src/glsl/s_expression.h

   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 #pragma once
  26 #ifndef S_EXPRESSION_H
  27 #define S_EXPRESSION_H
  28
  29 #include "strtod.h"
  30 #include "list.h"
  31
  32 #define SX_AS_(t,x) ((x) && ((s_expression*) x)->is_##t()) ? ((s_##t*) (x)) \
  33                                                            : NULL
  34 #define SX_AS_LIST(x)   SX_AS_(list, x)
  35 #define SX_AS_SYMBOL(x) SX_AS_(symbol, x)
  36 #define SX_AS_NUMBER(x) SX_AS_(number, x)
  37 #define SX_AS_INT(x)    SX_AS_(int, x)
  38
  39 /* For our purposes, S-Expressions are:
  40  * - <int>
  41  * - <float>
  42  * - symbol
  43  * - (expr1 expr2 ... exprN)     where exprN is an S-Expression
  44  *
  45  * Unlike LISP/Scheme, we do not support (foo . bar) pairs.
  46  */
  47 class s_expression : public exec_node
  48 {
  49 public:
  50    /**
  51     * Read an S-Expression from the given string.
  52     * Advances the supplied pointer to just after the expression read.
  53     *
  54     * Any allocation will be performed with 'ctx' as the talloc owner.
  55     */
  56    static s_expression *read_expression(void *ctx, const char *&src);
  57
  58    /**
  59     * Print out an S-Expression.  Useful for debugging.
  60     */
  61    virtual void print() = 0;
  62
  63    virtual bool is_list()   const { return false; }
  64    virtual bool is_symbol() const { return false; }
  65    virtual bool is_number() const { return false; }
  66    virtual bool is_int()    const { return false; }
  67
  68 protected:
  69    s_expression() { }
  70 };
  71
  72 /* Atoms */
  73
  74 class s_number : public s_expression
  75 {
  76 public:
  77    bool is_number() const { return true; }
  78
  79    virtual float fvalue() = 0;
  80
  81 protected:
  82    s_number() { }
  83 };
  84
  85 class s_int : public s_number
  86 {
  87 public:
  88    s_int(int x) : val(x) { }
  89
  90    bool is_int() const { return true; }
  91
  92    float fvalue() { return float(this->val); }
  93    int value() { return this->val; }
  94
  95    void print();
  96
  97 private:
  98    int val;
  99 };
 100
 101 class s_float : public s_number
 102 {
 103 public:
 104    s_float(float x) : val(x) { }
 105
 106    float fvalue() { return this->val; }
 107
 108    void print();
 109
 110 private:
 111    float val;
 112 };
 113
 114 class s_symbol : public s_expression
 115 {
 116 public:
 117    s_symbol(const char *, size_t);
 118
 119    bool is_symbol() const { return true; }
 120
 121    const char *value() { return this->str; }
 122
 123    void print();
 124
 125 private:
 126    char *str;
 127 };
 128
 129 /* Lists of expressions: (expr1 ... exprN) */
 130 class s_list : public s_expression
 131 {
 132 public:
 133    s_list();
 134
 135    virtual bool is_list() const { return true; }
 136    unsigned length() const;
 137
 138    void print();
 139
 140    exec_list subexpressions;
 141 };
 142
 143 #endif /* S_EXPRESSION_H */