module Zed_utf8

check str checks that str is a valid UTF-8 encoded string.

Same as check but raises an exception in case the argument is not a valid text, otherwise returns the length of the string.

next_error str ofs returns (ofs', count, msg) where ofs' is the offset of the start of the first invalid sequence after ofs (inclusive) in str, count is the number of unicode character between ofs and ofs' (exclusive) and msg is an error message. If there is no error until the end of string then ofs is String.length str and msg is the empty string.

singleton ch creates a string of length 1 containing only the given character.

make n ch creates a string of length n filled with ch.

init n f returns the contenation of singleton (f 0), singleton (f 1), ..., singleton (f (n - 1)).

rev_init n f returns the contenation of singleton (f (n - 1)), ..., singleton (f 1), singleton (f 0).

Returns the length of the given string.

Compares two strings (in code point order).

get str idx returns the character at index idx in str.

sub str ofs len Returns the sub-string of str starting at ofs and of length len.

break str pos returns the sub-strings before and after pos in str. It is more efficient than creating two sub-strings with sub.

before str pos returns the sub-string before pos in str

after str pos returns the sub-string after pos in str

insert str pos sub inserts sub in str at position pos.

remove str pos len removes the len characters at position pos in str

replace str pos len repl replaces the len characters at position pos in str by repl.

rev str reverses all characters of str.

concat sep l returns the concatenation of all strings of l separated by sep.

concat sep l returns the concatenation of all strings of l in reverse order separated by sep.

explode str returns the list of all characters of str.

rev_explode str returns the list of all characters of str in reverse order.

implode l returns the concatenation of all characters of l.

rev_implode l is the same as implode (List.rev l) but more efficient.

iter f str applies f an all characters of str starting from the left.

rev_iter f str applies f an all characters of str starting from the right.

fold f str acc applies f on all characters of str starting from the left, accumulating a value.

rev_fold f str acc applies f on all characters of str starting from the right, accumulating a value.

map f str maps all characters of str with f.

rev_map f str maps all characters of str with f in reverse order.

map f str maps all characters of str with f and concatenate the result.

rev_map f str maps all characters of str with f in reverse order and concatenate the result.

filter f str filters characters of str with f.

rev_filter f str filters characters of str with f in reverse order.

filter_map f str filters and maps characters of str with f.

rev_filter_map f str filters and maps characters of str with f in reverse order.

filter_map f str filters and maps characters of str with f and concatenate the result.

rev_filter_map f str filters and maps characters of str with f in reverse order and concatenate the result.

for_all f text returns whether all characters of text verify the predicate f.

exists f text returns whether at least one character of text verify f.

count f text returhs the number of characters of text verifying f.

contains text sub returns whether sub appears in text

starts_with text prefix returns true iff s starts with prefix.

ends_with text suffix returns true iff s ends with suffix.

strip ?predicate text returns text without its firsts and lasts characters that match predicate. predicate default to testing whether the given character has the `White_Space unicode property. For example:

        strip "\n  foo\n  " = "foo"

lstrip ?predicate text is the same as strip but it only removes characters at the left of text.

lstrip ?predicate text is the same as strip but it only removes characters at the right of text.

lchop t returns t without is first character. Returns "" if t = ""

rchop t returns t without is last character. Returns "" if t = "".

add buf ch is the same as Buffer.add_string buf (singleton ch) but is more efficient.

escaped_char ch returns a string containg ch or an escaped version of ch if:

• ch is a control character (code < 32)
• ch is the character with code 127
• ch is a non-ascii, non-alphabetic character

It uses the syntax \xXX, \uXXXX, \UXXXXXX or a specific escape sequence \n, \r, ....

add_escaped_char buf ch is the same as Buffer.add_string buf (escaped_char ch) but a bit more efficient.

escaped text escape all characters of text as with escape_char.

add_escaped_char buf text is the same as Buffer.add_string buf (escaped text) but a bit more efficient.

escaped_string enc str escape the string str which is encoded with encoding enc. If decoding str with enc fails, it escape all non-printable bytes of str with the syntax \yAB.

add_escaped_char buf enc text is the same as Buffer.add_string buf (escaped_string enc text) but a bit more efficient.

next str ofs returns the offset of the next character in str.

prev str ofs returns the offset of the previous character in str.

extract str ofs returns the code-point at offset ofs in str.

extract_next str ofs returns the code-point at offset ofs in str and the offset the next character.

extract_prev str ofs returns the code-point at the previous offset in str and this offset.

unsafe_next str ofs returns the offset of the next character in str.

unsafe_prev str ofs returns the offset of the previous character in str.

unsafe_extract str ofs returns the code-point at offset ofs in str.

unsafe_extract_next str ofs returns the code-point at offset ofs in str and the offset the next character.

unsafe_extract_prev str ofs returns the code-point at the previous offset in str and this offset.