# Module Xstr_search

    module Xstr_search: sig .. end

    exception Replace_phrase of (int * string)

see 'replace_char' and 'replace_string'

    val index_of_substring_from : string -> int -> string -> int

index_of_substring_from s k_left substr: finds the leftmost index >= k_left where 'substr' occurs within s or raises Not_found.

    val rindex_of_substring_from : string -> int -> string -> int

eindex_of_substring_from s k_right substr: finds the rightmost index <= k_right where 'substr' occurs within s or raises Not_found.

    val index_of_substring : string -> string -> int

index_of_substring s substr: finds the leftmost index where 'substr' occurs within s or raises Not_found.

    val rindex_of_substring : string -> string -> int

eindex_of_substring s substr: finds the rightmost index where 'substr' occurs within s or raises Not_found.

    val contains_substring : string -> string -> bool

contains_substring s substr: true iff substr occurs in s

    val contains_substring_from : string -> int -> string -> bool

contains_substring_from s k_left substr: true iff substr occurs in s at index k_left or later

    val rcontains_substring_from : string -> int -> string -> bool

rcontains_substring_from s k_right substr: true iff substr occurs in s at index k_right or earlier

    val indexlist_of_substring : string -> string -> int list

indexlist_of_substring s substr: Returns a list of all indexes of substrings substr in s

    val rev_concat : string -> string list -> string

rev_concat s l = String.concat s (List.rev l)

    val replace_char : string -> (char -> int -> string) -> string

replace_char s rule: replaces characters in s according to rule. rule c k = s' means: replace character c where c = s.`k` by s' The rule may raise Match_failure or Not_found in which case the character is not replaced. It may raise Replace_phrase (l,s') which means that the l characters at k should be replaced by s'.

EXAMPLE:

- replace '<', '>', '&' in an HTML document by CDATA entities: replace_char s (fun c k -> match c with '<' -> "&lt;" | '>' -> "&gt;" | '&' -> "&amp;" )
- replace backslashes by double-backslashes and precede quotes with backslashes: replace_char s (fun c k -> match c with '\\' -> "\\\\" '"' -> "\\\"")
- the reverse function (remove backslashes): replace_char s (fun c k -> match c with '\\' -> begin if k+1 < String.length s then raise (Replace_phrase (2, String.make 1 (s.`k+1`))) else raise Not_found end)

    val replace_substring : string -> string list -> (string -> int -> string) -> string

replace_substring s substrlist rule: replaces all occurences of substrings in 's' which are enumerated in 'substrlist' by applying 'rule'. rule t k = t': means that substring t at position k is replaced by t' The rule may raise Match_failure or Not_found in which case the character is not replaced. It may raise Replace_phrase (l,s') which means that the l characters at k should be replaced by s'.

EXAMPLE:

- Interpret CDATA entities of HTML: replace_substring s `"&lt;"; "&gt;"; "&amp;"` (fun s k -> match s with "&lt;" -> "<" | "&gt;" -> ">" | "&amp;" -> "&")