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)
  32 {
  33    this->str = new char [strlen(tmp) + 1];
  34    strcpy(this->str, tmp);
  35 }
  36
  37 s_symbol::~s_symbol()
  38 {
  39    delete [] this->str;
  40    this->str = NULL;
  41 }
  42
  43 s_list::s_list()
  44 {
  45 }
  46
  47 s_list::~s_list()
  48 {
  49    exec_list_iterator it(this->subexpressions.iterator());
  50    while (it.has_next())
  51       it.remove();
  52
  53    assert(this->subexpressions.is_empty());
  54 }
  55
  56 unsigned
  57 s_list::length() const
  58 {
  59    unsigned i = 0;
  60    foreach_iter(exec_list_iterator, it, this->subexpressions) {
  61       i++;
  62    }
  63    return i;
  64 }
  65
  66 static s_expression *
  67 read_atom(const char *& src)
  68 {
  69    char buf[101];
  70    int n;
  71    if (sscanf(src, " %100[^( \v\t\r\n)]%n", buf, &n) != 1)
  72       return NULL; // no atom
  73    src += n;
  74
  75    // Check if the atom is a number.
  76    char *float_end = NULL;
  77    double f = strtod(buf, &float_end);
  78    if (float_end != buf) {
  79       char *int_end = NULL;
  80       int i = strtol(buf, &int_end, 10);
  81       // If strtod matched more characters, it must have a decimal part
  82       if (float_end > int_end)
  83          return new s_float(f);
  84
  85       return new s_int(i);
  86    }
  87    // Not a number; return a symbol.
  88    return new s_symbol(buf);
  89 }
  90
  91 s_expression *
  92 s_expression::read_expression(const char *&src)
  93 {
  94    assert(src != NULL);
  95
  96    s_expression *atom = read_atom(src);
  97    if (atom != NULL)
  98       return atom;
  99
 100    char c;
 101    int n;
 102    if (sscanf(src, " %c%n", &c, &n) == 1 && c == '(') {
 103       src += n;
 104
 105       s_list *list = new s_list;
 106       s_expression *expr;
 107
 108       while ((expr = read_expression(src)) != NULL) {
 109          list->subexpressions.push_tail(expr);
 110       }
 111       if (sscanf(src, " %c%n", &c, &n) != 1 || c != ')') {
 112          printf("Unclosed expression (check your parenthesis).\n");
 113          return NULL;
 114       }
 115       src += n;
 116       return list;
 117    }
 118    return NULL;
 119 }
 120
 121 void s_int::print()
 122 {
 123    printf("%d", this->val);
 124 }
 125
 126 void s_float::print()
 127 {
 128    printf("%f", this->val);
 129 }
 130
 131 void s_symbol::print()
 132 {
 133    printf("%s", this->str);
 134 }
 135
 136 void s_list::print()
 137 {
 138    printf("(");
 139    foreach_iter(exec_list_iterator, it, this->subexpressions) {
 140       s_expression *expr = (s_expression*) it.get();
 141       expr->print();
 142       printf(" ");
 143    }
 144    printf(")");
 145 }
 146