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Re: run-time-compiled regexes
From: |
Hans-Bernhard Broeker |
Subject: |
Re: run-time-compiled regexes |
Date: |
Wed, 12 Feb 2003 10:04:21 +0100 (MET) |
On Tue, 11 Feb 2003, Sam Bishop wrote:
> I'm trying to scan simulation output files. These files declare in their
> preambles what separator is used throughout the rest of the file. Is
> there any way to plug the separator into the regular expressions used for
> scanning the rest of the file, on the fly?
Not using flex itself. You would have to override YY_INPUT, and have it
scan for the current separator character or string and replace it with a
special character (say, the default separator, or some non-ASCII char that
will never be in the actual file). This would be equivalent to making
yyin a pipe handle opened by the equivalent of
popen("sed -e 's/;/\x001/g' inputfile", "r");
Or you could do this pre-filtering step on the actual file, outside
your flex-based scanning application.
--
Hans-Bernhard Broeker (address@hidden)
Even if all the snow were burnt, ashes would remain.