bison

问题 I want to create a read-eval-print loop using flex/bison parser. Trouble is, the flex generated lexer wants input of type FILE* and i would like it to be char*. Is there anyway to do this? One suggestion has been to create a pipe, feed it the string and open the file descriptor and send to the lexer. This is fairly simple but it feels convoluted and not very platform independent. Is there a better way? 回答1: The following routines are available for setting up input buffers for scanning in

问题 How do I remove shift-reduce conflict for bison for the given grammar? selection-stmt -> if ( expression ) statement | if ( expression ) statement else statement A solution giving the modified grammar would be highly appreciated. 回答1: There is a much simpler solution. If you know how LR parsers work, then you know that the conflict happens here: if ( expression ) statement * else statement where the star marks the current position of the cursor. The question the parser must answer is "should

问题 I\'m having Lex and YACC files to parse my files ( .l file and .y file). How to compile those files and how to make equivalent .c file for them in windows platform? 回答1: As for today (2011-04-05, updated 2017-11-29) you will need the lastest versions of: flex-2.5.4a-1.exe bison-2.4.1-setup.exe After that, do a full install in a directory of your preference without spaces in the name . I suggest C:\GnuWin32 . Do not install it in the default (C:\Program Files (x86)\GnuWin32) because bison has

问题 flex code: 1 %option noyywrap nodefault yylineno case-insensitive 2 %{ 3 #include \"stdio.h\" 4 #include \"tp.tab.h\" 5 %} 6 7 %% 8 \"{\" {return \'{\';} 9 \"}\" {return \'}\';} 10 \";\" {return \';\';} 11 \"create\" {return CREATE;} 12 \"cmd\" {return CMD;} 13 \"int\" {yylval.intval = 20;return INT;} 14 [a-zA-Z]+ {yylval.strval = yytext;printf(\"id:%s\\n\" , yylval.strval);return ID;} 15 [ \\t\\n] 16 <<EOF>> {return 0;} 17 . {printf(\"mistery char\\n\");} 18 bison code: 1 %{ 2 #include \

问题 I\'m writing a small interpreter for a simple BASIC like language as an exercise on an AVR microcontroller in C using the avr-gcc toolchain. However, I\'m wondering if there are any open source tools out there that could help me writing the lexer and parser. If I would write this to run on my Linux box, I could use flex/bison. Now that I restricted myself to an 8-bit platform I have to do it all by hand, or not? 回答1: I've implemented a parser for a simple command language targeted for the