Module String

module String: sig .. end

Extensions to Core.Core_String .

val collate : string -> string -> int

collate s1 s2 sorts string in an order that's is usaully more suited for human consumption by treating ints specificaly: (e.g. it will output: ["rfc1.txt";"rfc822.txt";"rfc2086.txt"]).

It works by splitting the strings in numerical and non numerical chunks and comparing chunks two by two from left to right (and starting on a non numerical chunks):

• Non_numerical chunks are compared using lexicographical ordering.
• Numerical chunks are compared based on the values of the represented ints and the number of trailing zeros.

It is a total order.

val unescaped : ?strict:bool -> string -> string

unescaped s is the inverse operation of escaped: it takes a string where all the special characters are escaped following the lexical convention of OCaml and returns an unescaped copy. The strict switch is on by default and makes the function treat illegal backslashes as errors. When strict is false every illegal backslash except escaped numeral greater than 255 is copied literally. The aforementioned numerals still raise errors. This mimics the behaviour of the ocaml lexer.

val unescaped_res : ?strict:bool -> string -> (string, int * string) Core.Result.t

Same as unescaped but instead of raising Failure _ returns an error message with the position in the string in case of failure.

val squeeze : string -> string

squeeze str reduces all sequences of spaces, newlines, tables, and * carriage returns to single spaces.

val is_substring : substring:string -> string -> bool

is_substring ~substring t returns true if substring is a substring * of t.

val pad_left : ?char:char -> string -> int -> string

pad_left ~char s len Returns s padded to the length len by adding characters char to the left of the string. If s is already longer than len it is returned unchanged.

val pad_right : ?char:char -> string -> int -> string

val line_break : len:int -> string -> string list

deprecated in favour of word_wrap

val word_wrap : ?trailing_nl:bool ->
       ?soft_limit:int -> ?hard_limit:int -> ?nl:string -> string -> string

word_wrap ~soft_limit s

Wraps the string so that it fits the length soft_limit. It doesn't break words unless we go over hard_limit.

if nl is passed it is inserted instead of the normal newline character.

val consolidate_strings : ?int_sets:[ `Asterisk | `Bounds | `Exact ] -> string list -> string

Consolidates a list of strings (almost ^) losslessly. E.g.:

abc-def-1-ghijk abc-def-2-ghijk abc-def-5-ghijk abc-xyz-2 abc-xyz-3

becomes:

abc-

The algorithm is conceptually as follows: 1) if all strings are sequences of digits, return contiguous subranges , otherwise: 2) split all strings into groups of consecutive letters or digits (but not both) 3) break the list into sublists by the 1st and last token (1st token has precedence) 4) for each sublist, find the longest prefix and suffix common for all entries 5) replace each sublist with: "common_prefix-<result_of_the_recursive_call>-common_suffix" 6) return String.concat ~sep:"," <compressed_sublists>

In the implementation, we only tokenize the strings once, and then recursively work with lists of tokens.

^ Repeated entries and the original ordering of the list are not preserved. Otherwise, this transformation is lossless.

Additionally, one may choose to represent sets of integers as the lower..upper bound (so 1-2,5 becomes 1..5), or just by an asterisk ("*"), when brevity is preferred over accuracy.

^ Repeated entries and the original ordering of the list are not preserved. Otherwise, this transformation is lossless.

val consolidate_strings' : max_len:int -> string list -> string

Consolidates a list of strings in such a way that the result does not exceed the given length. Tries the following, in order:

1) plain consolidate_strings 2) consolidate_strings ~int_sets:`Bounds 3) consolidate_strings ~int_sets:`Asterisk 4) prefix of 3 ^ "..."

val edit_distance : ?transpose:unit -> string -> string -> int

Gives the Levenshtein distance between 2 strings, which is the number of insertions, deletions, and substitutions necessary to turn either string into the other. With the transpose argument, it alsos considers transpositions (Damerau-Levenshtein distance).