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Module Strmodule Str:
Regular expressions and high-level string processing
type regexp
The type of compiled regular expressions.
val regexp :
Compile a regular expression. The syntax for regular expressions
is the same as in Gnu Emacs. The special characters are
$^.*+?[] . The following constructs are recognized:
val regexp_case_fold :
Same as
regexp , but the compiled expression will match text
in a case-insensitive way: uppercase and lowercase letters will
be considered equivalent.val quote : Str.quote s returns a regexp string that matches exactly
s and nothing else.val regexp_string : Str.regexp_string s returns a regular expression
that matches exactly s and nothing else.val regexp_string_case_fold : Str.regexp_string_case_fold is similar to Str.regexp_string ,
but the regexp matches in a case-insensitive way.
val string_match : string_match r s start tests whether the characters in s
starting at position start match the regular expression r .
The first character of a string has position 0 , as usual.val search_forward : search_forward r s start searchs the string s for a substring
matching the regular expression r . The search starts at position
start and proceeds towards the end of the string.
Return the position of the first character of the matched
substring, or raise Not_found if no substring matches.val search_backward :
Same as
Str.search_forward , but the search proceeds towards the
beginning of the string.val string_partial_match :
Similar to
Str.string_match , but succeeds whenever the argument
string is a prefix of a string that matches. This includes
the case of a true complete match.val matched_string : matched_string s returns the substring of s that was matched
by the latest Str.string_match , Str.search_forward or
Str.search_backward .
The user must make sure that the parameter s is the same string
that was passed to the matching or searching function.val match_beginning : match_beginning() returns the position of the first character
of the substring that was matched by Str.string_match ,
Str.search_forward or Str.search_backward .val match_end : match_end() returns the position of the character following the
last character of the substring that was matched by string_match ,
search_forward or search_backward .val matched_group : matched_group n s returns the substring of s that was matched
by the n th group \(...\) of the regular expression during
the latest Str.string_match , Str.search_forward or
Str.search_backward .
The user must make sure that the parameter s is the same string
that was passed to the matching or searching function.
matched_group n s raises Not_found if the n th group
of the regular expression was not matched. This can happen
with groups inside alternatives \| , options ?
or repetitions * . For instance, the empty string will match
\(a\)* , but matched_group 1 "" will raise Not_found
because the first group itself was not matched.val group_beginning : group_beginning n returns the position of the first character
of the substring that was matched by the n th group of
the regular expression.Raises Not_found if the n th group of the regular expression
was not matched.val group_end : group_end n returns
the position of the character following the last character of
substring that was matched by the n th group of the regular expression.Raises Not_found if the n th group of the regular expression
was not matched.
val global_replace : global_replace regexp templ s returns a string identical to s ,
except that all substrings of s that match regexp have been
replaced by templ . The replacement template templ can contain
\1 , \2 , etc; these sequences will be replaced by the text
matched by the corresponding group in the regular expression.
\0 stands for the text matched by the whole regular expression.val replace_first :
Same as
Str.global_replace , except that only the first substring
matching the regular expression is replaced.val global_substitute : global_substitute regexp subst s returns a string identical
to s , except that all substrings of s that match regexp
have been replaced by the result of function subst . The
function subst is called once for each matching substring,
and receives s (the whole text) as argument.val substitute_first :
Same as
Str.global_substitute , except that only the first substring
matching the regular expression is replaced.val replace_matched : replace_matched repl s returns the replacement text repl
in which \1 , \2 , etc. have been replaced by the text
matched by the corresponding groups in the most recent matching
operation. s must be the same string that was matched during
this matching operation.
val split : split r s splits s into substrings, taking as delimiters
the substrings that match r , and returns the list of substrings.
For instance, split (regexp "[ \t]+") s splits s into
blank-separated words. An occurrence of the delimiter at the
beginning and at the end of the string is ignored.val bounded_split :
val split_delim :
Same as
Str.split but occurrences of the
delimiter at the beginning and at the end of the string are
recognized and returned as empty strings in the result.
For instance, split_delim (regexp " ") " abc "
returns [""; "abc"; ""] , while split with the same
arguments returns ["abc"] .val bounded_split_delim :
Same as
Str.bounded_split , but occurrences of the
delimiter at the beginning and at the end of the string are
recognized and returned as empty strings in the result.
For instance, split_delim (regexp " ") " abc "
returns [""; "abc"; ""] , while split with the same
arguments returns ["abc"] .type split_result =
val full_split :
Same as
Str.split_delim , but returns
the delimiters as well as the substrings contained between
delimiters. The former are tagged Delim in the result list;
the latter are tagged Text . For instance,
full_split (regexp "[{}]") "{ab}" returns
[Delim "{"; Text "ab"; Delim "}"] .val bounded_full_split :
Same as
Str.bounded_split_delim , but returns
the delimiters as well as the substrings contained between
delimiters. The former are tagged Delim in the result list;
the latter are tagged Text . For instance,
full_split (regexp "[{}]") "{ab}" returns
[Delim "{"; Text "ab"; Delim "}"] .
val string_before : string_before s n returns the substring of all characters of s
that precede position n (excluding the character at
position n ).val string_after : string_after s n returns the substring of all characters of s
that follow position n (including the character at
position n ).val first_chars : first_chars s n returns the first n characters of s .
This is the same function as Str.string_before .val last_chars : last_chars s n returns the last n characters of s . |