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devel / comp.lang.c / Re: top_level_regex_token_iterator - Don't match between nested brackets

Re: top_level_regex_token_iterator - Don't match between nested brackets

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https://www.novabbs.com/devel/article-flat.php?id=21570&group=comp.lang.c#21570

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From: ram...@zedat.fu-berlin.de (Stefan Ram)
Newsgroups: comp.lang.c++,comp.lang.c
Subject: Re: top_level_regex_token_iterator - Don't match between nested brackets
Followup-To: comp.lang.c
Date: 30 Apr 2022 20:37:14 GMT
Organization: Stefan Ram
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by: Stefan Ram - Sat, 30 Apr 2022 20:37 UTC

Newsgroups: comp.lang.c++,comp.lang.c
Followup-To: comp.lang.c

Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> writes:
>std::string const str("dog, cat, fish, (frogs,toads), monkeys, elephants, (lizards, amphibians<true,1>), sharks");
>I want to split it by commas to get:
> dog
> cat
> fish
> (frogs,toads)
> monkeys
> elephants
> (lizards, amphibians<true,1>)
> sharks

#include <stdio.h>

void sink( char const * const start, char const * const top )
{ for( char const * p = start; p < top; ++p )putchar( *p );
putchar( '\n' ); }

#define START 0
#define WHITESPACE 1
#define READWORD 2
#define READPAREN 3
#define COMMA 4

int split
( char const * const string,
void( * const sink )( char const * start, char const * top ))
{ int mode = START;
char const * start = string;
for( char const * p = start;; ++p )
{ char const c = *p;
if( mode == START )
{ if( c == '(' )
{ start = p; mode = READPAREN; }
else if( c >= 'a' && c <= 'z' )
{ start = p; mode = READWORD; }
else return c; }
else if( mode == READWORD )
{ if( c >= 'a' && c <= 'z' );
else if( c == ',' || c == '\0' )
{ sink( start, p );
mode = WHITESPACE;
if( !c )return 0; }
else return c; }
else if( mode == READPAREN )
{ if( c == ')' )
{ sink( start, p+1 );
mode = COMMA; }
else if( c == '\0' )
return c; }
else if( mode == COMMA )
{ if( c != ',' )return c;
else mode = WHITESPACE; }
else if( mode == WHITESPACE )
{ if( c != ' ' )return c;
else mode = START; }}}

int main( void )
{ char const * const source =
"dog, cat, fish, (frogs,toads), monkeys, "
"elephants, (lizards, amphibians<true,1>), sharks";
int const error = split( source, sink );
if( error )printf( "\nERROR AT '%c'\n", error ); }

Newsgroups: comp.lang.c++,comp.lang.c
Followup-To: comp.lang.c

Subject	Author
Re: top_level_regex_token_iterator - Don't match between nested brackets	Stefan Ram