Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!ig!arizona!rupley
From: rupley@arizona.edu (John Rupley)
Newsgroups: comp.lang.c
Subject: Re: Scrunch blank lines
Summary: Lex solution
Message-ID: <10029@megaron.arizona.edu>
Date: 31 Mar 89 21:13:38 GMT
References: <7150@siemens.UUCP> <9900010@bradley> <4896@cbnews.ATT.COM> <26389@cornell.UUCP>
Distribution: na
Organization: U of Arizona CS Dept, Tucson
Lines: 23


From rupley!local Fri Mar 31 13:43:14 1989
In article <620@gonzo.UUCP> daveb@gonzo.UUCP (Dave Brower) writes:
>So, I offer this week's challenge:  Smallest program that will take
>"blank line" style cpp output on stdin and send to stdout a scrunched
>version with appropriate #line directives.

The following Lex source is somewhat shorter than a previous Lex version.
Specifications assumed:  single blank lines, as well as runs of blank
lines +- <#> line directives, are to be replaced by <# lineno
"filename">; only truly blank lines (no space or tab) are to be
considered blank.  
------------------------------------------------------------------------
	char f[80];
%S P
%%
#.+\n	{sscanf(yytext,"#%d%s",&yylineno,f);BEGIN P;}
<P>.+\n	{printf("# %d %s\n",yylineno-1,f);ECHO;BEGIN 0;}
\n	BEGIN P;
.+\n	ECHO;
------------------------------------------------------------------------
John Rupley
rupley!local@megaron.arizona.edu