3 * Implementation of GiNaC's parser. */
6 * GiNaC Copyright (C) 1999-2024 Johannes Gutenberg University Mainz, Germany
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
30 #include "operators.h"
32 #include <cstdint> // for uintptr_t
39 // Find out if ptr is a pointer to a function or a specially crafted integer.
40 // It's possible to distinguish between these because functions are aligned.
41 // Returns true if ptr is a pointer and false otherwise.
42 static bool decode_serial(unsigned& serial, const reader_func ptr)
44 uintptr_t u = (uintptr_t)(void *)ptr;
53 // Figures out if ptr is a pointer to function or a serial of GiNaC function.
54 // In the former case calls that function, in the latter case constructs
55 // GiNaC function with corresponding serial and arguments.
56 static ex dispatch_reader_fcn(const reader_func ptr, const exvector& args)
58 unsigned serial = 0; // dear gcc, could you please shut up?
59 bool is_ptr = decode_serial(serial, ptr);
63 return function(serial, args);
68 /// identifier_expr: identifier | identifier '(' expression* ')'
69 ex parser::parse_identifier_expr()
71 std::string name = scanner->str;
72 get_next_tok(); // eat identifier.
74 if (token != '(') // symbol
75 return find_or_insert_symbol(name, syms, strict);
77 // function/ctor call.
78 get_next_tok(); // eat (
82 ex e = parse_expression();
89 Parse_error("expected ')' or ',' in argument list");
96 prototype the_prototype = make_pair(name, args.size());
97 auto reader = funcs.find(the_prototype);
98 if (reader == funcs.end()) {
99 Parse_error_("no function \"" << name << "\" with " <<
100 args.size() << " arguments");
102 // reader->second might be a pointer to a C++ function or a specially
103 // crafted serial of a GiNaC::function.
104 ex ret = dispatch_reader_fcn(reader->second, args);
108 /// paren_expr: '(' expression ')'
109 ex parser::parse_paren_expr()
111 get_next_tok(); // eat (.
112 ex e = parse_expression();
115 Parse_error("expected ')'");
116 get_next_tok(); // eat ).
120 /// lst_expr: '{' expression { ',' expression } '}'
121 ex parser::parse_lst_expr()
123 get_next_tok(); // eat {.
128 ex e = parse_expression(); // expression();
136 Parse_error("expected '}'");
139 get_next_tok(); // eat ','.
148 /// primary: identifier_expr | number_expr | paren_expr | unary_expr
149 ex parser::parse_primary()
152 case lexer::token_type::identifier:
153 return parse_identifier_expr();
154 case lexer::token_type::number:
155 return parse_number_expr();
157 return parse_paren_expr();
159 return parse_lst_expr();
161 return -parse_unary_expr();
163 return parse_unary_expr();
164 case lexer::token_type::literal:
165 return parse_literal_expr();
166 case lexer::token_type::eof:
168 Parse_error("unexpected token");
172 /// expression ::= primary binoprhs
173 ex parser::parse_expression()
175 ex lhs = parse_primary();
176 ex res = parse_binop_rhs(0, lhs);
180 /// number_expr: number
181 ex parser::parse_number_expr()
183 ex n = numeric(scanner->str.c_str());
184 get_next_tok(); // consume the number
188 /// literal_expr: 'I' | 'Pi' | 'Euler' | 'Catalan'
189 ex parser::parse_literal_expr()
191 get_next_tok(); // consume the literal
192 if (scanner->str == "I")
194 else if (scanner->str == "Pi")
196 else if (scanner->str == "Euler")
198 else if (scanner->str == "Catalan")
200 bug("unknown literal: \"" << scanner->str << "\"");
203 ex parser::operator()(std::istream& input)
205 scanner->switch_input(&input);
207 ex ret = parse_expression();
208 // parse_expression() stops if it encounters an unknown token.
209 // This is not a bug: since the parser is recursive checking
210 // whether the next token is valid is responsibility of the caller.
211 // Hence make sure nothing is left in the stream:
212 if (token != lexer::token_type::eof)
213 Parse_error("expected EOF");
218 ex parser::operator()(const std::string& input)
220 std::istringstream is(input);
221 ex ret = operator()(is);
225 int parser::get_next_tok()
227 token = scanner->gettok();
231 parser::parser(const symtab& syms_, const bool strict_,
232 const prototype_table& funcs_) : strict(strict_),
233 funcs(funcs_), syms(syms_)
235 scanner = new lexer();