bison

问题 My problem is that I am trying to run a problem that I coded using a flex-bison scanner-parser. What my program is supposed to do is take user input (in my case, queries for a database system I'm designing), lex and parse, and then execute the corresponding actions. What actually happens is that my parser code is not correctly interpreting the string literals that I feed it. Here's my code: 130 insertexpr : "INSERT" expr '(' expr ')' 131 132 { 133 $$ = new QLInsert( $2, $4 ); 134 } 135 ; And

问题 I have a problem where I believe there is a cyclic dependency between the headers generated by flex and bison . The type yyscan_t is defined in the lex header and needed in the yacc header. The macro YYSTYPE is defined in the yacc header and needed in the lex header. No matter which order I import the two headers, the other will not be happy. reentrant.lex: %{ #include "reentrant.yacc.h" %} %option reentrant bison-bridge %% [0-9]+ { yylval->int_value = atoi(yytext); return INT_TERM; } [a-zA-Z

问题 I have the following XML grammar which works fine: program : '<' '?'ID attribute_list '?''>' root ; root : '<' ID attribute_list '>' node_list '<''/'ID'>' ; node_list : node_s | node_list node_s ; node_s : node | u_node | ID ; node : '<' ID attribute_list '/''>' ; u_node :'<' ID attribute_list '>' node_list '<''/'ID'>' |'<' ID attribute_list '>' '<''/'ID'>' ; attribute_list : attributes | ; attributes : attribute | attributes attribute ; attribute : ID ASSIGNOP '"' ID '"' | ID ASSIGNOP '"'

问题 I have the following XML grammar which works fine: program : '<' '?'ID attribute_list '?''>' root ; root : '<' ID attribute_list '>' node_list '<''/'ID'>' ; node_list : node_s | node_list node_s ; node_s : node | u_node | ID ; node : '<' ID attribute_list '/''>' ; u_node :'<' ID attribute_list '>' node_list '<''/'ID'>' |'<' ID attribute_list '>' '<''/'ID'>' ; attribute_list : attributes | ; attributes : attribute | attributes attribute ; attribute : ID ASSIGNOP '"' ID '"' | ID ASSIGNOP '"'

问题 Given a lexer definition file, a grammar file (say, postgresql .y , .l flex and bison programs from it's source tree), and a file defined by those lexer and parser (say, an SQL query) to get the AST in some standard form (say, JSON of XML). The most important aspect of this tool is - flexibility of the input format. In my example, I could recreate postgres SQL grammar in ANTLR - but I don't want to. I'd rather just use whatever postgres is using. So even though .y file contains more than the

问题 I'm trying to make a calculator from flex and bison, but I found an error during the compile. Here is the error: C:\GnuWin32\src>gcc lex.yy.c y.tab.c -o tugas tugas.y:51: error: conflicting types for 'yyerror' y.tab.c:1433: error: previous implicit declaration of 'yyerror' was here Here is my .l code : %{ #include <stdio.h> #include "y.tab.h" YYSTYPE yylval; %} plus [+] semi [;] minus [-] var [a-z] digit [0-1]+ equal [:=] %% {var} {yylval = *yytext - 'a'; return VAR;} {digit} {yylval = atoi

问题 In my language i can write a = 1 b = 2 if true { } else { } if true { } **Here is the problem** else {} My grammer doesnt support newlines between statements. An else can only be used with an if. When i add optionalNL in my rule IfExpr: IF rval optionalNL codeBlock optionalNL ELSE codeBlock | IF rval optionalNL codeBlock The optionalNL before the else causes 3 reduce/reduce. Reason is it can reduce using the 2nd rule in IfExpr or reduce to exprLoop where it allows many newlines between

问题 I'm learning flex/bison. I wrote the following program but getting errors. %{ #include <stdio.h> typedef struct node { struct node *left; struct node *right; char *token; }node; node *mknode( node *left, node *right, char *token); void printtree(node *tree); #define YYSTYPE struct node * %} %union { char* str; int num; } %start lines %token <str> WORD %token <str> PLUS MINUS TIMES DIVIDE POWER %token <str> LEFT_PARENTHESIS RIGHT_PARENTHESIS %token <str> END %left PLUS MINUS %left TIMES DIVIDE

问题 Please i am facing a simple problem.. here is the issue, In my lex file i have something similiar to: char *ptr_String; "name = " { BEGIN sName; } <sName>.+ { ptr_String = (char *)calloc(strlen(yytext)+1, sizeof(char)); strcpy(ptr_String, yytext); yylval.sValue = ptr_String; return NAME; } Now in my Yacc file i have something similar to: stmt_Name: NAME { /*Now here i need to get the matched string of <sName>.+ and measure it's length. */ /*The aim is simply outputing the name to the screen

问题 Please i am facing a simple problem.. here is the issue, In my lex file i have something similiar to: char *ptr_String; "name = " { BEGIN sName; } <sName>.+ { ptr_String = (char *)calloc(strlen(yytext)+1, sizeof(char)); strcpy(ptr_String, yytext); yylval.sValue = ptr_String; return NAME; } Now in my Yacc file i have something similar to: stmt_Name: NAME { /*Now here i need to get the matched string of <sName>.+ and measure it's length. */ /*The aim is simply outputing the name to the screen