Portability | portable |
---|---|
Stability | stable |
Maintainer | Uwe Schmidt <uwe@fh-wedel.de> |
Safe Haskell | Safe-Inferred |
Convenient functions for W3C XML Schema Regular Expression Matcher.
For internals see Regex
and
Matching
Grammar can be found under http://www.w3.org/TR/xmlschema11-2/#regexs
- data GenRegex s
- type Regex = GenRegex String
- type RegexText = GenRegex Text
- type RegexTextLazy = GenRegex Text
- type RegexByteString = GenRegex ByteString
- type RegexByteStringLazy = GenRegex ByteString
- grep :: StringLike s => s -> [s] -> [s]
- grepExt :: StringLike s => s -> [s] -> [s]
- grepRE :: StringLike s => GenRegex s -> [s] -> [s]
- grepREwithLineNum :: StringLike s => GenRegex s -> [s] -> [(Int, s)]
- match :: StringLike s => s -> s -> Bool
- matchExt :: StringLike s => s -> s -> Bool
- matchSubex :: StringLike s => s -> s -> [(s, s)]
- sed :: StringLike s => (s -> s) -> s -> s -> s
- sedExt :: StringLike s => (s -> s) -> s -> s -> s
- split :: StringLike s => s -> s -> (s, s)
- splitExt :: StringLike s => s -> s -> (s, s)
- splitSubex :: StringLike s => s -> s -> ([(s, s)], s)
- tokenize :: StringLike s => s -> s -> [s]
- tokenizeExt :: StringLike s => s -> s -> [s]
- tokenize' :: StringLike s => s -> s -> [Either s s]
- tokenizeExt' :: StringLike s => s -> s -> [Either s s]
- tokenizeSubex :: StringLike s => s -> s -> [(s, s)]
- matchRE :: StringLike s => GenRegex s -> s -> Bool
- matchSubexRE :: StringLike s => GenRegex s -> s -> [(s, s)]
- sedRE :: StringLike s => (s -> s) -> GenRegex s -> s -> s
- splitRE :: StringLike s => GenRegex s -> s -> Maybe (s, s)
- splitSubexRE :: StringLike s => GenRegex s -> s -> Maybe ([(s, s)], s)
- tokenizeRE :: StringLike s => GenRegex s -> s -> [s]
- tokenizeRE' :: StringLike s => GenRegex s -> s -> [Either s s]
- tokenizeSubexRE :: StringLike s => GenRegex s -> s -> [(s, s)]
- mkZero :: s -> GenRegex s
- mkZero' :: StringLike s => String -> GenRegex s
- mkUnit :: GenRegex s
- mkSym1 :: StringLike s => Char -> GenRegex s
- mkSymRng :: StringLike s => Char -> Char -> GenRegex s
- mkWord :: StringLike s => [Char] -> GenRegex s
- mkDot :: GenRegex s
- mkStar :: StringLike s => GenRegex s -> GenRegex s
- mkAll :: StringLike s => GenRegex s
- mkAlt :: StringLike s => GenRegex s -> GenRegex s -> GenRegex s
- mkElse :: StringLike s => GenRegex s -> GenRegex s -> GenRegex s
- mkSeq :: GenRegex s -> GenRegex s -> GenRegex s
- mkSeqs :: [GenRegex s] -> GenRegex s
- mkRep :: StringLike s => Int -> GenRegex s -> GenRegex s
- mkRng :: StringLike s => Int -> Int -> GenRegex s -> GenRegex s
- mkOpt :: StringLike s => GenRegex s -> GenRegex s
- mkDiff :: StringLike s => GenRegex s -> GenRegex s -> GenRegex s
- mkIsect :: StringLike s => GenRegex s -> GenRegex s -> GenRegex s
- mkExor :: StringLike s => GenRegex s -> GenRegex s -> GenRegex s
- mkCompl :: StringLike s => GenRegex s -> GenRegex s
- mkBr :: s -> GenRegex s -> GenRegex s
- mkBr' :: StringLike s => String -> GenRegex s -> GenRegex s
- isZero :: GenRegex s -> Bool
- errRegex :: StringLike s => GenRegex s -> s
- parseRegex :: StringLike s => s -> GenRegex s
- parseRegexExt :: StringLike s => s -> GenRegex s
- parseContextRegex :: StringLike s => (String -> GenRegex s) -> s -> GenRegex s
Documentation
Eq s => Eq (GenRegex s) | |
Ord s => Ord (GenRegex s) | |
StringLike s => Show (GenRegex s) |
type RegexTextLazy = GenRegex TextSource
type RegexByteString = GenRegex ByteStringSource
type RegexByteStringLazy = GenRegex ByteStringSource
grep :: StringLike s => s -> [s] -> [s]Source
grep like filter for lists of strings
The regular expression may be prefixed with the usual context spec "^" for start of string, and \< for start of word. and suffixed with "$" for end of text and \> end of word. Word chars are defined by the multi char escape sequence \w
Examples
grep "a" ["_a_", "_a", "a_", "a", "_"] => ["_a_", "_a", "a_", "a"] grep "^a" ["_a_", "_a", "a_", "a", "_"] => ["a_", "a"] grep "a$" ["_a_", "_a", "a_", "a", "_"] => ["_a", "a"] grep "^a$" ["_a_", "_a", "a_", "a", "_"] => ["a"] grep "\\<a" ["x a b", " ax ", " xa ", "xab"] => ["x a b", " ax "] grep "a\\>" ["x a b", " ax ", " xa ", "xab"] => ["x a b", " xa "]
grepExt :: StringLike s => s -> [s] -> [s]Source
grep with extended regular expressions
grepRE :: StringLike s => GenRegex s -> [s] -> [s]Source
grep with already prepared Regex (ususally with parseContextRegex
)
grepREwithLineNum :: StringLike s => GenRegex s -> [s] -> [(Int, s)]Source
grep with Regex and line numbers
match :: StringLike s => s -> s -> BoolSource
convenient function for matchRE
Examples:
match "x*" "xxx" = True match "x" "xxx" = False match "[" "xxx" = False
matchExt :: StringLike s => s -> s -> BoolSource
match with extended regular expressions
matchSubex :: StringLike s => s -> s -> [(s, s)]Source
convenient function for matchRE
Examples:
matchSubex "({1}x*)" "xxx" = [("1","xxx")] matchSubex "({1}x*)" "y" = [] matchSubex "({w}[0-9]+)x({h}[0-9]+)" "800x600" = [("w","800"),("h","600")] matchSubex "[" "xxx" = []
sed :: StringLike s => (s -> s) -> s -> s -> sSource
convenient function for sedRE
examples:
sed (const "b") "a" "xaxax" = "xbxbx" sed (\ x -> x ++ x) "a" "xax" = "xaax" sed undefined "[" "xxx" = "xxx"
sedExt :: StringLike s => (s -> s) -> s -> s -> sSource
split :: StringLike s => s -> s -> (s, s)Source
convenient function for splitRE
examples:
split "a*b" "abc" = ("ab","c") split "a*" "bc" = ("", "bc") -- "a*" matches "" split "a+" "bc" = ("", "bc") -- "a+" does not match, no split split "[" "abc" = ("", "abc") -- "[" syntax error, no split
splitExt :: StringLike s => s -> s -> (s, s)Source
split with extended syntax
splitSubex :: StringLike s => s -> s -> ([(s, s)], s)Source
convenient function for splitSubex
, uses extended syntax
examples:
splitSubex "({1}a*)b" "abc" = ([("1","a")],"c") splitSubex "({2}a*)" "bc" = ([("2","")], "bc") splitSubex "({1}a|b)+" "abc" = ([("1","a"),("1","b")],"c") -- subex 1 matches 2 times splitSubex ".*({x}a*)" "aa" = ([("x",""),("x","a"),("x","aa")],"") -- nondeterminism: 3 matches for a* splitSubex "({1}do)|({2}[a-z]+)" "do you know" = ([("1","do"),("2","do")]," you know") -- nondeterminism: 2 matches for do splitSubex "({1}do){|}({2}[a-z]+)" "do you know" = ([("1","do")]," you know") -- no nondeterminism with {|}: 1. match for do splitSubex "({1}a+)" "bcd" = ([], "bcd") -- no match splitSubex "[" "abc" = ([], "abc") -- syntax error
tokenize :: StringLike s => s -> s -> [s]Source
split a string into tokens (words) by giving a regular expression which all tokens must match.
Convenient function for tokenizeRE
This can be used for simple tokenizers.
It is recommended to use regular expressions where the empty word does not match.
Else there will appear a lot of probably useless empty tokens in the output.
All none matching chars are discarded. If the given regex contains syntax errors,
Nothing
is returned
examples:
tokenize "a" "aabba" = ["a","a","a"] tokenize "a*" "aaaba" = ["aaa","a"] tokenize "a*" "bbb" = ["","",""] tokenize "a+" "bbb" = [] tokenize "a*b" "" = [] tokenize "a*b" "abc" = ["ab"] tokenize "a*b" "abaab ab" = ["ab","aab","ab"] tokenize "[a-z]{2,}|[0-9]{2,}|[0-9]+[.][0-9]+" "ab123 456.7abc" = ["ab","123","456.7","abc"] tokenize "[a-z]*|[0-9]{2,}|[0-9]+[.][0-9]+" "cab123 456.7abc" = ["cab","123","456.7","abc"] tokenize "[^ \t\n\r]*" "abc def\t\n\rxyz" = ["abc","def","xyz"] tokenize ".*" "\nabc\n123\n\nxyz\n" = ["","abc","123","","xyz"] tokenize ".*" = lines tokenize "[^ \t\n\r]*" = words
tokenizeExt :: StringLike s => s -> s -> [s]Source
tokenize with extended syntax
tokenize' :: StringLike s => s -> s -> [Either s s]Source
convenient function for tokenizeRE'
When the regular expression parses as Zero, [Left input]
is returned, that means no tokens are found
tokenizeExt' :: StringLike s => s -> s -> [Either s s]Source
tokenizeSubex :: StringLike s => s -> s -> [(s, s)]Source
convenient function for tokenizeSubexRE
a string
examples:
tokenizeSubex "({name}[a-z]+)|({num}[0-9]{2,})|({real}[0-9]+[.][0-9]+)" "cab123 456.7abc" = [("name","cab") ,("num","123") ,("real","456.7") ,("name","abc")] tokenizeSubex "({real}({n}[0-9]+)([.]({f}[0-9]+))?)" "12.34" = [("real","12.34") ,("n","12") ,("f","34")] tokenizeSubex "({real}({n}[0-9]+)([.]({f}[0-9]+))?)" "12 34" = [("real","12"),("n","12") ,("real","34"),("n","34")] tokenizeSubex "({real}({n}[0-9]+)(([.]({f}[0-9]+))|({f})))" "12 34.56" = [("real","12"),("n","12"),("f","") ,("real","34.56"),("n","34"),("f","56")]
matchRE :: StringLike s => GenRegex s -> s -> BoolSource
match a string with a regular expression
matchSubexRE :: StringLike s => GenRegex s -> s -> [(s, s)]Source
match a string with a regular expression and extract subexpression matches
sedRE :: StringLike s => (s -> s) -> GenRegex s -> s -> sSource
sed like editing function
All matching tokens are edited by the 1. argument, the editing function, all other chars remain as they are
splitRE :: StringLike s => GenRegex s -> s -> Maybe (s, s)Source
split a string by taking the longest prefix matching a regular expression
Nothing
is returned in case there is no matching prefix,
else the pair of prefix and rest is returned
splitSubexRE :: StringLike s => GenRegex s -> s -> Maybe ([(s, s)], s)Source
split a string by removing the longest prefix matching a regular expression and then return the list of subexpressions found in the matching part
Nothing
is returned in case of no matching prefix,
else the list of pairs of labels and submatches and the
rest is returned
tokenizeRE :: StringLike s => GenRegex s -> s -> [s]Source
The function, that does the real work for tokenize
tokenizeRE' :: StringLike s => GenRegex s -> s -> [Either s s]Source
split a string into tokens and delimierter by giving a regular expression which all tokens must match
This is a generalisation of the above tokenizeRE
functions.
The none matching char sequences are marked with Left
, the matching ones are marked with Right
If the regular expression contains syntax errors Nothing
is returned
The following Law holds:
concat . map (either id id) . tokenizeRE' re == id
tokenizeSubexRE :: StringLike s => GenRegex s -> s -> [(s, s)]Source
split a string into tokens (pair of labels and words) by giving a regular expression containing labeled subexpressions.
This function should not be called with regular expressions without any labeled subexpressions. This does not make sense, because the result list will always be empty.
Result is the list of matching subexpressions
This can be used for simple tokenizers.
At least one char is consumed by parsing a token.
The pairs in the result list contain the matching substrings.
All none matching chars are discarded. If the given regex contains syntax errors,
Nothing
is returned
mkZero :: s -> GenRegex sSource
construct the r.e. for the empty set. An (error-) message may be attached
mkZero' :: StringLike s => String -> GenRegex sSource
mkSym1 :: StringLike s => Char -> GenRegex sSource
construct an r.e. for a single char set
mkSymRng :: StringLike s => Char -> Char -> GenRegex sSource
construct an r.e. for an intervall of chars
mkWord :: StringLike s => [Char] -> GenRegex sSource
mkSym generaized for strings
mkStar :: StringLike s => GenRegex s -> GenRegex sSource
construct r.e. for r*
mkAll :: StringLike s => GenRegex sSource
construct an r.e. for the set of all Unicode words
mkElse :: StringLike s => GenRegex s -> GenRegex s -> GenRegex sSource
construct the r.e. for r1{|}r2 (r1 orElse r2).
This represents the same r.e. as r1|r2, but when collecting the results of subexpressions in (...) and r1 succeeds, the subexpressions of r2 are discarded, so r1 matches are prioritized
example
splitSubex "({1}x)|({2}.)" "x" = ([("1","x"),("2","x")], "") splitSubex "({1}x){|}({2}.)" "x" = ([("1","x")], "")
mkRep :: StringLike s => Int -> GenRegex s -> GenRegex sSource
Construct repetition r{i,}
mkRng :: StringLike s => Int -> Int -> GenRegex s -> GenRegex sSource
Construct range r{i,j}
mkOpt :: StringLike s => GenRegex s -> GenRegex sSource
Construct option r?
mkDiff :: StringLike s => GenRegex s -> GenRegex s -> GenRegex sSource
Construct difference r.e.: r1 {\} r2
example
match "[a-z]+{\\}bush" "obama" = True match "[a-z]+{\\}bush" "clinton" = True match "[a-z]+{\\}bush" "bush" = False -- not important any more
mkIsect :: StringLike s => GenRegex s -> GenRegex s -> GenRegex sSource
Construct r.e. for intersection: r1 {&} r2
example
match ".*a.*{&}.*b.*" "-a-b-" = True match ".*a.*{&}.*b.*" "-b-a-" = True match ".*a.*{&}.*b.*" "-a-a-" = False match ".*a.*{&}.*b.*" "---b-" = False
mkExor :: StringLike s => GenRegex s -> GenRegex s -> GenRegex sSource
Construct r.e. for exclusive or: r1 {^} r2
example
match "[a-c]+{^}[c-d]+" "abc" = True match "[a-c]+{^}[c-d]+" "acdc" = False match "[a-c]+{^}[c-d]+" "ccc" = False match "[a-c]+{^}[c-d]+" "cdc" = True
mkCompl :: StringLike s => GenRegex s -> GenRegex sSource
Construct the Complement of an r.e.: whole set of words - r
mkBr' :: StringLike s => String -> GenRegex s -> GenRegex sSource
errRegex :: StringLike s => GenRegex s -> sSource
parseRegex :: StringLike s => s -> GenRegex sSource
parse a standard W3C XML Schema regular expression
parseRegexExt :: StringLike s => s -> GenRegex sSource
parse an extended syntax W3C XML Schema regular expression
The Syntax of the W3C XML Schema spec is extended by
further useful set operations, like intersection, difference, exor.
Subexpression match becomes possible with "named" pairs of parentheses.
The multi char escape sequence \a represents any Unicode char,
The multi char escape sequence \A represents any Unicode word, (\A = \a*).
All syntactically wrong inputs are mapped to the Zero expression representing the
empty set of words. Zero contains as data field a string for an error message.
So error checking after parsing becomes possible by checking against Zero (isZero
predicate)
parseContextRegex :: StringLike s => (String -> GenRegex s) -> s -> GenRegex sSource
parse a regular expression surrounded by contenxt spec
a leading ^
denotes start of text,
a trailing $
denotes end of text,
a leading \<
denotes word start,
a trailing \>
denotes word end.
The 1. param ist the regex parser (parseRegex
or parseRegexExt
)