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Trivial UTF-8 Manual

Table of Contents

• 1 The trivial-utf-8 ASDF System
• 2 Introduction
• 3 Links
• 4 Reference

[in package TRIVIAL-UTF-8]

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1 The trivial-utf-8 ASDF System

• Description: A small library for doing UTF-8-based input and output.
• Licence: ZLIB
• Author: Marijn Haverbeke mailto:marijnh@gmail.com
• Maintainer: Gábor Melis mailto:mega@retes.hu
• Homepage: https://common-lisp.net/project/trivial-utf-8/
• Bug tracker: https://gitlab.common-lisp.net/trivial-utf-8/trivial-utf-8/-/issues
• Source control: GIT

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2 Introduction

Trivial UTF-8 is a small library for doing UTF-8-based in- and output on a Lisp implementation that already supports Unicode - meaning char-code and code-char deal with Unicode character codes.

The rationale for the existence of this library is that while Unicode-enabled implementations usually do provide some kind of interface to dealing with character encodings, these are typically not terribly flexible or uniform.

The Babel library solves a similar problem while understanding more encodings. Trivial UTF-8 was written before Babel existed, but for new projects you might be better off going with Babel. The one plus that Trivial UTF-8 has is that it doesn't depend on any other libraries.

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3 Links

Here is the official repository and the HTML documentation for the latest version.

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4 Reference

• [function] utf-8-byte-length string

  Calculate the amount of bytes needed to encode string.

• [function] string-to-utf-8-bytes string &key null-terminate

  Convert string into an array of unsigned bytes containing its UTF-8 representation. If null-terminate, add an extra 0 byte at the end.

• [function] utf-8-group-size byte

  Determine the amount of bytes that are part of the character whose encoding starts with byte. May signal utf-8-decoding-error.

• [function] utf-8-bytes-to-string bytes &key (start 0) (end (length bytes))

  Convert the start, end subsequence of the array of bytes containing UTF-8 encoded characters to a string. The element type of bytes may be anything as long as it can be coerced into an (unsigned-bytes 8) array. May signal utf-8-decoding-error.

• [function] read-utf-8-string input &key null-terminated stop-at-eof (char-length -1) (byte-length -1)

  Read UTF-8 encoded data from input, a byte stream, and construct a string with the characters found. When null-terminated is given, stop reading at a null character. If stop-at-eof, then stop at end-of-file without raising an error. The char-length and byte-length parameters can be used to specify the max amount of characters or bytes to read, where -1 means no limit. May signal utf-8-decoding-error.

• [condition] utf-8-decoding-error simple-error