Utf8.next

This is an iteration function to traverse each single codepoint of a UTF-8 string.

Syntax

int, int utf8.next ( string input [[, int charpos = 0 ], int offset = 1 ] )

Required Arguments

• input: A string character sequence

Optional Arguments

NOTE: When using optional arguments, you might need to supply all arguments before the one you wish to use. For more information on optional arguments, see optional arguments.

• charpos: An integer representing the beginning position (offset will be added/subtracted).
• offset: An integer representing the offset to charpos.

Returns

Returns the integer position in bytes and the integer codepoint at this position, nil otherwise.

Example

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Server

This example shows how to traverse a UTF-8 string the proper way without running into problems as in byte strings.

for position, codepoint in utf8.next, "utf8-string" do
    print( "Codepoint @ ".. position .." = ".. codepoint )
end

for position, codepoint in utf8.next, "Как" do
    print( "Codepoint @ ".. position .." = ".. codepoint )
end

Output:

// 1st iteration
Codepoint @ 1 = 117
Codepoint @ 2 = 116
Codepoint @ 3 = 102
Codepoint @ 4 = 56
Codepoint @ 5 = 45
Codepoint @ 6 = 115
Codepoint @ 7 = 116
Codepoint @ 8 = 114
Codepoint @ 9 = 105
Codepoint @ 10 = 110
Codepoint @ 11 = 103

// 2nd iteration
Codepoint @ 1 = 1050
Codepoint @ 3 = 1072
Codepoint @ 5 = 1082

See Also

• utf8.byte
• utf8.char
• utf8.charpos
• utf8.escape
• utf8.find
• utf8.fold
• utf8.gmatch
• utf8.gsub
• utf8.insert
• utf8.len
• utf8.lower
• utf8.match
• utf8.ncasecmp
• utf8.next
• utf8.remove
• utf8.reverse
• utf8.sub
• utf8.title
• utf8.upper
• utf8.width
• utf8.widthindex