src/glsl/s_expression.cpp

   1 /* -*- c++ -*- */
   2 /*
   3  * Copyright © 2010 Intel Corporation
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22  * DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 #include <cstdio>
  26 #include <cstdlib>
  27 #include <cstring>
  28 #include <assert.h>
  29 #include "s_expression.h"
  30
  31 s_symbol::s_symbol(const char *tmp, size_t n)
  32 {
  33    this->str = talloc_strndup (this, tmp, n);
  34    assert(this->str != NULL);
  35 }
  36
  37 s_list::s_list()
  38 {
  39 }
  40
  41 unsigned
  42 s_list::length() const
  43 {
  44    unsigned i = 0;
  45    foreach_iter(exec_list_iterator, it, this->subexpressions) {
  46       i++;
  47    }
  48    return i;
  49 }
  50
  51 static s_expression *
  52 read_atom(void *ctx, const char *& src)
  53 {
  54    s_expression *expr = NULL;
  55
  56    // Skip leading spaces.
  57    src += strspn(src, " \v\t\r\n");
  58
  59    size_t n = strcspn(src, "( \v\t\r\n)");
  60    if (n == 0)
  61       return NULL; // no atom
  62
  63    // Check if the atom is a number.
  64    char *float_end = NULL;
  65    double f = strtod(src, &float_end);
  66    if (float_end != src) {
  67       char *int_end = NULL;
  68       int i = strtol(src, &int_end, 10);
  69       // If strtod matched more characters, it must have a decimal part
  70       if (float_end > int_end)
  71          expr = new(ctx) s_float(f);
  72       else
  73          expr = new(ctx) s_int(i);
  74    } else {
  75       // Not a number; return a symbol.
  76       expr = new(ctx) s_symbol(src, n);
  77    }
  78
  79    src += n;
  80
  81    return expr;
  82 }
  83
  84 s_expression *
  85 s_expression::read_expression(void *ctx, const char *&src)
  86 {
  87    assert(src != NULL);
  88
  89    s_expression *atom = read_atom(ctx, src);
  90    if (atom != NULL)
  91       return atom;
  92
  93    // Skip leading spaces.
  94    src += strspn(src, " \v\t\r\n");
  95    if (src[0] == '(') {
  96       ++src;
  97
  98       s_list *list = new(ctx) s_list;
  99       s_expression *expr;
 100
 101       while ((expr = read_expression(ctx, src)) != NULL) {
 102          list->subexpressions.push_tail(expr);
 103       }
 104       src += strspn(src, " \v\t\r\n");
 105       if (src[0] != ')') {
 106          printf("Unclosed expression (check your parenthesis).\n");
 107          return NULL;
 108       }
 109       ++src;
 110       return list;
 111    }
 112    return NULL;
 113 }
 114
 115 void s_int::print()
 116 {
 117    printf("%d", this->val);
 118 }
 119
 120 void s_float::print()
 121 {
 122    printf("%f", this->val);
 123 }
 124
 125 void s_symbol::print()
 126 {
 127    printf("%s", this->str);
 128 }
 129
 130 void s_list::print()
 131 {
 132    printf("(");
 133    foreach_iter(exec_list_iterator, it, this->subexpressions) {
 134       s_expression *expr = (s_expression*) it.get();
 135       expr->print();
 136       printf(" ");
 137    }
 138    printf(")");
 139 }
 140