Module Zed_char

The type for glyphs.

To represent a grapheme in unicode is a bit more complicated than what is expected: a printable UChar. For example, diacritics are added to IPA(international phonetic alphabet) letter to produce a modified pronunciation. Variation selectors are added to a CJK character to specify a specific glyph variant for the character.

Therefore the logical type definition of Zed_char.t can be seen as

type Zed_char.t= {
  core: UChar.t;
  combined: UChar.t list;
}

core char returns the core of the char

combined char returns the combining marks of the char

unsafe_of_utf8 str returns a zed_char from utf8 encoded str without any validation.

of_utf8 str returns a zed_char from utf8 encoded str. This function checks whether str represents a single UChar or a legal grapheme, i.e. a printable core with optional combining marks. It will raise Failure "malformed Zed_char sequence" If the validation is not passed.

parameter indv_combining

allow to create a Zed_char.t from a single combining mark, default to true

to_utf8 chr converts a chr to a string encoded in UTF-8.

The Character 0.

prop_uChar uChar returns the char_prop of uChar

prop ch returns the char_prop of ch

Returns whether a UChar.t is a printable character or not.

Returns whether a UChar.t is a printable character and its width is not zero.

Returns whether a UChar.t is a combining mark.

size ch returns the size (number of characters) of ch.

Aliase of size

width ch returns the width of ch.

out_of_range ch idx returns whether idx is out of range of ch.

get ch n returns the n-th character of ch.

get ch n returns an optional value of the n-th character of ch.

append ch cm append the combining mark cm to ch and returns it. If cm is not a combining mark, then the original ch is returned.

compare_core ch1 ch2 compares the core components of ch1 and ch2

compare_raw ch1 ch2 compares over the internal characters of ch1 and ch2 sequentially

Alias of compare_raw

mix_uChar chr uChar tries to append uChar to chr and returns Ok result. If uChar is not a combining mark, then an Error (Zed_char.t consists of uChar) is returned.

of_uChars uChars transforms uChars to a tuple. The first value is an optional Zed_char.t and the second is a list of remaining uChars. The optional Zed_char.t is either a legal grapheme(a core printable char with optinal combining marks) or a wrap for an arbitrary UChar.t. After that, all remaining uChars returned as the second value in the tuple.

parameter trim

trim leading combining marks before transforming, default to false

parameter indv_combining

create a Zed_char from an individual dissociated combining mark, default to true

zChars of_uChars uChars transforms uChars to a tuple. The first value is a list of Zed_char.t and the second is a list of remaining uChars.

parameter trim

trim leading combining marks before transforming, default to false

parameter indv_combining

create a Zed_char from an individual dissociated combining mark, default to true

for_all p zChar checks if all elements of zChar satisfy the predicate p.

iter f char applies f on all characters of char.

unsafe_of_char ch returns a Zed_char whose core is ch.

unsafe_of_uChar ch returns a Zed_char whose core is ch.

Converting between UnicodeString.Type and Zed_char.t