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Function std.utf.decode
Decodes and returns the code point starting at str[index]
. index
is advanced to one past the decoded code point. If the code point is not
well-formed, then a UTFException
is thrown and index
remains
unchanged.
dchar decode(Flag!("useReplacementDchar") useReplacementDchar = No .useReplacementDchar, S)
(
auto ref S str,
ref size_t index
)
if (!isSomeString!S && isRandomAccessRange!S && hasSlicing!S && hasLength!S && isSomeChar!(ElementType!S));
dchar decode(Flag!("useReplacementDchar") useReplacementDchar = No .useReplacementDchar, S)
(
auto ref S str,
ref size_t index
) pure @trusted
if (isSomeString!S);
decode will only work with strings and random access ranges of code units
with length and slicing, whereas decodeFront
will work with any
input range of code units.
Parameters
Name | Description |
---|---|
useReplacementDchar | if invalid UTF, return replacementDchar rather than throwing |
str | input string or indexable Range |
index | starting index into s[]; incremented by number of code units processed |
Returns
decoded character
Throws
UTFException
if str[index]
is not the start of a valid UTF
sequence and useReplacementDchar is No
Example
size_t i;
assert("a" .decode(i) == 'a' && i == 1);
i = 0;
assert("å" .decode(i) == 'å' && i == 2);
i = 1;
assert("aå" .decode(i) == 'å' && i == 3);
i = 0;
assert("å"w .decode(i) == 'å' && i == 1);
// ë as a multi-code point grapheme
i = 0;
assert("e\u0308" .decode(i) == 'e' && i == 1);
// ë as a single code point grapheme
i = 0;
assert("ë" .decode(i) == 'ë' && i == 2);
i = 0;
assert("ë"w .decode(i) == 'ë' && i == 1);
Authors
License
Copyright © 1999-2022 by the D Language Foundation | Page generated by ddox.