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