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 */ 47class s_expression : public exec_node 48{ 49public: 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 hieralloc 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 68protected: 69 s_expression() { } 70 virtual ~s_expression() { } // GCC error about accessible nonvirtual dctor 71}; 72 73/* Atoms */ 74 75class s_number : public s_expression 76{ 77public: 78 bool is_number() const { return true; } 79 80 virtual float fvalue() = 0; 81 82protected: 83 s_number() { } 84}; 85 86class s_int : public s_number 87{ 88public: 89 s_int(int x) : val(x) { } 90 91 bool is_int() const { return true; } 92 93 float fvalue() { return float(this->val); } 94 int value() { return this->val; } 95 96 void print(); 97 98private: 99 int val; 100}; 101 102class s_float : public s_number 103{ 104public: 105 s_float(float x) : val(x) { } 106 107 float fvalue() { return this->val; } 108 109 void print(); 110 111private: 112 float val; 113}; 114 115class s_symbol : public s_expression 116{ 117public: 118 s_symbol(const char *, size_t); 119 120 bool is_symbol() const { return true; } 121 122 const char *value() { return this->str; } 123 124 void print(); 125 126private: 127 char *str; 128}; 129 130/* Lists of expressions: (expr1 ... exprN) */ 131class s_list : public s_expression 132{ 133public: 134 s_list(); 135 136 virtual bool is_list() const { return true; } 137 unsigned length() const; 138 139 void print(); 140 141 exec_list subexpressions; 142}; 143 144#endif /* S_EXPRESSION_H */ 145