workbench/libs/mesa/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 <assert.h>
  26 #include "s_expression.h"
  27
  28 #if defined(__AROS__)
  29 #include <aros/debug.h>
  30 #define printf(fmt, ...)    bug(fmt, ##__VA_ARGS__)
  31 #endif
  32
  33 s_symbol::s_symbol(const char *tmp, size_t n)
  34 {
  35    this->str = ralloc_strndup (this, tmp, n);
  36    assert(this->str != NULL);
  37 }
  38
  39 s_list::s_list()
  40 {
  41 }
  42
  43 static void
  44 skip_whitespace(const char *& src)
  45 {
  46    src += strspn(src, " \v\t\r\n");
  47    /* Also skip Scheme-style comments: semi-colon 'til end of line */
  48    if (src[0] == ';') {
  49       src += strcspn(src, "\n");
  50       skip_whitespace(src);
  51    }
  52 }
  53
  54 static s_expression *
  55 read_atom(void *ctx, const char *& src)
  56 {
  57    s_expression *expr = NULL;
  58
  59    skip_whitespace(src);
  60
  61    size_t n = strcspn(src, "( \v\t\r\n);");
  62    if (n == 0)
  63       return NULL; // no atom
  64
  65    // Check if the atom is a number.
  66    char *float_end = NULL;
  67    double f = glsl_strtod(src, &float_end);
  68    if (float_end != src) {
  69       char *int_end = NULL;
  70       int i = strtol(src, &int_end, 10);
  71       // If strtod matched more characters, it must have a decimal part
  72       if (float_end > int_end)
  73          expr = new(ctx) s_float(f);
  74       else
  75          expr = new(ctx) s_int(i);
  76    } else {
  77       // Not a number; return a symbol.
  78       expr = new(ctx) s_symbol(src, n);
  79    }
  80
  81    src += n;
  82
  83    return expr;
  84 }
  85
  86 s_expression *
  87 s_expression::read_expression(void *ctx, const char *&src)
  88 {
  89    assert(src != NULL);
  90
  91    s_expression *atom = read_atom(ctx, src);
  92    if (atom != NULL)
  93       return atom;
  94
  95    skip_whitespace(src);
  96    if (src[0] == '(') {
  97       ++src;
  98
  99       s_list *list = new(ctx) s_list;
 100       s_expression *expr;
 101
 102       while ((expr = read_expression(ctx, src)) != NULL) {
 103          list->subexpressions.push_tail(expr);
 104       }
 105       skip_whitespace(src);
 106       if (src[0] != ')') {
 107          printf("Unclosed expression (check your parenthesis).\n");
 108          return NULL;
 109       }
 110       ++src;
 111       return list;
 112    }
 113    return NULL;
 114 }
 115
 116 void s_int::print()
 117 {
 118    printf("%d", this->val);
 119 }
 120
 121 void s_float::print()
 122 {
 123    printf("%f", this->val);
 124 }
 125
 126 void s_symbol::print()
 127 {
 128    printf("%s", this->str);
 129 }
 130
 131 void s_list::print()
 132 {
 133    printf("(");
 134    foreach_iter(exec_list_iterator, it, this->subexpressions) {
 135       s_expression *expr = (s_expression*) it.get();
 136       expr->print();
 137       if (!expr->next->is_tail_sentinel())
 138          printf(" ");
 139    }
 140    printf(")");
 141 }
 142
 143 // --------------------------------------------------
 144
 145 bool
 146 s_pattern::match(s_expression *expr)
 147 {
 148    switch (type)
 149    {
 150    case EXPR:   *p_expr = expr; break;
 151    case LIST:   if (expr->is_list())   *p_list   = (s_list *)   expr; break;
 152    case SYMBOL: if (expr->is_symbol()) *p_symbol = (s_symbol *) expr; break;
 153    case NUMBER: if (expr->is_number()) *p_number = (s_number *) expr; break;
 154    case INT:    if (expr->is_int())    *p_int    = (s_int *)    expr; break;
 155    case STRING:
 156       s_symbol *sym = SX_AS_SYMBOL(expr);
 157       if (sym != NULL && strcmp(sym->value(), literal) == 0)
 158          return true;
 159       return false;
 160    };
 161
 162    return *p_expr == expr;
 163 }
 164
 165 bool
 166 s_match(s_expression *top, unsigned n, s_pattern *pattern, bool partial)
 167 {
 168    s_list *list = SX_AS_LIST(top);
 169    if (list == NULL)
 170       return false;
 171
 172    unsigned i = 0;
 173    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 174       if (i >= n)
 175          return partial; /* More actual items than the pattern expected */
 176
 177       s_expression *expr = (s_expression *) it.get();
 178       if (expr == NULL || !pattern[i].match(expr))
 179          return false;
 180
 181       i++;
 182    }
 183
 184    if (i < n)
 185       return false; /* Less actual items than the pattern expected */
 186
 187    return true;
 188 }