 * element in the list.
 */
static __isl_give isl_multi_pw_aff *read_tuple(__isl_keep isl_stream *s,
  struct vars *v, int rational, int comma)
{
  int i;
  isl_size n;
  isl_space *space;
  isl_pw_aff_list *list;
 
  space = isl_space_params_alloc(v->ctx, 0);
  list = isl_pw_aff_list_alloc(s->ctx, 0);
  space = read_tuple_space(s, v, space, rational, comma,
        &read_tuple_pw_aff_el, &list);
  n = isl_space_dim(space, isl_dim_set);
  if (n < 0)
    space = isl_space_free(space);
  for (i = 0; i + 1 < n; ++i) {
    isl_pw_aff *pa;
 
    pa = isl_pw_aff_list_get_pw_aff(list, i);
    pa = isl_pw_aff_add_dims(pa, isl_dim_in, n - (i + 1));
    list = isl_pw_aff_list_set_pw_aff(list, i, pa);
  }
 
  space = isl_space_from_range(space);
  space = isl_space_add_dims(space, isl_dim_in, v->n);
  return isl_multi_pw_aff_from_pw_aff_list(space, list);
}
 
/* Add the tuple represented by the isl_multi_pw_aff "tuple" to "map".
 * We first create the appropriate space in "map" based on the range
 * space of this isl_multi_pw_aff.  Then, we add equalities based
 * on the affine expressions.  These live in an anonymous space,
 * however, so we first need to reset the space to that of "map".
 */
static __isl_give isl_map *map_from_tuple(__isl_take isl_multi_pw_aff *tuple,
  __isl_take isl_map *map, enum isl_dim_type type, struct vars *v,
  int rational)
{
  int i;
  isl_size n;
  isl_ctx *ctx;
  isl_space *space = NULL;
 
  n = isl_multi_pw_aff_dim(tuple, isl_dim_out);
  if (!map || n < 0)
    goto error;
  ctx = isl_multi_pw_aff_get_ctx(tuple);
  space = isl_space_range(isl_multi_pw_aff_get_space(tuple));
  if (!space)
    goto error;
 
  if (type == isl_dim_param) {
    if (isl_space_has_tuple_name(space, isl_dim_set) ||
        isl_space_is_wrapping(space)) {
      isl_die(ctx, isl_error_invalid,
        "parameter tuples cannot be named or nested",
        goto error);
    }
    map = isl_map_add_dims(map, type, n);
    for (i = 0; i < n; ++i) {
      isl_id *id;
      if (!isl_space_has_dim_name(space, isl_dim_set, i))
        isl_die(ctx, isl_error_invalid,
          "parameters must be named",
          goto error);
      id = isl_space_get_dim_id(space, isl_dim_set, i);
      map = isl_map_set_dim_id(map, isl_dim_param, i, id);
    }
  } else if (type == isl_dim_in) {
    isl_set *set;
 
    set = isl_set_universe(isl_space_copy(space));
    if (rational)
      set = isl_set_set_rational(set);
    set = isl_set_intersect_params(set, isl_map_params(map));
    map = isl_map_from_domain(set);
  } else {
    isl_set *set;
 
    set = isl_set_universe(isl_space_copy(space));
    if (rational)
      set = isl_set_set_rational(set);
    map = isl_map_from_domain_and_range(isl_map_domain(map), set);
  }
 
  for (i = 0; i < n; ++i) {
    isl_pw_aff *pa;
    isl_space *space;
    isl_aff *aff;
    isl_set *set;
    isl_map *map_i;
 
    pa = isl_multi_pw_aff_get_pw_aff(tuple, i);
    space = isl_pw_aff_get_domain_space(pa);
    aff = isl_aff_zero_on_domain(isl_local_space_from_space(space));
    aff = isl_aff_add_coefficient_si(aff,
            isl_dim_in, v->n - n + i, -1);
    pa = isl_pw_aff_add(pa, isl_pw_aff_from_aff(aff));
    if (rational)
      pa = isl_pw_aff_set_rational(pa);
    set = isl_pw_aff_zero_set(pa);
    map_i = isl_map_from_range(set);
    map_i = isl_map_reset_space(map_i, isl_map_get_space(map));
    map = isl_map_intersect(map, map_i);
  }
 
  isl_space_free(space);
  isl_multi_pw_aff_free(tuple);
  return map;
error:
  isl_space_free(space);
  isl_multi_pw_aff_free(tuple);
  isl_map_free(map);
  return NULL;
}
 
/* Read a tuple from "s" and add it to "map".
 * The tuple is initially represented as an isl_multi_pw_aff and
 * then added to "map".
 */
static __isl_give isl_map *read_map_tuple(__isl_keep isl_stream *s,
  __isl_take isl_map *map, enum isl_dim_type type, struct vars *v,
  int comma)
{
  isl_bool rational;
  isl_multi_pw_aff *tuple;
 
  rational = isl_map_is_rational(map);
  if (rational < 0)
    return isl_map_free(map);
  tuple = read_tuple(s, v, rational, comma);
  if (!tuple)
    return isl_map_free(map);
 
  return map_from_tuple(tuple, map, type, v, rational);
}
 
/* Read the parameter domain of an expression from "s" (if any) and
 * check that it does not involve any constraints.
 * "v" contains a description of the identifiers parsed so far
 * (of which there should not be any at this point) and is extended
 * by this function.
 */
static __isl_give isl_set *read_universe_params(__isl_keep isl_stream *s,
  struct vars *v)
{
  isl_set *dom;
 
  dom = isl_set_universe(isl_space_params_alloc(s->ctx, 0));
  if (next_is_tuple(s)) {
    dom = read_map_tuple(s, dom, isl_dim_param, v, 0);
    if (isl_stream_eat(s, ISL_TOKEN_TO))
      return isl_set_free(dom);
  }
  if (!isl_set_plain_is_universe(dom))
    isl_die(s->ctx, isl_error_invalid,
      "expecting universe parameter domain",
      return isl_set_free(dom));
 
  return dom;
}
 
/* Read the parameter domain of an expression from "s" (if any),
 * check that it does not involve any constraints and return its space.
 * "v" contains a description of the identifiers parsed so far
 * (of which there should not be any at this point) and is extended
 * by this function.
 */
static __isl_give isl_space *read_params(__isl_keep isl_stream *s,
  struct vars *v)
{
  isl_space *space;
  isl_set *set;
 
  set = read_universe_params(s, v);
  space = isl_set_get_space(set);
  isl_set_free(set);
 
  return space;
}
 
/* This function is called for each element in a tuple inside read_space_tuples.
 * Add a new variable to "v" and adjust "space" accordingly
 * if the variable has a name.
 */
static __isl_give isl_space *read_tuple_id(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_space *space, int rational, void *user)
{
  struct isl_token *tok;
 
  tok = next_token(s);
  if (!tok) {
    isl_stream_error(s, NULL, "unexpected EOF");
    return isl_space_free(space);
  }
 
  if (tok->type == ISL_TOKEN_IDENT) {
    int n = v->n;
    int p = vars_pos(v, tok->u.s, -1);
    if (p < 0)
      goto error;
    if (p < n) {
      isl_stream_error(s, tok, "expecting fresh identifier");
      goto error;
    }
    space = space_set_last_dim_name(space, v->v->name);
  } else if (tok->type == '*') {
    if (vars_add_anon(v) < 0)
      goto error;
  } else {
    isl_stream_error(s, tok, "expecting identifier or '*'");
    goto error;
  }
 
  isl_token_free(tok);
  return space;
error:
  isl_token_free(tok);
  return isl_space_free(space);
}
 
/* Given a parameter space "params", extend it with one or two tuples
 * read from "s".
 * "v" contains a description of the identifiers parsed so far and is extended
 * by this function.
 */
static __isl_give isl_space *read_space_tuples(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_space *params)
{
  isl_space *space, *ran;
 
  space = read_tuple_space(s, v, isl_space_copy(params), 1, 1,
        &read_tuple_id, NULL);
  if (isl_stream_eat_if_available(s, ISL_TOKEN_TO)) {
    ran = read_tuple_space(s, v, isl_space_copy(params), 1, 1,
          &read_tuple_id, NULL);
    space = isl_space_unwrap(isl_space_product(space, ran));
  }
  isl_space_free(params);
 
  return space;
}
 
/* Read an isl_space object from "s".
 *
 * First read the parameters (if any).
 *
 * Then check if the description is of the special form "{ : }",
 * in which case it represents a parameter space.
 * Otherwise, it has one or two tuples.
 */
__isl_give isl_space *isl_stream_read_space(__isl_keep isl_stream *s)
{
  struct vars *v;
  isl_space *space;
 
  v = vars_new(s->ctx);
  if (!v)
    return NULL;
  space = read_params(s, v);
 
  if (isl_stream_eat(s, '{'))
    goto error;
 
  if (!isl_stream_eat_if_available(s, ':'))
    space = read_space_tuples(s, v, space);
 
  if (isl_stream_eat(s, '}'))
    goto error;
 
  vars_free(v);
  return space;
error:
  vars_free(v);
  isl_space_free(space);
  return NULL;
}
 
#undef TYPE_BASE
#define TYPE_BASE space
#include "isl_read_from_str_templ.c"
 
/* Given two equal-length lists of piecewise affine expression with the space
 * of "set" as domain, construct a set in the same space that expresses
 * that "left" and "right" satisfy the comparison "type".
 *
 * A space is constructed of the same dimension as the number of elements
 * in the two lists.  The comparison is then expressed in a map from
 * this space to itself and wrapped into a set.  Finally the two lists
 * of piecewise affine expressions are plugged into this set.
 *
 * Let S be the space of "set" and T the constructed space.
 * The lists are first changed into two isl_multi_pw_affs in S -> T and
 * then combined into an isl_multi_pw_aff in S -> [T -> T],
 * while the comparison is first expressed in T -> T, then [T -> T]
 * and finally in S.
 */
static __isl_give isl_set *list_cmp(__isl_keep isl_set *set, int type,
  __isl_take isl_pw_aff_list *left, __isl_take isl_pw_aff_list *right)
{
  isl_space *space;
  isl_size n;
  isl_multi_pw_aff *mpa1, *mpa2;
 
  n = isl_pw_aff_list_n_pw_aff(left);
  if (!set || n < 0 || !right)
    goto error;
 
  space = isl_set_get_space(set);
  space = isl_space_from_domain(space);
  space = isl_space_add_dims(space, isl_dim_out, n);
  mpa1 = isl_multi_pw_aff_from_pw_aff_list(isl_space_copy(space), left);
  mpa2 = isl_multi_pw_aff_from_pw_aff_list(isl_space_copy(space), right);
  mpa1 = isl_multi_pw_aff_range_product(mpa1, mpa2);
 
  space = isl_space_range(space);
  switch (type) {
  case ISL_TOKEN_LEX_LT:
    set = isl_map_wrap(isl_map_lex_lt(space));
    break;
  case ISL_TOKEN_LEX_GT:
    set = isl_map_wrap(isl_map_lex_gt(space));
    break;
  case ISL_TOKEN_LEX_LE:
    set = isl_map_wrap(isl_map_lex_le(space));
    break;
  case ISL_TOKEN_LEX_GE:
    set = isl_map_wrap(isl_map_lex_ge(space));
    break;
  default:
    isl_multi_pw_aff_free(mpa1);
    isl_space_free(space);
    isl_die(isl_set_get_ctx(set), isl_error_internal,
      "unhandled list comparison type", return NULL);
  }
  set = isl_set_preimage_multi_pw_aff(set, mpa1);
  return set;
error:
  isl_pw_aff_list_free(left);
  isl_pw_aff_list_free(right);
  return NULL;
}
 
/* Construct constraints of the form
 *
 *  a op b
 *
 * where a is an element in "left", op is an operator of type "type" and
 * b is an element in "right", add the constraints to "set" and return
 * the result.
 * "rational" is set if the constraints should be treated as
 * a rational constraints.
 *
 * If "type" is the type of a comparison operator between lists
 * of affine expressions, then a single (compound) constraint
 * is constructed by list_cmp instead.
 */
static __isl_give isl_set *construct_constraints(
  __isl_take isl_set *set, int type,
  __isl_keep isl_pw_aff_list *left, __isl_keep isl_pw_aff_list *right,
  int rational)
{
  isl_set *cond;
 
  left = isl_pw_aff_list_copy(left);
  right = isl_pw_aff_list_copy(right);
  if (rational) {
    left = isl_pw_aff_list_set_rational(left);
    right = isl_pw_aff_list_set_rational(right);
  }
  if (is_list_comparator_type(type))
    cond = list_cmp(set, type, left, right);
  else if (type == ISL_TOKEN_LE)
    cond = isl_pw_aff_list_le_set(left, right);
  else if (type == ISL_TOKEN_GE)
    cond = isl_pw_aff_list_ge_set(left, right);
  else if (type == ISL_TOKEN_LT)
    cond = isl_pw_aff_list_lt_set(left, right);
  else if (type == ISL_TOKEN_GT)
    cond = isl_pw_aff_list_gt_set(left, right);
  else if (type == ISL_TOKEN_NE)
    cond = isl_pw_aff_list_ne_set(left, right);
  else
    cond = isl_pw_aff_list_eq_set(left, right);
 
  return isl_set_intersect(set, cond);
}
 
/* Read a constraint from "s", add it to "map" and return the result.
 * "v" contains a description of the identifiers parsed so far.
 * "rational" is set if the constraint should be treated as
 * a rational constraint.
 * The constraint read from "s" may be applied to multiple pairs
 * of affine expressions and may be chained.
 * In particular, a list of affine expressions is read, followed
 * by a comparison operator and another list of affine expressions.
 * The comparison operator is then applied to each pair of elements
 * in the two lists and the results are added to "map".
 * However, if the operator expects two lists of affine expressions,
 * then it is applied directly to those lists and the two lists
 * are required to have the same length.
 * If the next token is another comparison operator, then another
 * list of affine expressions is read and the process repeats.
 *
 * The processing is performed on a wrapped copy of "map" because
 * an affine expression cannot have a binary relation as domain.
 */
static __isl_give isl_map *add_constraint(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_map *map, int rational)
{
  struct isl_token *tok;
  int type;
  isl_pw_aff_list *list1 = NULL, *list2 = NULL;
  isl_size n1, n2;
  isl_set *set;
 
  set = isl_map_wrap(map);
  list1 = accept_affine_list(s, isl_set_get_space(set), v);
  if (!list1)
    goto error;
  tok = isl_stream_next_token(s);
  if (!is_comparator(tok)) {
    isl_stream_error(s, tok, "missing operator");
    if (tok)
      isl_stream_push_token(s, tok);
    goto error;
  }
  type = tok->type;
  isl_token_free(tok);
  for (;;) {
    list2 = accept_affine_list(s, isl_set_get_space(set), v);
    n1 = isl_pw_aff_list_n_pw_aff(list1);
    n2 = isl_pw_aff_list_n_pw_aff(list2);
    if (n1 < 0 || n2 < 0)
      goto error;
    if (is_list_comparator_type(type) && n1 != n2) {
      isl_stream_error(s, NULL,
          "list arguments not of same size");
      goto error;
    }
 
    set = construct_constraints(set, type, list1, list2, rational);
    isl_pw_aff_list_free(list1);
    list1 = list2;
 
    if (!next_is_comparator(s))
      break;
    tok = isl_stream_next_token(s);
    type = tok->type;
    isl_token_free(tok);
  }
  isl_pw_aff_list_free(list1);
 
  return isl_set_unwrap(set);
error:
  isl_pw_aff_list_free(list1);
  isl_pw_aff_list_free(list2);
  isl_set_free(set);
  return NULL;
}
 
static __isl_give isl_map *read_exists(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_map *map, int rational)
{
  int n = v->n;
  int seen_paren = isl_stream_eat_if_available(s, '(');
 
  map = isl_map_from_domain(isl_map_wrap(map));
  map = read_defined_var_list(s, v, map, rational);
 
  if (isl_stream_eat(s, ':'))
    goto error;
 
  map = read_formula(s, v, map, rational);
  map = isl_set_unwrap(isl_map_domain(map));
 
  vars_drop(v, v->n - n);
  if (seen_paren && isl_stream_eat(s, ')'))
    goto error;
 
  return map;
error:
  isl_map_free(map);
  return NULL;
}
 
/* Parse an expression between parentheses and push the result
 * back on the stream.
 *
 * The parsed expression may be either an affine expression
 * or a condition.  The first type is pushed onto the stream
 * as an isl_pw_aff, while the second is pushed as an isl_map.
 *
 * If the initial token indicates the start of a condition,
 * we parse it as such.
 * Otherwise, we first parse an affine expression and push
 * that onto the stream.  If the affine expression covers the
 * entire expression between parentheses, we return.
 * Otherwise, we assume that the affine expression is the
 * start of a condition and continue parsing.
 */
static int resolve_paren_expr(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_map *map, int rational)
{
  struct isl_token *tok, *tok2;
  int has_paren;
  int line, col;
  isl_pw_aff *pwaff;
 
  tok = isl_stream_next_token(s);
  if (!tok || tok->type != '(')
    goto error;
 
  if (isl_stream_next_token_is(s, '('))
    if (resolve_paren_expr(s, v, isl_map_copy(map), rational))
      goto error;
 
  if (next_is_condition_start(s)) {
    map = read_formula(s, v, map, rational);
    if (isl_stream_eat(s, ')'))
      goto error;
    tok->type = ISL_TOKEN_MAP;
    tok->u.map = map;
    isl_stream_push_token(s, tok);
    return 0;
  }
 
  tok2 = isl_stream_next_token(s);
  if (!tok2)
    goto error;
  line = tok2->line;
  col = tok2->col;
  isl_stream_push_token(s, tok2);
 
  pwaff = accept_affine(s, isl_space_wrap(isl_map_get_space(map)), v);
  if (!pwaff)
    goto error;
 
  has_paren = isl_stream_eat_if_available(s, ')');
 
  if (push_aff(s, line, col, pwaff) < 0)
    goto error;
 
  if (has_paren) {
    isl_token_free(tok);
    isl_map_free(map);
    return 0;
  }
 
  map = read_formula(s, v, map, rational);
  if (isl_stream_eat(s, ')'))
    goto error;
 
  tok->type = ISL_TOKEN_MAP;
  tok->u.map = map;
  isl_stream_push_token(s, tok);
 
  return 0;
error:
  isl_token_free(tok);
  isl_map_free(map);
  return -1;
}
 
static __isl_give isl_map *read_conjunct(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_map *map, int rational)
{
  if (isl_stream_next_token_is(s, '('))
    if (resolve_paren_expr(s, v, isl_map_copy(map), rational))
      goto error;
 
  if (isl_stream_next_token_is(s, ISL_TOKEN_MAP)) {
    struct isl_token *tok;
    tok = isl_stream_next_token(s);
    if (!tok)
      goto error;
    isl_map_free(map);
    map = isl_map_copy(tok->u.map);
    isl_token_free(tok);
    return map;
  }
 
  if (isl_stream_eat_if_available(s, ISL_TOKEN_EXISTS))
    return read_exists(s, v, map, rational);
 
  if (isl_stream_eat_if_available(s, ISL_TOKEN_TRUE))
    return map;
 
  if (isl_stream_eat_if_available(s, ISL_TOKEN_FALSE)) {
    isl_space *space = isl_map_get_space(map);
    isl_map_free(map);
    return isl_map_empty(space);
  }
    
  return add_constraint(s, v, map, rational);
error:
  isl_map_free(map);
  return NULL;
}
 
static __isl_give isl_map *read_conjuncts(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_map *map, int rational)
{
  isl_map *res;
  int negate;
 
  negate = isl_stream_eat_if_available(s, ISL_TOKEN_NOT);
  res = read_conjunct(s, v, isl_map_copy(map), rational);
  if (negate)
    res = isl_map_subtract(isl_map_copy(map), res);
 
  while (res && isl_stream_eat_if_available(s, ISL_TOKEN_AND)) {
    isl_map *res_i;
 
    negate = isl_stream_eat_if_available(s, ISL_TOKEN_NOT);
    res_i = read_conjunct(s, v, isl_map_copy(map), rational);
    if (negate)
      res = isl_map_subtract(res, res_i);
    else
      res = isl_map_intersect(res, res_i);
  }
 
  isl_map_free(map);
  return res;
}
 
static __isl_give isl_map *read_disjuncts(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_map *map, int rational)
{
  isl_map *res;
 
  if (isl_stream_next_token_is(s, '}'))
    return map;
 
  res = read_conjuncts(s, v, isl_map_copy(map), rational);
  while (isl_stream_eat_if_available(s, ISL_TOKEN_OR)) {
    isl_map *res_i;
 
    res_i = read_conjuncts(s, v, isl_map_copy(map), rational);
    res = isl_map_union(res, res_i);
  }
 
  isl_map_free(map);
  return res;
}
 
/* Read a first order formula from "s", add the corresponding
 * constraints to "map" and return the result.
 *
 * In particular, read a formula of the form
 *
 *  a
 *
 * or
 *
 *  a implies b
 *
 * where a and b are disjunctions.
 *
 * In the first case, map is replaced by
 *
 *  map \cap { [..] : a }
 *
 * In the second case, it is replaced by
 *
 *  (map \setminus { [..] : a}) \cup (map \cap { [..] : b })
 */
static __isl_give isl_map *read_formula(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_map *map, int rational)
{
  isl_map *res;
 
  res = read_disjuncts(s, v, isl_map_copy(map), rational);
 
  if (isl_stream_eat_if_available(s, ISL_TOKEN_IMPLIES)) {
    isl_map *res2;
 
    res = isl_map_subtract(isl_map_copy(map), res);
    res2 = read_disjuncts(s, v, map, rational);
    res = isl_map_union(res, res2);
  } else
    isl_map_free(map);
 
  return res;
}
 
static isl_size polylib_pos_to_isl_pos(__isl_keep isl_basic_map *bmap, int pos)
{
  isl_size n_out, n_in, n_param, n_div;
 
  n_param = isl_basic_map_dim(bmap, isl_dim_param);
  n_in = isl_basic_map_dim(bmap, isl_dim_in);
  n_out = isl_basic_map_dim(bmap, isl_dim_out);
  n_div = isl_basic_map_dim(bmap, isl_dim_div);
  if (n_param < 0 || n_in < 0 || n_out < 0 || n_div < 0)
    return isl_size_error;
 
  if (pos < n_out)
    return 1 + n_param + n_in + pos;
  pos -= n_out;
 
  if (pos < n_in)
    return 1 + n_param + pos;
  pos -= n_in;
 
  if (pos < n_div)
    return 1 + n_param + n_in + n_out + pos;
  pos -= n_div;
 
  if (pos < n_param)
    return 1 + pos;
 
  return 0;
}
 
static __isl_give isl_basic_map *basic_map_read_polylib_constraint(
  __isl_keep isl_stream *s, __isl_take isl_basic_map *bmap)
{
  int j;
  struct isl_token *tok;
  int type;
  int k;
  isl_int *c;
  isl_size total;
 
  if (!bmap)
    return NULL;
 
  tok = isl_stream_next_token(s);
  if (!tok || tok->type != ISL_TOKEN_VALUE) {
    isl_stream_error(s, tok, "expecting coefficient");
    isl_token_free(tok);
    goto error;
  }
  if (!tok->on_new_line) {
    isl_stream_error(s, tok, "coefficient should appear on new line");
    isl_token_free(tok);
    goto error;
  }
 
  type = isl_int_get_si(tok->u.v);
  isl_token_free(tok);
 
  isl_assert(s->ctx, type == 0 || type == 1, goto error);
  if (type == 0) {
    k = isl_basic_map_alloc_equality(bmap);
    c = bmap->eq[k];
  } else {
    k = isl_basic_map_alloc_inequality(bmap);
    c = bmap->ineq[k];
  }
  if (k < 0)
    goto error;
 
  total = isl_basic_map_dim(bmap, isl_dim_all);
  if (total < 0)
    return isl_basic_map_free(bmap);
  for (j = 0; j < 1 + total; ++j) {
    isl_size pos;
    tok = next_signed_value_on_same_line(s,
          "expecting coefficient on same line");
    if (!tok)
      goto error;
    pos = polylib_pos_to_isl_pos(bmap, j);
    if (pos >= 0)
      isl_int_set(c[pos], tok->u.v);
    isl_token_free(tok);
    if (pos < 0)
      return isl_basic_map_free(bmap);
  }
 
  return bmap;
error:
  isl_basic_map_free(bmap);
  return NULL;
}
 
static __isl_give isl_basic_map *basic_map_read_polylib(
  __isl_keep isl_stream *s)
{
  int i;
  struct isl_token *tok;
  struct isl_token *tok2;
  int n_row, n_col;
  int on_new_line;
  unsigned in = 0, out, local = 0;
  struct isl_basic_map *bmap = NULL;
  int nparam = 0;
 
  tok = isl_stream_next_token(s);
  if (!tok) {
    isl_stream_error(s, NULL, "unexpected EOF");
    return NULL;
  }
  tok2 = isl_stream_next_token(s);
  if (!tok2) {
    isl_token_free(tok);
    isl_stream_error(s, NULL, "unexpected EOF");
    return NULL;
  }
  if (tok->type != ISL_TOKEN_VALUE || tok2->type != ISL_TOKEN_VALUE) {
    isl_token_free(tok2);
    isl_token_free(tok);
    isl_stream_error(s, NULL,
         "expecting constraint matrix dimensions");
    return NULL;
  }
  n_row = isl_int_get_si(tok->u.v);
  n_col = isl_int_get_si(tok2->u.v);
  on_new_line = tok2->on_new_line;
  isl_token_free(tok2);
  isl_token_free(tok);
  isl_assert(s->ctx, !on_new_line, return NULL);
  isl_assert(s->ctx, n_row >= 0, return NULL);
  isl_assert(s->ctx, n_col >= 2 + nparam, return NULL);
  tok = isl_stream_next_token_on_same_line(s);
  if (tok) {
    if (tok->type != ISL_TOKEN_VALUE) {
      isl_stream_error(s, tok,
            "expecting number of output dimensions");
      isl_token_free(tok);
      goto error;
    }
    out = isl_int_get_si(tok->u.v);
    isl_token_free(tok);
 
    tok = isl_stream_next_token_on_same_line(s);
    if (!tok || tok->type != ISL_TOKEN_VALUE) {
      isl_stream_error(s, tok,
            "expecting number of input dimensions");
      isl_token_free(tok);
      goto error;
    }
    in = isl_int_get_si(tok->u.v);
    isl_token_free(tok);
 
    tok = isl_stream_next_token_on_same_line(s);
    if (!tok || tok->type != ISL_TOKEN_VALUE) {
      isl_stream_error(s, tok,
            "expecting number of existentials");
      isl_token_free(tok);
      goto error;
    }
    local = isl_int_get_si(tok->u.v);
    isl_token_free(tok);
 
    tok = isl_stream_next_token_on_same_line(s);
    if (!tok || tok->type != ISL_TOKEN_VALUE) {
      isl_stream_error(s, tok,
            "expecting number of parameters");
      isl_token_free(tok);
      goto error;
    }
    nparam = isl_int_get_si(tok->u.v);
    isl_token_free(tok);
    if (n_col != 1 + out + in + local + nparam + 1) {
      isl_stream_error(s, NULL,
            "dimensions don't match");
      goto error;
    }
  } else
    out = n_col - 2 - nparam;
  bmap = isl_basic_map_alloc(s->ctx, nparam, in, out, local, n_row, n_row);
  if (!bmap)
    return NULL;
 
  for (i = 0; i < local; ++i) {
    int k = isl_basic_map_alloc_div(bmap);
    if (k < 0)
      goto error;
    isl_seq_clr(bmap->div[k], 1 + 1 + nparam + in + out + local);
  }
 
  for (i = 0; i < n_row; ++i)
    bmap = basic_map_read_polylib_constraint(s, bmap);
 
  if (!bmap)
    return NULL;
 
  tok = isl_stream_next_token_on_same_line(s);
  if (tok) {
    isl_stream_error(s, tok, "unexpected extra token on line");
    isl_token_free(tok);
    goto error;
  }
 
  bmap = isl_basic_map_simplify(bmap);
  bmap = isl_basic_map_finalize(bmap);
  return bmap;
error:
  isl_basic_map_free(bmap);
  return NULL;
}
 
static __isl_give isl_map *map_read_polylib(__isl_keep isl_stream *s)
{
  struct isl_token *tok;
  struct isl_token *tok2;
  int i, n;
  struct isl_map *map;
 
  tok = isl_stream_next_token(s);
  if (!tok) {
    isl_stream_error(s, NULL, "unexpected EOF");
    return NULL;
  }
  tok2 = isl_stream_next_token_on_same_line(s);
  if (tok2 && tok2->type == ISL_TOKEN_VALUE) {
    isl_stream_push_token(s, tok2);
    isl_stream_push_token(s, tok);
    return isl_map_from_basic_map(basic_map_read_polylib(s));
  }
  if (tok2) {
    isl_stream_error(s, tok2, "unexpected token");
    isl_stream_push_token(s, tok2);
    isl_stream_push_token(s, tok);
    return NULL;
  }
  n = isl_int_get_si(tok->u.v);
  isl_token_free(tok);
 
  isl_assert(s->ctx, n >= 1, return NULL);
 
  map = isl_map_from_basic_map(basic_map_read_polylib(s));
 
  for (i = 1; map && i < n; ++i)
    map = isl_map_union(map,
      isl_map_from_basic_map(basic_map_read_polylib(s)));
 
  return map;
}
 
static int optional_power(__isl_keep isl_stream *s)
{
  int pow;
  struct isl_token *tok;
 
  tok = isl_stream_next_token(s);
  if (!tok)
    return 1;
  if (tok->type != '^') {
    isl_stream_push_token(s, tok);
    return 1;
  }
  isl_token_free(tok);
  tok = isl_stream_next_token(s);
  if (!tok || tok->type != ISL_TOKEN_VALUE) {
    isl_stream_error(s, tok, "expecting exponent");
    if (tok)
      isl_stream_push_token(s, tok);
    return 1;
  }
  pow = isl_int_get_si(tok->u.v);
  isl_token_free(tok);
  return pow;
}
 
static __isl_give isl_pw_qpolynomial *read_term(__isl_keep isl_stream *s,
  __isl_keep isl_map *map, struct vars *v);
 
static __isl_give isl_pw_qpolynomial *read_factor(__isl_keep isl_stream *s,
  __isl_keep isl_map *map, struct vars *v)
{
  isl_pw_qpolynomial *pwqp;
  struct isl_token *tok;
 
  tok = next_token(s);
  if (!tok) {
    isl_stream_error(s, NULL, "unexpected EOF");
    return NULL;
  }
  if (tok->type == '(') {
    int pow;
 
    isl_token_free(tok);
    pwqp = read_term(s, map, v);
    if (!pwqp)
      return NULL;
    if (isl_stream_eat(s, ')'))
      goto error;
    pow = optional_power(s);
    pwqp = isl_pw_qpolynomial_pow(pwqp, pow);
  } else if (tok->type == ISL_TOKEN_VALUE) {
    struct isl_token *tok2;
    isl_qpolynomial *qp;
 
    tok2 = isl_stream_next_token(s);
    if (tok2 && tok2->type == '/') {
      isl_token_free(tok2);
      tok2 = next_token(s);
      if (!tok2 || tok2->type != ISL_TOKEN_VALUE) {
        isl_stream_error(s, tok2, "expected denominator");
        isl_token_free(tok);
        isl_token_free(tok2);
        return NULL;
      }
      qp = isl_qpolynomial_rat_cst_on_domain(isl_map_get_space(map),
                tok->u.v, tok2->u.v);
      isl_token_free(tok2);
    } else {
      isl_stream_push_token(s, tok2);
      qp = isl_qpolynomial_cst_on_domain(isl_map_get_space(map),
            tok->u.v);
    }
    isl_token_free(tok);
    pwqp = isl_pw_qpolynomial_from_qpolynomial(qp);
  } else if (tok->type == ISL_TOKEN_INFTY) {
    isl_qpolynomial *qp;
    isl_token_free(tok);
    qp = isl_qpolynomial_infty_on_domain(isl_map_get_space(map));
    pwqp = isl_pw_qpolynomial_from_qpolynomial(qp);
  } else if (tok->type == ISL_TOKEN_NAN) {
    isl_qpolynomial *qp;
    isl_token_free(tok);
    qp = isl_qpolynomial_nan_on_domain(isl_map_get_space(map));
    pwqp = isl_pw_qpolynomial_from_qpolynomial(qp);
  } else if (tok->type == ISL_TOKEN_IDENT) {
    int n = v->n;
    int pos = vars_pos(v, tok->u.s, -1);
    int pow;
    isl_qpolynomial *qp;
    if (pos < 0) {
      isl_token_free(tok);
      return NULL;
    }
    if (pos >= n) {
      vars_drop(v, v->n - n);
      isl_stream_error(s, tok, "unknown identifier");
      isl_token_free(tok);
      return NULL;
    }
    isl_token_free(tok);
    pow = optional_power(s);
    qp = isl_qpolynomial_var_pow_on_domain(isl_map_get_space(map), pos, pow);
    pwqp = isl_pw_qpolynomial_from_qpolynomial(qp);
  } else if (is_start_of_div(tok)) {
    isl_pw_aff *pwaff;
    int pow;
 
    isl_stream_push_token(s, tok);
    pwaff = accept_div(s, isl_map_get_space(map), v);
    pow = optional_power(s);
    pwqp = isl_pw_qpolynomial_from_pw_aff(pwaff);
    pwqp = isl_pw_qpolynomial_pow(pwqp, pow);
  } else if (tok->type == '-') {
    isl_token_free(tok);
    pwqp = read_factor(s, map, v);
    pwqp = isl_pw_qpolynomial_neg(pwqp);
  } else {
    isl_stream_error(s, tok, "unexpected isl_token");
    isl_stream_push_token(s, tok);
    return NULL;
  }
 
  if (isl_stream_eat_if_available(s, '*') ||
      isl_stream_next_token_is(s, ISL_TOKEN_IDENT)) {
    isl_pw_qpolynomial *pwqp2;
 
    pwqp2 = read_factor(s, map, v);
    pwqp = isl_pw_qpolynomial_mul(pwqp, pwqp2);
  }
 
  return pwqp;
error:
  isl_pw_qpolynomial_free(pwqp);
  return NULL;
}
 
static __isl_give isl_pw_qpolynomial *read_term(__isl_keep isl_stream *s,
  __isl_keep isl_map *map, struct vars *v)
{
  struct isl_token *tok;
  isl_pw_qpolynomial *pwqp;
 
  pwqp = read_factor(s, map, v);
 
  for (;;) {
    tok = next_token(s);
    if (!tok)
      return pwqp;
 
    if (tok->type == '+') {
      isl_pw_qpolynomial *pwqp2;
 
      isl_token_free(tok);
      pwqp2 = read_factor(s, map, v);
      pwqp = isl_pw_qpolynomial_add(pwqp, pwqp2);
    } else if (tok->type == '-') {
      isl_pw_qpolynomial *pwqp2;
 
      isl_token_free(tok);
      pwqp2 = read_factor(s, map, v);
      pwqp = isl_pw_qpolynomial_sub(pwqp, pwqp2);
    } else {
      isl_stream_push_token(s, tok);
      break;
    }
  }
 
  return pwqp;
}
 
static __isl_give isl_map *read_optional_formula(__isl_keep isl_stream *s,
  __isl_take isl_map *map, struct vars *v, int rational)
{
  struct isl_token *tok;
 
  tok = isl_stream_next_token(s);
  if (!tok) {
    isl_stream_error(s, NULL, "unexpected EOF");
    goto error;
  }
  if (tok->type == ':' ||
      (tok->type == ISL_TOKEN_OR && !strcmp(tok->u.s, "|"))) {
    isl_token_free(tok);
    map = read_formula(s, v, map, rational);
  } else
    isl_stream_push_token(s, tok);
 
  return map;
error:
  isl_map_free(map);
  return NULL;
}
 
static struct isl_obj obj_read_poly(__isl_keep isl_stream *s,
  __isl_take isl_map *map, struct vars *v, int n)
{
  struct isl_obj obj = { isl_obj_pw_qpolynomial, NULL };
  isl_pw_qpolynomial *pwqp;
  struct isl_set *set;
 
  pwqp = read_term(s, map, v);
  map = read_optional_formula(s, map, v, 0);
  set = isl_map_range(map);
 
  pwqp = isl_pw_qpolynomial_intersect_domain(pwqp, set);
 
  vars_drop(v, v->n - n);
 
  obj.v = pwqp;
  return obj;
}
 
static struct isl_obj obj_read_poly_or_fold(__isl_keep isl_stream *s,
  __isl_take isl_set *set, struct vars *v, int n)
{
  int min, max;
  struct isl_obj obj = { isl_obj_pw_qpolynomial_fold, NULL };
  isl_pw_qpolynomial *pwqp;
  isl_pw_qpolynomial_fold *pwf = NULL;
  enum isl_fold fold;
 
  max = isl_stream_eat_if_available(s, ISL_TOKEN_MAX);
  min = !max && isl_stream_eat_if_available(s, ISL_TOKEN_MIN);
  if (!min && !max)
    return obj_read_poly(s, set, v, n);
  fold = max ? isl_fold_max : isl_fold_min;
 
  if (isl_stream_eat(s, '('))
    goto error;
 
  pwqp = read_term(s, set, v);
  pwf = isl_pw_qpolynomial_fold_from_pw_qpolynomial(fold, pwqp);
 
  while (isl_stream_eat_if_available(s, ',')) {
    isl_pw_qpolynomial_fold *pwf_i;
    pwqp = read_term(s, set, v);
    pwf_i = isl_pw_qpolynomial_fold_from_pw_qpolynomial(fold, pwqp);
    pwf = isl_pw_qpolynomial_fold_fold(pwf, pwf_i);
  }
 
  if (isl_stream_eat(s, ')'))
    goto error;
 
  set = read_optional_formula(s, set, v, 0);
  pwf = isl_pw_qpolynomial_fold_intersect_domain(pwf, set);
 
  vars_drop(v, v->n - n);
 
  obj.v = pwf;
  return obj;
error:
  isl_set_free(set);
  isl_pw_qpolynomial_fold_free(pwf);
  obj.type = isl_obj_none;
  return obj;
}
 
static int is_rational(__isl_keep isl_stream *s)
{
  struct isl_token *tok;
 
  tok = isl_stream_next_token(s);
  if (!tok)
    return 0;
  if (tok->type == ISL_TOKEN_RAT && isl_stream_next_token_is(s, ':')) {
    isl_token_free(tok);
    isl_stream_eat(s, ':');
    return 1;
  }
 
  isl_stream_push_token(s, tok);
 
  return 0;
}
 
static struct isl_obj obj_read_body(__isl_keep isl_stream *s,
  __isl_take isl_map *map, struct vars *v)
{
  struct isl_token *tok;
  struct isl_obj obj = { isl_obj_set, NULL };
  int n = v->n;
  int rational;
 
  rational = is_rational(s);
  if (rational)
    map = isl_map_set_rational(map);
 
  if (isl_stream_next_token_is(s, ':')) {
    obj.type = isl_obj_set;
    obj.v = read_optional_formula(s, map, v, rational);
    return obj;
  }
 
  if (!next_is_tuple(s))
    return obj_read_poly_or_fold(s, map, v, n);
 
  map = read_map_tuple(s, map, isl_dim_in, v, 0);
  if (!map)
    goto error;
  tok = isl_stream_next_token(s);
  if (!tok)
    goto error;
  if (tok->type == ISL_TOKEN_TO) {
    obj.type = isl_obj_map;
    isl_token_free(tok);
    if (!next_is_tuple(s)) {
      isl_set *set = isl_map_domain(map);
      return obj_read_poly_or_fold(s, set, v, n);
    }
    map = read_map_tuple(s, map, isl_dim_out, v, 0);
    if (!map)
      goto error;
  } else {
    map = isl_map_domain(map);
    isl_stream_push_token(s, tok);
  }
 
  map = read_optional_formula(s, map, v, rational);
 
  vars_drop(v, v->n - n);
 
  obj.v = map;
  return obj;
error:
  isl_map_free(map);
  obj.type = isl_obj_none;
  return obj;
}
 
static struct isl_obj to_union(isl_ctx *ctx, struct isl_obj obj)
{
  if (obj.type == isl_obj_map) {
    obj.v = isl_union_map_from_map(obj.v);
    obj.type = isl_obj_union_map;
  } else if (obj.type == isl_obj_set) {
    obj.v = isl_union_set_from_set(obj.v);
    obj.type = isl_obj_union_set;
  } else if (obj.type == isl_obj_pw_qpolynomial) {
    obj.v = isl_union_pw_qpolynomial_from_pw_qpolynomial(obj.v);
    obj.type = isl_obj_union_pw_qpolynomial;
  } else if (obj.type == isl_obj_pw_qpolynomial_fold) {
    obj.v = isl_union_pw_qpolynomial_fold_from_pw_qpolynomial_fold(obj.v);
    obj.type = isl_obj_union_pw_qpolynomial_fold;
  } else
    isl_assert(ctx, 0, goto error);
  return obj;
error:
  obj.type->free(obj.v);
  obj.type = isl_obj_none;
  return obj;
}
 
static struct isl_obj obj_add(__isl_keep isl_stream *s,
  struct isl_obj obj1, struct isl_obj obj2)
{
  if (obj2.type == isl_obj_none || !obj2.v)
    goto error;
  if (obj1.type == isl_obj_set && obj2.type == isl_obj_union_set)
    obj1 = to_union(s->ctx, obj1);
  if (obj1.type == isl_obj_union_set && obj2.type == isl_obj_set)
    obj2 = to_union(s->ctx, obj2);
  if (obj1.type == isl_obj_map && obj2.type == isl_obj_union_map)
    obj1 = to_union(s->ctx, obj1);
  if (obj1.type == isl_obj_union_map && obj2.type == isl_obj_map)
    obj2 = to_union(s->ctx, obj2);
  if (obj1.type == isl_obj_pw_qpolynomial &&
      obj2.type == isl_obj_union_pw_qpolynomial)
    obj1 = to_union(s->ctx, obj1);
  if (obj1.type == isl_obj_union_pw_qpolynomial &&
      obj2.type == isl_obj_pw_qpolynomial)
    obj2 = to_union(s->ctx, obj2);
  if (obj1.type == isl_obj_pw_qpolynomial_fold &&
      obj2.type == isl_obj_union_pw_qpolynomial_fold)
    obj1 = to_union(s->ctx, obj1);
  if (obj1.type == isl_obj_union_pw_qpolynomial_fold &&
      obj2.type == isl_obj_pw_qpolynomial_fold)
    obj2 = to_union(s->ctx, obj2);
  if (obj1.type != obj2.type) {
    isl_stream_error(s, NULL,
        "attempt to combine incompatible objects");
    goto error;
  }
  if (!obj1.type->add)
    isl_die(s->ctx, isl_error_internal,
      "combination not supported on object type", goto error);
  if (obj1.type == isl_obj_map && !isl_map_has_equal_space(obj1.v, obj2.v)) {
    obj1 = to_union(s->ctx, obj1);
    obj2 = to_union(s->ctx, obj2);
  }
  if (obj1.type == isl_obj_set && !isl_set_has_equal_space(obj1.v, obj2.v)) {
    obj1 = to_union(s->ctx, obj1);
    obj2 = to_union(s->ctx, obj2);
  }
  if (obj1.type == isl_obj_pw_qpolynomial &&
      !isl_pw_qpolynomial_has_equal_space(obj1.v, obj2.v)) {
    obj1 = to_union(s->ctx, obj1);
    obj2 = to_union(s->ctx, obj2);
  }
  if (obj1.type == isl_obj_pw_qpolynomial_fold &&
      !isl_pw_qpolynomial_fold_has_equal_space(obj1.v, obj2.v)) {
    obj1 = to_union(s->ctx, obj1);
    obj2 = to_union(s->ctx, obj2);
  }
  obj1.v = obj1.type->add(obj1.v, obj2.v);
  return obj1;
error:
  obj1.type->free(obj1.v);
  obj2.type->free(obj2.v);
  obj1.type = isl_obj_none;
  obj1.v = NULL;
  return obj1;
}
 
/* Are the first two tokens on "s", "domain" (either as a string
 * or as an identifier) followed by ":"?
 */
static int next_is_domain_colon(__isl_keep isl_stream *s)
{
  struct isl_token *tok;
  char *name;
  int res;
 
  tok = isl_stream_next_token(s);
  if (!tok)
    return 0;
  if (tok->type != ISL_TOKEN_IDENT && tok->type != ISL_TOKEN_STRING) {
    isl_stream_push_token(s, tok);
    return 0;
  }
 
  name = isl_token_get_str(s->ctx, tok);
  res = !strcmp(name, "domain") && isl_stream_next_token_is(s, ':');
  free(name);
 
  isl_stream_push_token(s, tok);
 
  return res;
}
 
/* Do the first tokens on "s" look like a schedule?
 *
 * The root of a schedule is always a domain node, so the first thing
 * we expect in the stream is a domain key, i.e., "domain" followed
 * by ":".  If the schedule was printed in YAML flow style, then
 * we additionally expect a "{" to open the outer mapping.
 */
static int next_is_schedule(__isl_keep isl_stream *s)
{
  struct isl_token *tok;
  int is_schedule;
 
  tok = isl_stream_next_token(s);
  if (!tok)
    return 0;
  if (tok->type != '{') {
    isl_stream_push_token(s, tok);
    return next_is_domain_colon(s);
  }
 
  is_schedule = next_is_domain_colon(s);
  isl_stream_push_token(s, tok);
 
  return is_schedule;
}
 
/* Read an isl_schedule from "s" and store it in an isl_obj.
 */
static struct isl_obj schedule_read(__isl_keep isl_stream *s)
{
  struct isl_obj obj;
 
  obj.type = isl_obj_schedule;
  obj.v = isl_stream_read_schedule(s);
 
  return obj;
}
 
/* Read a disjunction of object bodies from "s".
 * That is, read the inside of the braces, but not the braces themselves.
 * "v" contains a description of the identifiers parsed so far.
 * "map" contains information about the parameters.
 */
static struct isl_obj obj_read_disjuncts(__isl_keep isl_stream *s,
  struct vars *v, __isl_keep isl_map *map)
{
  struct isl_obj obj = { isl_obj_set, NULL };
 
  if (isl_stream_next_token_is(s, '}')) {
    obj.type = isl_obj_union_set;
    obj.v = isl_union_set_empty(isl_map_get_space(map));
    return obj;
  }
 
  for (;;) {
    struct isl_obj o;
    o = obj_read_body(s, isl_map_copy(map), v);
    if (!obj.v)
      obj = o;
    else
      obj = obj_add(s, obj, o);
    if (obj.type == isl_obj_none || !obj.v)
      return obj;
    if (!isl_stream_eat_if_available(s, ';'))
      break;
    if (isl_stream_next_token_is(s, '}'))
      break;
  }
 
  return obj;
}
 
static struct isl_obj obj_read(__isl_keep isl_stream *s)
{
  isl_map *map = NULL;
  struct isl_token *tok;
  struct vars *v = NULL;
  struct isl_obj obj = { isl_obj_set, NULL };
 
  if (next_is_schedule(s))
    return schedule_read(s);
 
  tok = next_token(s);
  if (!tok) {
    isl_stream_error(s, NULL, "unexpected EOF");
    goto error;
  }
  if (tok->type == ISL_TOKEN_VALUE) {
    struct isl_token *tok2;
    struct isl_map *map;
 
    tok2 = isl_stream_next_token(s);
    if (!tok2 || tok2->type != ISL_TOKEN_VALUE ||
        isl_int_is_neg(tok2->u.v)) {
      if (tok2)
        isl_stream_push_token(s, tok2);
      obj.type = isl_obj_val;
      obj.v = isl_val_int_from_isl_int(s->ctx, tok->u.v);
      isl_token_free(tok);
      return obj;
    }
    isl_stream_push_token(s, tok2);
    isl_stream_push_token(s, tok);
    map = map_read_polylib(s);
    if (!map)
      goto error;
    if (isl_map_may_be_set(map))
      obj.v = isl_map_range(map);
    else {
      obj.type = isl_obj_map;
      obj.v = map;
    }
    return obj;
  }
  v = vars_new(s->ctx);
  if (!v) {
    isl_stream_push_token(s, tok);
    goto error;
  }
  map = isl_map_universe(isl_space_params_alloc(s->ctx, 0));
  if (tok->type == '[') {
    isl_stream_push_token(s, tok);
    map = read_map_tuple(s, map, isl_dim_param, v, 0);
    if (!map)
      goto error;
    tok = isl_stream_next_token(s);
    if (!tok || tok->type != ISL_TOKEN_TO) {
      isl_stream_error(s, tok, "expecting '->'");
      if (tok)
        isl_stream_push_token(s, tok);
      goto error;
    }
    isl_token_free(tok);
    tok = isl_stream_next_token(s);
  }
  if (!tok || tok->type != '{') {
    isl_stream_error(s, tok, "expecting '{'");
    if (tok)
      isl_stream_push_token(s, tok);
    goto error;
  }
  isl_token_free(tok);
 
  tok = isl_stream_next_token(s);
  if (!tok)
    ;
  else if (tok->type == ISL_TOKEN_IDENT && !strcmp(tok->u.s, "Sym")) {
    isl_token_free(tok);
    if (isl_stream_eat(s, '='))
      goto error;
    map = read_map_tuple(s, map, isl_dim_param, v, 1);
    if (!map)
      goto error;
  } else
    isl_stream_push_token(s, tok);
 
  obj = obj_read_disjuncts(s, v, map);
  if (obj.type == isl_obj_none || !obj.v)
    goto error;
 
  tok = isl_stream_next_token(s);
  if (tok && tok->type == '}') {
    isl_token_free(tok);
  } else {
    isl_stream_error(s, tok, "unexpected isl_token");
    if (tok)
      isl_token_free(tok);
    goto error;
  }
 
  vars_free(v);
  isl_map_free(map);
 
  return obj;
error:
  isl_map_free(map);
  obj.type->free(obj.v);
  if (v)
    vars_free(v);
  obj.v = NULL;
  return obj;
}
 
struct isl_obj isl_stream_read_obj(__isl_keep isl_stream *s)
{
  return obj_read(s);
}
 
__isl_give isl_map *isl_stream_read_map(__isl_keep isl_stream *s)
{
  struct isl_obj obj;
 
  obj = obj_read(s);
  if (obj.v)
    isl_assert(s->ctx, obj.type == isl_obj_map ||
           obj.type == isl_obj_set, goto error);
  
  if (obj.type == isl_obj_set)
    obj.v = isl_map_from_range(obj.v);
 
  return obj.v;
error:
  obj.type->free(obj.v);
  return NULL;
}
 
__isl_give isl_set *isl_stream_read_set(__isl_keep isl_stream *s)
{
  struct isl_obj obj;
 
  obj = obj_read(s);
  if (obj.v) {
    if (obj.type == isl_obj_map && isl_map_may_be_set(obj.v)) {
      obj.v = isl_map_range(obj.v);
      obj.type = isl_obj_set;
    }
    isl_assert(s->ctx, obj.type == isl_obj_set, goto error);
  }
 
  return obj.v;
error:
  obj.type->free(obj.v);
  return NULL;
}
 
__isl_give isl_union_map *isl_stream_read_union_map(__isl_keep isl_stream *s)
{
  struct isl_obj obj;
 
  obj = obj_read(s);
  if (obj.type == isl_obj_map) {
    obj.type = isl_obj_union_map;
    obj.v = isl_union_map_from_map(obj.v);
  }
  if (obj.type == isl_obj_set) {
    obj.type = isl_obj_union_set;
    obj.v = isl_union_set_from_set(obj.v);
  }
  if (obj.v && obj.type == isl_obj_union_set &&
      isl_union_set_is_empty(obj.v))
    obj.type = isl_obj_union_map;
  if (obj.v && obj.type != isl_obj_union_map)
    isl_die(s->ctx, isl_error_invalid, "invalid input", goto error);
 
  return obj.v;
error:
  obj.type->free(obj.v);
  return NULL;
}
 
/* Extract an isl_union_set from "obj".
 * This only works if the object was detected as either a set
 * (in which case it is converted to a union set) or a union set.
 */
static __isl_give isl_union_set *extract_union_set(isl_ctx *ctx,
  struct isl_obj obj)
{
  if (obj.type == isl_obj_set) {
    obj.type = isl_obj_union_set;
    obj.v = isl_union_set_from_set(obj.v);
  }
  if (obj.v)
    isl_assert(ctx, obj.type == isl_obj_union_set, goto error);
 
  return obj.v;
error:
  obj.type->free(obj.v);
  return NULL;
}
 
/* Read an isl_union_set from "s".
 * First read a generic object and then try and extract
 * an isl_union_set from that.
 */
__isl_give isl_union_set *isl_stream_read_union_set(__isl_keep isl_stream *s)
{
  struct isl_obj obj;
 
  obj = obj_read(s);
  return extract_union_set(s->ctx, obj);
}
 
static __isl_give isl_basic_map *isl_stream_read_basic_map(
  __isl_keep isl_stream *s)
{
  struct isl_obj obj;
  struct isl_map *map;
  struct isl_basic_map *bmap;
 
  obj = obj_read(s);
  if (obj.v && (obj.type != isl_obj_map && obj.type != isl_obj_set))
    isl_die(s->ctx, isl_error_invalid, "not a (basic) set or map",
      goto error);
  map = obj.v;
  if (!map)
    return NULL;
 
  if (map->n > 1)
    isl_die(s->ctx, isl_error_invalid,
      "set or map description involves "
      "more than one disjunct", goto error);
 
  if (map->n == 0)
    bmap = isl_basic_map_empty(isl_map_get_space(map));
  else
    bmap = isl_basic_map_copy(map->p[0]);
 
  isl_map_free(map);
 
  return bmap;
error:
  obj.type->free(obj.v);
  return NULL;
}
 
/* Read an isl_basic_set object from "s".
 */
__isl_give isl_basic_set *isl_stream_read_basic_set(__isl_keep isl_stream *s)
{
  isl_basic_map *bmap;
  bmap = isl_stream_read_basic_map(s);
  if (!bmap)
    return NULL;
  if (!isl_basic_map_may_be_set(bmap))
    isl_die(s->ctx, isl_error_invalid,
      "input is not a set", goto error);
  return isl_basic_map_range(bmap);
error:
  isl_basic_map_free(bmap);
  return NULL;
}
 
__isl_give isl_basic_map *isl_basic_map_read_from_file(isl_ctx *ctx,
  FILE *input)
{
  struct isl_basic_map *bmap;
  isl_stream *s = isl_stream_new_file(ctx, input);
  if (!s)
    return NULL;
  bmap = isl_stream_read_basic_map(s);
  isl_stream_free(s);
  return bmap;
}
 
__isl_give isl_basic_set *isl_basic_set_read_from_file(isl_ctx *ctx,
  FILE *input)
{
  isl_basic_set *bset;
  isl_stream *s = isl_stream_new_file(ctx, input);
  if (!s)
    return NULL;
  bset = isl_stream_read_basic_set(s);
  isl_stream_free(s);
  return bset;
}
 
#undef TYPE_BASE
#define TYPE_BASE basic_map
#include "isl_read_from_str_templ.c"
 
#undef TYPE_BASE
#define TYPE_BASE basic_set
#include "isl_read_from_str_templ.c"
 
__isl_give isl_map *isl_map_read_from_file(struct isl_ctx *ctx,
  FILE *input)
{
  struct isl_map *map;
  isl_stream *s = isl_stream_new_file(ctx, input);
  if (!s)
    return NULL;
  map = isl_stream_read_map(s);
  isl_stream_free(s);
  return map;
}
 
#undef TYPE_BASE
#define TYPE_BASE map
#include "isl_read_from_str_templ.c"
 
__isl_give isl_set *isl_set_read_from_file(struct isl_ctx *ctx,
  FILE *input)
{
  isl_set *set;
  isl_stream *s = isl_stream_new_file(ctx, input);
  if (!s)
    return NULL;
  set = isl_stream_read_set(s);
  isl_stream_free(s);
  return set;
}
 
#undef TYPE_BASE
#define TYPE_BASE set
#include "isl_read_from_str_templ.c"
 
__isl_give isl_union_map *isl_union_map_read_from_file(isl_ctx *ctx,
  FILE *input)
{
  isl_union_map *umap;
  isl_stream *s = isl_stream_new_file(ctx, input);
  if (!s)
    return NULL;
  umap = isl_stream_read_union_map(s);
  isl_stream_free(s);
  return umap;
}
 
#undef TYPE_BASE
#define TYPE_BASE union_map
#include "isl_read_from_str_templ.c"
 
__isl_give isl_union_set *isl_union_set_read_from_file(isl_ctx *ctx,
  FILE *input)
{
  isl_union_set *uset;
  isl_stream *s = isl_stream_new_file(ctx, input);
  if (!s)
    return NULL;
  uset = isl_stream_read_union_set(s);
  isl_stream_free(s);
  return uset;
}
 
#undef TYPE_BASE
#define TYPE_BASE union_set
#include "isl_read_from_str_templ.c"
 
static __isl_give isl_vec *isl_vec_read_polylib(__isl_keep isl_stream *s)
{
  struct isl_vec *vec = NULL;
  struct isl_token *tok;
  unsigned size;
  int j;
 
  tok = isl_stream_next_token(s);
  if (!tok || tok->type != ISL_TOKEN_VALUE) {
    isl_stream_error(s, tok, "expecting vector length");
    goto error;
  }
 
  size = isl_int_get_si(tok->u.v);
  isl_token_free(tok);
 
  vec = isl_vec_alloc(s->ctx, size);
 
  for (j = 0; j < size; ++j) {
    tok = next_signed_value(s, "expecting constant value");
    if (!tok)
      goto error;
    isl_int_set(vec->el[j], tok->u.v);
    isl_token_free(tok);
  }
 
  return vec;
error:
  isl_token_free(tok);
  isl_vec_free(vec);
  return NULL;
}
 
static __isl_give isl_vec *vec_read(__isl_keep isl_stream *s)
{
  return isl_vec_read_polylib(s);
}
 
__isl_give isl_vec *isl_vec_read_from_file(isl_ctx *ctx, FILE *input)
{
  isl_vec *v;
  isl_stream *s = isl_stream_new_file(ctx, input);
  if (!s)
    return NULL;
  v = vec_read(s);
  isl_stream_free(s);
  return v;
}
 
__isl_give isl_pw_qpolynomial *isl_stream_read_pw_qpolynomial(
  __isl_keep isl_stream *s)
{
  struct isl_obj obj;
 
  obj = obj_read(s);
  if (obj.v)
    isl_assert(s->ctx, obj.type == isl_obj_pw_qpolynomial,
         goto error);
 
  return obj.v;
error:
  obj.type->free(obj.v);
  return NULL;
}
 
#undef TYPE_BASE
#define TYPE_BASE pw_qpolynomial
#include "isl_read_from_str_templ.c"
 
__isl_give isl_pw_qpolynomial *isl_pw_qpolynomial_read_from_file(isl_ctx *ctx,
    FILE *input)
{
  isl_pw_qpolynomial *pwqp;
  isl_stream *s = isl_stream_new_file(ctx, input);
  if (!s)
    return NULL;
  pwqp = isl_stream_read_pw_qpolynomial(s);
  isl_stream_free(s);
  return pwqp;
}
 
/* Read an isl_pw_qpolynomial_fold from "s".
 * First read a generic object and
 * then check that it is an isl_pw_qpolynomial_fold.
 */
__isl_give isl_pw_qpolynomial_fold *isl_stream_read_pw_qpolynomial_fold(
  __isl_keep isl_stream *s)
{
  struct isl_obj obj;
 
  obj = obj_read(s);
  if (obj.v && obj.type != isl_obj_pw_qpolynomial_fold)
    isl_die(s->ctx, isl_error_invalid, "invalid input", goto error);
 
  return obj.v;
error:
  obj.type->free(obj.v);
  return NULL;
}
 
#undef TYPE_BASE
#define TYPE_BASE pw_qpolynomial_fold
#include "isl_read_from_str_templ.c"
 
/* Is the next token an identifier not in "v"?
 */
static int next_is_fresh_ident(__isl_keep isl_stream *s, struct vars *v)
{
  int n = v->n;
  int fresh;
  struct isl_token *tok;
 
  tok = isl_stream_next_token(s);
  if (!tok)
    return 0;
  fresh = tok->type == ISL_TOKEN_IDENT && vars_pos(v, tok->u.s, -1) >= n;
  isl_stream_push_token(s, tok);
 
  vars_drop(v, v->n - n);
 
  return fresh;
}
 
/* First read the domain of the affine expression, which may be
 * a parameter space or a set.
 * The tricky part is that we don't know if the domain is a set or not,
 * so when we are trying to read the domain, we may actually be reading
 * the affine expression itself (defined on a parameter domains)
 * If the tuple we are reading is named, we assume it's the domain.
 * Also, if inside the tuple, the first thing we find is a nested tuple
 * or a new identifier, we again assume it's the domain.
 * Finally, if the tuple is empty, then it must be the domain
 * since it does not contain an affine expression.
 * Otherwise, we assume we are reading an affine expression.
 */
static __isl_give isl_set *read_aff_domain(__isl_keep isl_stream *s,
  __isl_take isl_set *dom, struct vars *v)
{
  struct isl_token *tok, *tok2;
  int is_empty;
 
  tok = isl_stream_next_token(s);
  if (tok && (tok->type == ISL_TOKEN_IDENT || tok->is_keyword)) {
    isl_stream_push_token(s, tok);
    return read_map_tuple(s, dom, isl_dim_set, v, 0);
  }
  if (!tok || tok->type != '[') {
    isl_stream_error(s, tok, "expecting '['");
    goto error;
  }
  tok2 = isl_stream_next_token(s);
  is_empty = tok2 && tok2->type == ']';
  if (tok2)
    isl_stream_push_token(s, tok2);
  if (is_empty || next_is_tuple(s) || next_is_fresh_ident(s, v)) {
    isl_stream_push_token(s, tok);
    dom = read_map_tuple(s, dom, isl_dim_set, v, 0);
  } else
    isl_stream_push_token(s, tok);
 
  return dom;
error:
  if (tok)
    isl_stream_push_token(s, tok);
  isl_set_free(dom);
  return NULL;
}
 
/* Read an affine expression from "s".
 */
__isl_give isl_aff *isl_stream_read_aff(__isl_keep isl_stream *s)
{
  isl_aff *aff;
  isl_multi_aff *ma;
  isl_size dim;
 
  ma = isl_stream_read_multi_aff(s);
  dim = isl_multi_aff_dim(ma, isl_dim_out);
  if (dim < 0)
    goto error;
  if (dim != 1)
    isl_die(s->ctx, isl_error_invalid,
      "expecting single affine expression",
      goto error);
 
  aff = isl_multi_aff_get_aff(ma, 0);
  isl_multi_aff_free(ma);
  return aff;
error:
  isl_multi_aff_free(ma);
  return NULL;
}
 
/* Read a piecewise affine expression from "s" with domain (space) "dom".
 */
static __isl_give isl_pw_aff *read_pw_aff_with_dom(__isl_keep isl_stream *s,
  __isl_take isl_set *dom, struct vars *v)
{
  isl_pw_aff *pwaff = NULL;
 
  if (!isl_set_is_params(dom) && isl_stream_eat(s, ISL_TOKEN_TO))
    goto error;
 
  if (isl_stream_eat(s, '['))
    goto error;
 
  pwaff = accept_affine(s, isl_set_get_space(dom), v);
 
  if (isl_stream_eat(s, ']'))
    goto error;
 
  dom = read_optional_formula(s, dom, v, 0);
  pwaff = isl_pw_aff_intersect_domain(pwaff, dom);
 
  return pwaff;
error:
  isl_set_free(dom);
  isl_pw_aff_free(pwaff);
  return NULL;
}
 
/* Read an affine expression, together with optional constraints
 * on the domain from "s".  "dom" represents the initial constraints
 * on the parameter domain.
 * "v" contains a description of the identifiers parsed so far.
 */
static __isl_give isl_pw_aff *read_conditional_aff(__isl_keep isl_stream *s,
  __isl_take isl_set *dom, struct vars *v)
{
  isl_set *aff_dom;
  isl_pw_aff *pa;
  int n;
 
  n = v->n;
  aff_dom = read_aff_domain(s, dom, v);
  pa = read_pw_aff_with_dom(s, aff_dom, v);
  vars_drop(v, v->n - n);
 
  return pa;
}
 
#undef BASE
#define BASE  aff
#include "isl_stream_read_pw_with_params_templ.c"
 
#undef TYPE_BASE
#define TYPE_BASE aff
#include "isl_read_from_str_templ.c"
 
#undef TYPE_BASE
#define TYPE_BASE pw_aff
#include "isl_stream_read_with_params_templ.c"
#include "isl_read_from_str_templ.c"
 
/* Given that "pa" is the element at position "pos" of a tuple
 * returned by read_tuple, check that it does not involve any
 * output/set dimensions (appearing at the "n" positions starting at "first"),
 * remove those from the domain and replace the domain space
 * with "domain_space".
 *
 * In particular, the result of read_tuple is of the form
 * [input, output] -> [output], with anonymous domain.
 * The function read_tuple accepts tuples where some output or
 * set dimensions are defined in terms of other output or set dimensions
 * since this function is also used to read maps.  As a special case,
 * read_tuple also accepts dimensions that are defined in terms of themselves
 * (i.e., that are not defined).
 * These cases are not allowed here.
 */
static __isl_give isl_pw_aff *separate_tuple_entry(__isl_take isl_pw_aff *pa,
  int pos, unsigned first, unsigned n, __isl_take isl_space *domain_space)
{
  isl_bool involves;
 
  involves = isl_pw_aff_involves_dims(pa, isl_dim_in, first, pos + 1);
  if (involves < 0) {
    pa =  isl_pw_aff_free(pa);
  } else if (involves) {
    isl_die(isl_pw_aff_get_ctx(pa), isl_error_invalid,
      "not an affine expression",
      pa = isl_pw_aff_free(pa));
  }
  pa = isl_pw_aff_drop_dims(pa, isl_dim_in, first, n);
  pa = isl_pw_aff_reset_domain_space(pa, domain_space);
 
  return pa;
}
 
/* Set entry "pos" of "mpa" to the corresponding entry in "tuple",
 * as obtained from read_tuple().
 * The "n" output dimensions also appear among the input dimensions
 * at position "first".
 *
 * The entry is not allowed to depend on any (other) output dimensions.
 */
static __isl_give isl_multi_pw_aff *isl_multi_pw_aff_set_tuple_entry(
  __isl_take isl_multi_pw_aff *mpa, __isl_take isl_pw_aff *tuple_el,
  int pos, unsigned first, unsigned n)
{
  isl_space *space;
  isl_pw_aff *pa;
 
  space = isl_multi_pw_aff_get_domain_space(mpa);
  pa = separate_tuple_entry(tuple_el, pos, first, n, space);
  return isl_multi_pw_aff_set_pw_aff(mpa, pos, pa);
}
 
#undef BASE
#define BASE pw_aff
 
#include <isl_multi_from_tuple_templ.c>
 
/* Read a tuple of piecewise affine expressions,
 * including optional constraints on the domain from "s".
 * "dom" represents the initial constraints on the domain.
 *
 * The input format is similar to that of a map, except that any conditions
 * on the domains should be specified inside the tuple since each
 * piecewise affine expression may have a different domain.
 * However, additional, shared conditions can also be specified.
 * This is especially useful for setting the explicit domain
 * of a zero-dimensional isl_multi_pw_aff.
 *
 * The isl_multi_pw_aff may live in either a set or a map space.
 * First read the first tuple and check if it is followed by a "->".
 * If so, convert the tuple into the domain of the isl_multi_pw_aff and
 * read in the next tuple.  This tuple (or the first tuple if it was
 * not followed by a "->") is then converted into an isl_multi_pw_aff
 * through a call to isl_multi_pw_aff_from_tuple.
 * The domain of the result is intersected with the domain.
 *
 * Note that the last tuple may introduce new identifiers,
 * but these cannot be referenced in the description of the domain.
 */
static __isl_give isl_multi_pw_aff *read_conditional_multi_pw_aff(
  __isl_keep isl_stream *s, __isl_take isl_set *dom, struct vars *v)
{
  isl_multi_pw_aff *tuple;
  isl_multi_pw_aff *mpa;
  int n = v->n;
  int n_dom;
 
  n_dom = v->n;
  tuple = read_tuple(s, v, 0, 0);
  if (!tuple)
    goto error;
  if (isl_stream_eat_if_available(s, ISL_TOKEN_TO)) {
    isl_map *map = map_from_tuple(tuple, dom, isl_dim_in, v, 0);
    dom = isl_map_domain(map);
    n_dom = v->n;
    tuple = read_tuple(s, v, 0, 0);
    if (!tuple)
      goto error;
  }
  mpa = isl_multi_pw_aff_from_tuple(isl_set_get_space(dom), tuple);
  if (!mpa)
    dom = isl_set_free(dom);
 
  vars_drop(v, v->n - n_dom);
  dom = read_optional_formula(s, dom, v, 0);
 
  vars_drop(v, v->n - n);
 
  mpa = isl_multi_pw_aff_intersect_domain(mpa, dom);
 
  return mpa;
error:
  isl_set_free(dom);
  return NULL;
}
 
/* Read a tuple of affine expressions, together with optional constraints
 * on the domain from "s".  "dom" represents the initial constraints
 * on the domain.
 *
 * Read a tuple of piecewise affine expressions with optional constraints and
 * convert the result to an isl_pw_multi_aff on the shared domain.
 */
static __isl_give isl_pw_multi_aff *read_conditional_multi_aff(
  __isl_keep isl_stream *s, __isl_take isl_set *dom, struct vars *v)
{
  isl_multi_pw_aff *mpa;
 
  mpa = read_conditional_multi_pw_aff(s, dom, v);
  return isl_pw_multi_aff_from_multi_pw_aff(mpa);
}
 
/* Read an isl_union_pw_multi_aff from "s" with parameter domain "dom".
 * "v" contains a description of the identifiers parsed so far.
 *
 * In particular, read a sequence
 * of zero or more tuples of affine expressions with optional conditions and
 * add them up.
 */
static __isl_give isl_union_pw_multi_aff *
isl_stream_read_with_params_union_pw_multi_aff(__isl_keep isl_stream *s,
  __isl_keep isl_set *dom, struct vars *v)
{
  isl_union_pw_multi_aff *upma;
 
  upma = isl_union_pw_multi_aff_empty(isl_set_get_space(dom));
 
  do {
    isl_pw_multi_aff *pma;
    isl_union_pw_multi_aff *upma2;
 
    if (isl_stream_next_token_is(s, '}'))
      break;
 
    pma = read_conditional_multi_aff(s, isl_set_copy(dom), v);
    upma2 = isl_union_pw_multi_aff_from_pw_multi_aff(pma);
    upma = isl_union_pw_multi_aff_union_add(upma, upma2);
    if (!upma)
      return NULL;
  } while (isl_stream_eat_if_available(s, ';'));
 
  return upma;
}
 
#undef BASE
#define BASE  multi_aff
#include "isl_stream_read_pw_with_params_templ.c"
 
#undef TYPE_BASE
#define TYPE_BASE pw_multi_aff
#include "isl_stream_read_with_params_templ.c"
#include "isl_read_from_str_templ.c"
 
#undef TYPE_BASE
#define TYPE_BASE union_pw_multi_aff
#include "isl_stream_read_with_params_templ.c"
#include "isl_read_from_str_templ.c"
 
#undef BASE
#define BASE val
 
#include <isl_multi_read_no_explicit_domain_templ.c>
 
#undef BASE
#define BASE id
 
#include <isl_multi_read_no_explicit_domain_templ.c>
 
/* Set entry "pos" of "ma" to the corresponding entry in "tuple",
 * as obtained from read_tuple().
 * The "n" output dimensions also appear among the input dimensions
 * at position "first".
 *
 * The entry is not allowed to depend on any (other) output dimensions.
 */
static __isl_give isl_multi_aff *isl_multi_aff_set_tuple_entry(
  __isl_take isl_multi_aff *ma, __isl_take isl_pw_aff *tuple_el,
  int pos, unsigned first, unsigned n)
{
  isl_space *space;
  isl_pw_aff *pa;
  isl_aff *aff;
 
  space = isl_multi_aff_get_domain_space(ma);
  pa = separate_tuple_entry(tuple_el, pos, first, n, space);
  aff = isl_pw_aff_as_aff(pa);
  return isl_multi_aff_set_aff(ma, pos, aff);
}
 
#undef BASE
#define BASE aff
 
#include <isl_multi_from_tuple_templ.c>
 
/* Read a multi-affine expression from "s".
 * If the multi-affine expression has a domain, then the tuple
 * representing this domain cannot involve any affine expressions.
 * The tuple representing the actual expressions needs to consist
 * of only affine expressions.
 */
__isl_give isl_multi_aff *isl_stream_read_multi_aff(__isl_keep isl_stream *s)
{
  struct vars *v;
  isl_multi_pw_aff *tuple = NULL;
  isl_space *dom_space = NULL;
  isl_multi_aff *ma = NULL;
 
  v = vars_new(s->ctx);
  if (!v)
    return NULL;
 
  dom_space = read_params(s, v);
  if (!dom_space)
    goto error;
  if (isl_stream_eat(s, '{'))
    goto error;
 
  tuple = read_tuple(s, v, 0, 0);
  if (!tuple)
    goto error;
  if (isl_stream_eat_if_available(s, ISL_TOKEN_TO)) {
    isl_space *space;
    isl_bool has_expr;
 
    has_expr = tuple_has_expr(tuple);
    if (has_expr < 0)
      goto error;
    if (has_expr)
      isl_die(s->ctx, isl_error_invalid,
        "expecting universe domain", goto error);
    space = isl_space_range(isl_multi_pw_aff_get_space(tuple));
    dom_space = isl_space_align_params(space, dom_space);
    isl_multi_pw_aff_free(tuple);
    tuple = read_tuple(s, v, 0, 0);
    if (!tuple)
      goto error;
  }
 
  if (isl_stream_eat(s, '}'))
    goto error;
 
  ma = isl_multi_aff_from_tuple(dom_space, tuple);
 
  vars_free(v);
  return ma;
error:
  isl_multi_pw_aff_free(tuple);
  vars_free(v);
  isl_space_free(dom_space);
  isl_multi_aff_free(ma);
  return NULL;
}
 
#undef TYPE_BASE
#define TYPE_BASE multi_aff
#include "isl_read_from_str_templ.c"
 
/* Read an isl_multi_pw_aff from "s" with parameter domain "dom"..
 * "v" contains a description of the identifiers parsed so far.
 */
static __isl_give isl_multi_pw_aff *isl_stream_read_with_params_multi_pw_aff(
  __isl_keep isl_stream *s, __isl_keep isl_set *dom, struct vars *v)
{
  return read_conditional_multi_pw_aff(s, isl_set_copy(dom), v);
}
 
#undef TYPE_BASE
#define TYPE_BASE multi_pw_aff
#include "isl_stream_read_with_params_templ.c"
#include "isl_read_from_str_templ.c"
 
/* Return an empty isl_union_pw_aff with parameter domain "dom".
 */
static __isl_give isl_union_pw_aff *empty_union_pw_aff_with_dom(
  __isl_take isl_set *dom)
{
  isl_space *space;
 
  space = isl_set_get_space(dom);
  isl_set_free(dom);
  return isl_union_pw_aff_empty_space(space);
}
 
/* Read the body of an isl_union_pw_aff from "s" with parameter domain "dom".
 */
static __isl_give isl_union_pw_aff *read_union_pw_aff_with_dom(
  __isl_keep isl_stream *s, __isl_take isl_set *dom, struct vars *v)
{
  isl_pw_aff *pa;
  isl_union_pw_aff *upa = NULL;
  isl_set *aff_dom;
  int n;
 
  if (isl_stream_next_token_is(s, '}'))
    return empty_union_pw_aff_with_dom(dom);
 
  n = v->n;
  aff_dom = read_aff_domain(s, isl_set_copy(dom), v);
  pa = read_pw_aff_with_dom(s, aff_dom, v);
  vars_drop(v, v->n - n);
 
  upa = isl_union_pw_aff_from_pw_aff(pa);
 
  while (isl_stream_eat_if_available(s, ';')) {
    isl_pw_aff *pa_i;
    isl_union_pw_aff *upa_i;
 
    n = v->n;
    aff_dom = read_aff_domain(s, isl_set_copy(dom), v);
    pa_i = read_pw_aff_with_dom(s, aff_dom, v);
    vars_drop(v, v->n - n);
 
    upa_i = isl_union_pw_aff_from_pw_aff(pa_i);
    upa = isl_union_pw_aff_union_add(upa, upa_i);
  }
 
  isl_set_free(dom);
  return upa;
}
 
/* Read an isl_union_pw_aff from "s" with parameter domain "dom".
 * "v" contains a description of the identifiers parsed so far.
 */
static __isl_give isl_union_pw_aff *isl_stream_read_with_params_union_pw_aff(
  __isl_keep isl_stream *s, __isl_keep isl_set *dom, struct vars *v)
{
  return read_union_pw_aff_with_dom(s, isl_set_copy(dom), v);
}
 
#undef TYPE_BASE
#define TYPE_BASE union_pw_aff
#include "isl_stream_read_with_params_templ.c"
#include "isl_read_from_str_templ.c"
 
/* This function is called for each element in a tuple inside
 * isl_stream_read_multi_union_pw_aff.
 *
 * Read a '{', the union piecewise affine expression body and a '}' and
 * add the isl_union_pw_aff to *list.
 */
static __isl_give isl_space *read_union_pw_aff_el(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_space *space, int rational, void *user)
{
  isl_set *dom;
  isl_union_pw_aff *upa;
  isl_union_pw_aff_list **list = (isl_union_pw_aff_list **) user;
 
  dom = isl_set_universe(isl_space_params(isl_space_copy(space)));
  if (isl_stream_eat(s, '{'))
    goto error;
  upa = read_union_pw_aff_with_dom(s, dom, v);
  *list = isl_union_pw_aff_list_add(*list, upa);
  if (isl_stream_eat(s, '}'))
    return isl_space_free(space);
  if (!*list)
    return isl_space_free(space);
  return space;
error:
  isl_set_free(dom);
  return isl_space_free(space);
}
 
/* Do the next tokens in "s" correspond to an empty tuple?
 * In particular, does the stream start with a '[', followed by a ']',
 * not followed by a "->"?
 */
static int next_is_empty_tuple(__isl_keep isl_stream *s)
{
  struct isl_token *tok, *tok2, *tok3;
  int is_empty_tuple = 0;
 
  tok = isl_stream_next_token(s);
  if (!tok)
    return 0;
  if (tok->type != '[') {
    isl_stream_push_token(s, tok);
    return 0;
  }
 
  tok2 = isl_stream_next_token(s);
  if (tok2 && tok2->type == ']') {
    tok3 = isl_stream_next_token(s);
    is_empty_tuple = !tok || tok->type != ISL_TOKEN_TO;
    if (tok3)
      isl_stream_push_token(s, tok3);
  }
  if (tok2)
    isl_stream_push_token(s, tok2);
  isl_stream_push_token(s, tok);
 
  return is_empty_tuple;
}
 
/* Do the next tokens in "s" correspond to a tuple of parameters?
 * In particular, does the stream start with a '[' that is not
 * followed by a '{' or a nested tuple?
 */
static int next_is_param_tuple(__isl_keep isl_stream *s)
{
  struct isl_token *tok, *tok2;
  int is_tuple;
 
  tok = isl_stream_next_token(s);
  if (!tok)
    return 0;
  if (tok->type != '[' || next_is_tuple(s)) {
    isl_stream_push_token(s, tok);
    return 0;
  }
 
  tok2 = isl_stream_next_token(s);
  is_tuple = tok2 && tok2->type != '{';
  if (tok2)
    isl_stream_push_token(s, tok2);
  isl_stream_push_token(s, tok);
 
  return is_tuple;
}
 
/* Read the core of a body of an isl_multi_union_pw_aff from "s",
 * i.e., everything except the parameter specification and
 * without shared domain constraints.
 * "v" contains a description of the identifiers parsed so far.
 * The parameters, if any, are specified by "space".
 *
 * The body is of the form
 *
 *  [{ [..] : ... ; [..] : ... }, { [..] : ... ; [..] : ... }]
 *
 * Read the tuple, collecting the individual isl_union_pw_aff
 * elements in a list and construct the result from the tuple space and
 * the list.
 */
static __isl_give isl_multi_union_pw_aff *read_multi_union_pw_aff_body_core(
  __isl_keep isl_stream *s, struct vars *v, __isl_take isl_space *space)
{
  isl_union_pw_aff_list *list;
  isl_multi_union_pw_aff *mupa;
 
  list = isl_union_pw_aff_list_alloc(s->ctx, 0);
  space = read_tuple_space(s, v, space, 1, 0,
        &read_union_pw_aff_el, &list);
  mupa = isl_multi_union_pw_aff_from_union_pw_aff_list(space, list);
 
  return mupa;
}
 
/* Read the body of an isl_union_set from "s",
 * i.e., everything except the parameter specification.
 * "v" contains a description of the identifiers parsed so far.
 * The parameters, if any, are specified by "space".
 *
 * First read a generic disjunction of object bodies and then try and extract
 * an isl_union_set from that.
 */
static __isl_give isl_union_set *read_union_set_body(__isl_keep isl_stream *s,
  struct vars *v, __isl_take isl_space *space)
{
  struct isl_obj obj = { isl_obj_set, NULL };
  isl_map *map;
 
  map = isl_set_universe(space);
  if (isl_stream_eat(s, '{') < 0)
    goto error;
  obj = obj_read_disjuncts(s, v, map);
  if (isl_stream_eat(s, '}') < 0)
    goto error;
  isl_map_free(map);
 
  return extract_union_set(s->ctx, obj);
error:
  obj.type->free(obj.v);
  isl_map_free(map);
  return NULL;
}
 
/* Read the body of an isl_multi_union_pw_aff from "s",
 * i.e., everything except the parameter specification.
 * "v" contains a description of the identifiers parsed so far.
 * The parameters, if any, are specified by "space".
 *
 * In particular, handle the special case with shared domain constraints.
 * These are specified as
 *
 *  ([...] : ...)
 *
 * and are especially useful for setting the explicit domain
 * of a zero-dimensional isl_multi_union_pw_aff.
 * The core isl_multi_union_pw_aff body ([...]) is read by
 * read_multi_union_pw_aff_body_core.
 */
static __isl_give isl_multi_union_pw_aff *read_multi_union_pw_aff_body(
  __isl_keep isl_stream *s, struct vars *v, __isl_take isl_space *space)
{
  isl_multi_union_pw_aff *mupa;
 
  if (!isl_stream_next_token_is(s, '('))
    return read_multi_union_pw_aff_body_core(s, v, space);
 
  if (isl_stream_eat(s, '(') < 0)
    goto error;
  mupa = read_multi_union_pw_aff_body_core(s, v, isl_space_copy(space));
  if (isl_stream_eat_if_available(s, ':')) {
    isl_union_set *dom;
 
    dom = read_union_set_body(s, v, space);
    mupa = isl_multi_union_pw_aff_intersect_domain(mupa, dom);
  } else {
    isl_space_free(space);
  }
  if (isl_stream_eat(s, ')') < 0)
    return isl_multi_union_pw_aff_free(mupa);
 
  return mupa;
error:
  isl_space_free(space);
  return NULL;
}
 
/* Read an isl_multi_union_pw_aff from "s".
 *
 * The input has the form
 *
 *  [{ [..] : ... ; [..] : ... }, { [..] : ... ; [..] : ... }]
 *
 * or
 *
 *  [..] -> [{ [..] : ... ; [..] : ... }, { [..] : ... ; [..] : ... }]
 *
 * Additionally, a shared domain may be specified as
 *
 *  ([..] : ...)
 *
 * or
 *
 *  [..] -> ([..] : ...)
 *
 * The first case is handled by the caller, the second case
 * is handled by read_multi_union_pw_aff_body.
 *
 * We first check for the special case of an empty tuple "[]".
 * Then we check if there are any parameters.
 * Finally, read the tuple and construct the result.
 */
static __isl_give isl_multi_union_pw_aff *read_multi_union_pw_aff_core(
  __isl_keep isl_stream *s)
{
  struct vars *v;
  isl_set *dom = NULL;
  isl_space *space;
  isl_multi_union_pw_aff *mupa = NULL;
 
  if (next_is_empty_tuple(s)) {
    if (isl_stream_eat(s, '['))
      return NULL;
    if (isl_stream_eat(s, ']'))
      return NULL;
    space = isl_space_set_alloc(s->ctx, 0, 0);
    return isl_multi_union_pw_aff_zero(space);
  }
 
  v = vars_new(s->ctx);
  if (!v)
    return NULL;
 
  dom = isl_set_universe(isl_space_params_alloc(s->ctx, 0));
  if (next_is_param_tuple(s)) {
    dom = read_map_tuple(s, dom, isl_dim_param, v, 0);
    if (isl_stream_eat(s, ISL_TOKEN_TO))
      goto error;
  }
  space = isl_set_get_space(dom);
  isl_set_free(dom);
  mupa = read_multi_union_pw_aff_body(s, v, space);
 
  vars_free(v);
 
  return mupa;
error:
  vars_free(v);
  isl_set_free(dom);
  isl_multi_union_pw_aff_free(mupa);
  return NULL;
}
 
/* Read an isl_multi_union_pw_aff from "s".
 *
 * In particular, handle the special case with shared domain constraints.
 * These are specified as
 *
 *  ([...] : ...)
 *
 * and are especially useful for setting the explicit domain
 * of a zero-dimensional isl_multi_union_pw_aff.
 * The core isl_multi_union_pw_aff ([...]) is read by
 * read_multi_union_pw_aff_core.
 */
__isl_give isl_multi_union_pw_aff *isl_stream_read_multi_union_pw_aff(
  __isl_keep isl_stream *s)
{
  isl_multi_union_pw_aff *mupa;
 
  if (!isl_stream_next_token_is(s, '('))
    return read_multi_union_pw_aff_core(s);
 
  if (isl_stream_eat(s, '(') < 0)
    return NULL;
  mupa = read_multi_union_pw_aff_core(s);
  if (isl_stream_eat_if_available(s, ':')) {
    isl_union_set *dom;
 
    dom = isl_stream_read_union_set(s);
    mupa = isl_multi_union_pw_aff_intersect_domain(mupa, dom);
  }
  if (isl_stream_eat(s, ')') < 0)
    return isl_multi_union_pw_aff_free(mupa);
  return mupa;
}
 
#undef TYPE_BASE
#define TYPE_BASE multi_union_pw_aff
#include "isl_read_from_str_templ.c"
 
__isl_give isl_union_pw_qpolynomial *isl_stream_read_union_pw_qpolynomial(
  __isl_keep isl_stream *s)
{
  struct isl_obj obj;
 
  obj = obj_read(s);
  if (obj.type == isl_obj_pw_qpolynomial) {
    obj.type = isl_obj_union_pw_qpolynomial;
    obj.v = isl_union_pw_qpolynomial_from_pw_qpolynomial(obj.v);
  }
  if (obj.v)
    isl_assert(s->ctx, obj.type == isl_obj_union_pw_qpolynomial,
         goto error);
 
  return obj.v;
error:
  obj.type->free(obj.v);
  return NULL;
}
 
#undef TYPE_BASE
#define TYPE_BASE union_pw_qpolynomial
#include "isl_read_from_str_templ.c"