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Diffstat (limited to 'src/lexer.ll')
| -rw-r--r-- | src/lexer.ll | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/src/lexer.ll b/src/lexer.ll new file mode 100644 index 0000000..8ec48e2 --- /dev/null +++ b/src/lexer.ll @@ -0,0 +1,223 @@ +/* + * lexer.ll - part of abakus + * Copyright (C) 2004, 2005 Michael Pyne <michael.pyne@kdemail.net> + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02110-1301 USA + */ +%option noyywrap +%{ +#define YY_NO_UNPUT + +#include <kdebug.h> + +#include "node.h" +#include "function.h" +#include "parser_yacc.hpp" +#include "result.h" + +int yyCurTokenPos; +int yyThisTokenLength; + +int yyparse(void); +%} + +DIGITS [0-9]+ +HEX [0-9A-Fa-f]+ +%% + + /* Always skip whitespace */ +[ \t]* { yyCurTokenPos += yyThisTokenLength; yyThisTokenLength = yyleng; } + + /* Power operator */ +"**" { + yyCurTokenPos += yyThisTokenLength; + yyThisTokenLength = 2; + return POWER; +} + +"^" { + yyCurTokenPos += yyThisTokenLength; + yyThisTokenLength = 1; + return POWER; +} + +[sS][eE][tT] { + yyCurTokenPos += yyThisTokenLength; + yyThisTokenLength = 3; + return SET; +} + +[rR][eE][mM][oO][vV][eE] { + yyCurTokenPos += yyThisTokenLength; + yyThisTokenLength = 6; + return REMOVE; +} + +[dD][eE][rR][iI][vV] { + yyCurTokenPos += yyThisTokenLength; + yyThisTokenLength = 5; + return DERIV; +} + + /* Read numbers of the form with at least the decimal point and trailing + * digits, such as .32, -234.45, .0, etc. Numbers are only read in the BEGIN + * state. + */ +{DIGITS}*([\.,]{DIGITS}+)(e[-+]?{DIGITS}+)? { + yyCurTokenPos += yyThisTokenLength; + yyThisTokenLength = yyleng; + return NUM; +} + + /* Read Hex */ +0x({HEX}+)? { + yyCurTokenPos += yyThisTokenLength; + yyThisTokenLength = yyleng; + return NUM; +} + + /* Read numbers with at least the integral part, such as +4234, -34e8, etc. + * Numbers are only read in the BEGIN state. + */ +{DIGITS}+([\.,]{DIGITS}*)?(e[-+]?{DIGITS}+)? { + yyCurTokenPos += yyThisTokenLength; + yyThisTokenLength = yyleng; + return NUM; +} + +[nN][aA][nN] { + yyCurTokenPos += yyThisTokenLength; + yyThisTokenLength = yyleng; + return NUM; +} + +[iI][nN][fF] { + yyCurTokenPos += yyThisTokenLength; + yyThisTokenLength = yyleng; + return NUM; +} + + /* This detects textual input, and if it isn't pre-declared by the parser (in + * other words, if it isn't a function), then it is returned as an identifier. + */ +[a-zA-Z_][a-zA-Z_0-9]* { + yyCurTokenPos += yyThisTokenLength; + yyThisTokenLength = yyleng; + + if(FunctionManager::instance()->isFunction(yytext)) + return FN; + else { + return ID; + } +} + + /* All other characters are returned as-is to the parser, who can accept or + * reject it as needed. + */ +. { + yyCurTokenPos += yyThisTokenLength; + yyThisTokenLength = 1; + return *yytext; +} + +%% + +class Lexer::Private +{ +public: + YY_BUFFER_STATE buffer; + int lastToken, thisToken; + int lastPos, thisPos; + QString lastTokenData, thisTokenData; +}; + +/* Declared in function.h, implemented here in lexer.l since this is where + * all the yy_*() functions and types are defined. + */ +Lexer::Lexer(const QString &expr) : + m_private(new Private) +{ + const char *exprString = expr.latin1(); + + yyCurTokenPos = 0; + yyThisTokenLength = 0; + + m_private->buffer = yy_scan_string(exprString ? exprString : ""); + m_private->lastToken = -1; + m_private->lastPos = -1; + + m_private->thisToken = yylex(); + m_private->thisTokenData = QString(yytext); + + if(yyCurTokenPos != 0) + { + kdError() << "yyCurTokenPos should be 0!!\n"; + } + + m_private->thisPos = yyCurTokenPos; +} + +Lexer::~Lexer() +{ + yy_delete_buffer(m_private->buffer); + delete m_private; +} + +bool Lexer::hasNext() const +{ + return m_private->thisToken > 0; +} + +int Lexer::nextType() +{ + m_private->lastTokenData = m_private->thisTokenData; + m_private->lastPos = m_private->thisPos; + m_private->lastToken = m_private->thisToken; + + m_private->thisToken = yylex(); + m_private->thisTokenData = QString(yytext); + m_private->thisPos = yyCurTokenPos; + + return m_private->lastToken; +} + +QString Lexer::tokenValue() const +{ + return m_private->lastTokenData; +} + +int Lexer::tokenPos() const +{ + return m_private->lastPos; +} + +/* Declared in function.h, implemented here in lexer.l since this is where + * all the yy_*() functions and types are defined. + */ +Abakus::number_t parseString(const char *str) +{ + YY_BUFFER_STATE buffer = yy_scan_string(str); + + yyCurTokenPos = 0; + yyThisTokenLength = 0; + + yyparse(); + yy_delete_buffer(buffer); + + if(Result::lastResult()->type() != Result::Value) + return Abakus::number_t(); + + return Result::lastResult()->result()->value(); +} |