Function utf16CodeUnitSequenceLength [src]

Given the first code unit of a UTF-16 codepoint, returns a number 1-2 indicating the total length of the codepoint in UTF-16 code units. If this code unit does not match the form of a UTF-16 start code unit, returns Utf16InvalidStartCodeUnit.

Prototype

pub fn utf16CodeUnitSequenceLength(first_code_unit: u16) !u2

Parameters

first_code_unit: u16

Example

 test utf16CodeUnitSequenceLength {
    try testing.expectEqual(@as(u2, 1), try utf16CodeUnitSequenceLength('a'));
    try testing.expectEqual(@as(u2, 1), try utf16CodeUnitSequenceLength(0xFFFF));
    try testing.expectEqual(@as(u2, 2), try utf16CodeUnitSequenceLength(0xDBFF));
    try testing.expectError(error.Utf16InvalidStartCodeUnit, utf16CodeUnitSequenceLength(0xDFFF));
}

Source

  pub fn utf16CodeUnitSequenceLength(first_code_unit: u16) !u2 {
    if (utf16IsHighSurrogate(first_code_unit)) return 2;
    if (utf16IsLowSurrogate(first_code_unit)) return error.Utf16InvalidStartCodeUnit;
    return 1;
}  