Re: [Chicken-users] Why no PCRE for Windows?

[John Cowan]

Kon Lovett scripsit:

> >  PCRE_CASELESS        1 ; treat uppercase like lowercase
> >  PCRE_MULTILINE       2 ; limit search at a newline like Perl's /m
> >  PCRE_DOTALL          4 ; . (dot) also matches newline
> >  PCRE_EXTENDED        8 ; ignore whitespace except inside char class
> >  PCRE_ANCHORED       16 ; anchor at the start
> >  PCRE_DOLLAR_ENDONLY 32 ; $ matches at end of string, not before  
> >newline
> >  PCRE_EXTRA          64 ; additional functionality currently not used
> >  PCRE_NOTBOL        128 ; first char not start of line, ^  
> >shouldn't match
> >  PCRE_NOTEOL        256 ; last char not end of line, $ shouldn't  
> >match
> >  PCRE_UNGREEDY      512 ; invert greediness of quantifiers
> >  PCRE_NOTEMPTY     1024 ; empty string considered invalid
> >  PCRE_UTF8         2048 ; pattern and strings as UTF-8 characters

Some of these things can be triggered by "(?x)" at the start of the regex,
where x is a lowercase letter.  In particular, "(?i)" forces case-blind
matching, "(?s)" forces dot to match newline, "(?x)" forces whitespace
to be ignored, and "(?m)" forces ^ and $ to match around newlines,
not just at the beginning/end of the string.  (\A and \Z match the
beginning and end of string respectively independent of this flag,
so you can get the effect of PCRE_ANCHORED by wrapping your pattern
with them.)

-- 
John Cowan    http://ccil.org/~cowan    address@hidden
[T]here is a Darwinian explanation for the refusal to accept Darwin.
Given the very pessimistic conclusions about moral purpose to which his
theory drives us, and given the importance of a sense of moral purpose
in helping us cope with life, a refusal to believe Darwin's theory may
have important survival value. --Ian Johnston