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 static s_expression *
  42 read_atom(void *ctx, const char *& src)
  43 {
  44    s_expression *expr = NULL;
  45
  46    // Skip leading spaces.
  47    src += strspn(src, " \v\t\r\n");
  48
  49    size_t n = strcspn(src, "( \v\t\r\n)");
  50    if (n == 0)
  51       return NULL; // no atom
  52
  53    // Check if the atom is a number.
  54    char *float_end = NULL;
  55    double f = glsl_strtod(src, &float_end);
  56    if (float_end != src) {
  57       char *int_end = NULL;
  58       int i = strtol(src, &int_end, 10);
  59       // If strtod matched more characters, it must have a decimal part
  60       if (float_end > int_end)
  61          expr = new(ctx) s_float(f);
  62       else
  63          expr = new(ctx) s_int(i);
  64    } else {
  65       // Not a number; return a symbol.
  66       expr = new(ctx) s_symbol(src, n);
  67    }
  68
  69    src += n;
  70
  71    return expr;
  72 }
  73
  74 s_expression *
  75 s_expression::read_expression(void *ctx, const char *&src)
  76 {
  77    assert(src != NULL);
  78
  79    s_expression *atom = read_atom(ctx, src);
  80    if (atom != NULL)
  81       return atom;
  82
  83    // Skip leading spaces.
  84    src += strspn(src, " \v\t\r\n");
  85    if (src[0] == '(') {
  86       ++src;
  87
  88       s_list *list = new(ctx) s_list;
  89       s_expression *expr;
  90
  91       while ((expr = read_expression(ctx, src)) != NULL) {
  92          list->subexpressions.push_tail(expr);
  93       }
  94       src += strspn(src, " \v\t\r\n");
  95       if (src[0] != ')') {
  96          printf("Unclosed expression (check your parenthesis).\n");
  97          return NULL;
  98       }
  99       ++src;
 100       return list;
 101    }
 102    return NULL;
 103 }
 104
 105 void s_int::print()
 106 {
 107    printf("%d", this->val);
 108 }
 109
 110 void s_float::print()
 111 {
 112    printf("%f", this->val);
 113 }
 114
 115 void s_symbol::print()
 116 {
 117    printf("%s", this->str);
 118 }
 119
 120 void s_list::print()
 121 {
 122    printf("(");
 123    foreach_iter(exec_list_iterator, it, this->subexpressions) {
 124       s_expression *expr = (s_expression*) it.get();
 125       expr->print();
 126       if (!expr->next->is_tail_sentinel())
 127          printf(" ");
 128    }
 129    printf(")");
 130 }
 131
 132 // --------------------------------------------------
 133
 134 bool
 135 s_pattern::match(s_expression *expr)
 136 {
 137    switch (type)
 138    {
 139    case EXPR:   *p_expr = expr; break;
 140    case LIST:   if (expr->is_list())   *p_list   = (s_list *)   expr; break;
 141    case SYMBOL: if (expr->is_symbol()) *p_symbol = (s_symbol *) expr; break;
 142    case NUMBER: if (expr->is_number()) *p_number = (s_number *) expr; break;
 143    case INT:    if (expr->is_int())    *p_int    = (s_int *)    expr; break;
 144    case STRING:
 145       s_symbol *sym = SX_AS_SYMBOL(expr);
 146       if (sym != NULL && strcmp(sym->value(), literal) == 0)
 147          return true;
 148       return false;
 149    };
 150
 151    return *p_expr == expr;
 152 }
 153
 154 bool
 155 s_match(s_expression *top, unsigned n, s_pattern *pattern, bool partial)
 156 {
 157    s_list *list = SX_AS_LIST(top);
 158    if (list == NULL)
 159       return false;
 160
 161    unsigned i = 0;
 162    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 163       if (i >= n)
 164          return partial; /* More actual items than the pattern expected */
 165
 166       s_expression *expr = (s_expression *) it.get();
 167       if (expr == NULL || !pattern[i].match(expr))
 168          return false;
 169
 170       i++;
 171    }
 172
 173    if (i < n)
 174       return false; /* Less actual items than the pattern expected */
 175
 176    return true;
 177 }