mingodad
commented
2 years ago Also when trying to use the grammar shown bellow I'm getting syntax error, it seems that the problem is this rule:
definition <- {printf("\n\n");} name {printf(" ::=\n\t");} S (asttag S)? arrow expI'm using an action before a pattern/element -> name, packcc does accept it.
Grammar that give the problem:
%prefix "lpeg_re"
%header {
typedef struct {
int doOutput;
} lpeg_re_st;
}
%auxil "lpeg_re_st *"
pattern <- exp !. {printf("\n\n");}
exp <- S (grammar / alternative)
alternative <- seq (<'/'> {printf("\n\t%s ", $1);} S seq)*
seq <- prefix*
prefix <- '&' S prefix / '!' S prefix / suffix
suffix <- primary S ((<[+*?]> {printf(" %s ", $1);}
/ '^' [+-]? num
/ '->' {auxil->doOutput=0;} S (string / '{}' / name / num) {auxil->doOutput=1;}
/ '=>' {auxil->doOutput=0;} S name) S)* {auxil->doOutput=1;}
primary <- '(' {printf(" ( ");} exp ')' {printf(" ) ");} / (string / keyword) / class / defined
/ '{:' (name ':')? exp ':}'
/ '=' name
/ '@' exp
/ '{}'
/ '{~' exp '~}'
/ '{|' exp '|}' # missing table capture
/ '{' exp '}'
/ '~?' # Expected match
/ '~>' S ( 'foldleft' / 'foldright' / 'rfoldleft' / 'rfoldright' )
/ '$' (string / name / num) # Arbitrary capture
/ '.'
/ name S !(asttag / arrow )
/ '<' name '>' ## old-style non terminals
/ '^' name
/ '%{' S name S '}'
grammar <- definition+
definition <- {printf("\n\n");} name {printf(" ::=\n\t");} S (asttag S)? arrow exp
class <- <'[' '^'? item (!']' item)* ']'> { printf(" %s ", $1);}
item <- defined / range / .
range <- . '-' [^\]]
S <- ([ \t\f\r\n] / '--' [^\r\n]*)* # spaces and comments
name <- <[A-Za-z_]([A-Za-z0-9_] / '-' !'>' )*> { if(auxil->doOutput) printf(" %s ", $1);}
arrow <- ( '<--' / '<==' / '<-|' / '<-' )
num <- [0-9]+
string <- <'"' [^"]* '"' / "'" [^']* "'"> { if(auxil->doOutput) printf(" %s ", $1);}
defined <- '%' name
keyword <- '`' <[^`]+> '`' { printf(" '%s' ", $1);}
asttag <- ':' S name
%%
int main() {
lpeg_re_st state;
state.doOutput = 1;
lpeg_re_context_t *ctx = lpeg_re_create(&state);
while (lpeg_re_parse(ctx, NULL));
lpeg_re_destroy(ctx);
return 0;
}
dolik-rce
I'm on Ubuntu 18.04 and using gcc9 and to be able to build I needed to add this to
CMakefile.txt: