X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Fparser%2Fparser.cpp;h=de6b269ac1ac934209d16989e2d836b431e0db8d;hp=1e905cf5ff1133e4d2074cf05dd5992a9d813467;hb=99901bd5c74203caece07e3e2948780887a0e822;hpb=b8150271ff497c2ef0c2a8748f5f53b4f1bab7c8;ds=sidebyside diff --git a/ginac/parser/parser.cpp b/ginac/parser/parser.cpp index 1e905cf5..de6b269a 100644 --- a/ginac/parser/parser.cpp +++ b/ginac/parser/parser.cpp @@ -1,13 +1,72 @@ -#include -#include -#include "parser.hpp" -#include "lexer.hpp" -#include "debug.hpp" +/** @file parser.cpp + * + * Implementation of GiNaC's parser. */ + +/* + * GiNaC Copyright (C) 1999-2011 Johannes Gutenberg University Mainz, Germany + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "parser.h" +#include "lexer.h" +#include "debug.h" #include "mul.h" #include "constant.h" +#include "function.h" +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif -namespace GiNaC +#ifdef HAVE_STDINT_H +#include // for uintptr_t +#endif +#include +#include + +namespace GiNaC { + +// +// Find out if ptr is a pointer to a function or a specially crafted integer. +// It's possible to distinguish between these because functions are aligned. +// Returns true if ptr is a pointer and false otherwise. +static bool decode_serial(unsigned& serial, const reader_func ptr) { + uintptr_t u = (uintptr_t)(void *)ptr; + if (u & 1) { + u >>= 1; + serial = (unsigned)u; + return false; + } + return true; +} + +// Figures out if ptr is a pointer to function or a serial of GiNaC function. +// In the former case calls that function, in the latter case constructs +// GiNaC function with corresponding serial and arguments. +static ex dispatch_reader_fcn(const reader_func ptr, const exvector& args) +{ + unsigned serial = 0; // dear gcc, could you please shut up? + bool is_ptr = decode_serial(serial, ptr); + if (is_ptr) + return ptr(args); + else + return function(serial, args); +} +// + /// identifier_expr: identifier | identifier '(' expression* ')' ex parser::parse_identifier_expr() @@ -43,7 +102,9 @@ ex parser::parse_identifier_expr() Parse_error_("no function \"" << name << "\" with " << args.size() << " arguments"); } - ex ret = reader->second(args); + // reader->second might be a pointer to a C++ function or a specially + // crafted serial of a GiNaC::function. + ex ret = dispatch_reader_fcn(reader->second, args); return ret; } @@ -59,22 +120,53 @@ ex parser::parse_paren_expr() return e; } -extern numeric* _num_1_p; +/// lst_expr: '{' expression { ',' expression } '}' +ex parser::parse_lst_expr() +{ + get_next_tok(); // eat {. + + lst list; + if (token != '}') { + while (true) { + ex e = parse_expression(); // expression(); + list.append(e); + + if (token == '}') { + break; + } + + if (token != ',') { + Parse_error("expected '}'"); + } + + get_next_tok(); // eat ','. + } + } + // Eat the '}'. + get_next_tok(); + + return list; +} + +extern const ex _ex0; /// unary_expr: [+-] expression -ex parser::parse_unary_expr(const int s) +ex parser::parse_unary_expr() { - // consume '-' (or '+') - get_next_tok(); - ex v = parse_expression(); - switch (s) { - case '-': - return (new mul(v, *_num_1_p))->setflag(status_flags::dynallocated); - case '+': - return v; - default: - Parse_error_("invalid unary operator \"" << char(s) << "\""); - } + // Unlike most other parse_* method this one does NOT consume + // current token so parse_binop_rhs() knows what kind of operator + // is being parsed. + + // There are different kinds of expressions which need to be handled: + // -a+b + // -(a) + // +a + // +(a) + // Delegete the work to parse_binop_rhs(), otherwise we end up + // duplicating it here. + ex lhs = _ex0; // silly trick + ex e = parse_binop_rhs(0, lhs); + return e; } /// primary: identifier_expr | number_expr | paren_expr | unary_expr @@ -87,10 +179,11 @@ ex parser::parse_primary() return parse_number_expr(); case '(': return parse_paren_expr(); + case '{': + return parse_lst_expr(); case '-': - return parse_unary_expr('-'); case '+': - return parse_unary_expr('+'); + return parse_unary_expr(); case lexer::token_type::literal: return parse_literal_expr(); case lexer::token_type::eof: @@ -118,6 +211,7 @@ ex parser::parse_number_expr() /// literal_expr: 'I' | 'Pi' | 'Euler' | 'Catalan' ex parser::parse_literal_expr() { + get_next_tok(); // consume the literal if (scanner->str == "I") return I; else if (scanner->str == "Pi") @@ -134,6 +228,13 @@ ex parser::operator()(std::istream& input) scanner->switch_input(&input); get_next_tok(); ex ret = parse_expression(); + // parse_expression() stops if it encounters an unknown token. + // This is not a bug: since the parser is recursive checking + // whether the next token is valid is responsibility of the caller. + // Hence make sure nothing is left in the stream: + if (token != lexer::token_type::eof) + Parse_error("expected EOF"); + return ret; } @@ -150,9 +251,9 @@ int parser::get_next_tok() return token; } -parser::parser(const symtab& syms_, const prototype_table& funcs_, - const bool strict_) : strict(strict_), funcs(funcs_), - syms(syms_) +parser::parser(const symtab& syms_, const bool strict_, + const prototype_table& funcs_) : strict(strict_), + funcs(funcs_), syms(syms_) { scanner = new lexer(); }