steve
/
factor
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Documenting character class operations

db4
Daniel Ehrenberg 2009-03-21 03:22:50 -05:00
parent 4f83e2057a
commit 62c2ee8d3b
1 changed files with 2 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
basis/regexp/regexp-docs.factor
View File

@ -76,6 +76,8 @@ ARTICLE: { "regexp" "syntax" } "Regular expression syntax"
{ { $snippet "\\p{Nd}" } "Character in Unicode category Nd" }
{ { $snippet "\\p{Z}" } "Character in Unicode category beginning with Z" }
{ { $snippet "\\p{script=Cham}" } "Character in the Cham writing system" } }
{ $heading "Character class operations" }
"Character classes can be composed using four binary operations: " { $snippet "|| && ~~ --" } ". These do the operations union, intersection, symmetric difference and difference, respectively. For example, characters which are lower-case but not Latin script could be matched as " { $snippet "[\\p{lower}--\\p{script=latin}]" } ". These operations are right-associative, and " { $snippet "^" } " binds tighter than them. There is no syntax for grouping."
{ $heading "Boundaries" }
"Special operators exist to match certain points in the string. These are called 'zero-width' because they do not consume any characters."
{ $table