Char is:module

The Char type and associated operations.

Warning: this is an internal module, and does not have a stable API or name. Functions in this module may not check or enforce preconditions expected by public modules. Use at your own risk! Fast character manipulation functions.

Commonly used character parsers.

Parsec compatibility module

Commonly used character parsers.

Utilities for working with KnownChar constraints. This module is only available on GHC 9.2 or later.

Parsers for character streams

Unicode Char. Import as:

import qualified RIO.Char as C

This module does not export any partial functions. For those, see RIO.Char.Partial

TextShow instances and monomorphic functions for Char and String. Since: 2

Access to the Unicode Character Database, implemented as bindings to the International Components for Unicode (ICU) libraries. Unicode assigns each codepoint (not just assigned character) values for many properties. Most are simple boolean flags, or constants from a small enumerated list. For some, values are relatively more complex types. For more information see "About the Unicode Character Database" http://www.unicode.org/ucd/ and the ICU User Guide chapter on Properties http://icu-project.org/userguide/properties.html.

A collection of character utilities, follows the namings in Data.Char and is intended to be imported qualified. Also, it is recommended you use the OverloadedStrings extension to allow literal strings to be used as symbolic-strings when working with symbolic characters and strings. SChar type only covers all unicode characters, following the specification in https://smt-lib.org/theories-UnicodeStrings.shtml. However, some of the recognizers only support the Latin1 subset, suffixed by L1. The reason for this is that there is no performant way of performing these functions for the entire unicode set. As SMTLib's capabilities increase, we will provide full unicode versions as well.

Agda strings uses Data.Text [1], which can only represent unicode scalar values [2], excluding the surrogate code points 3. To allow primStringFromList to be injective we make sure character values also exclude surrogate code points, mapping them to the replacement character U+FFFD. See #4999 for more information.

• 1 https://hackage.haskell.org/package/text-1.2.4.0/docs/Data-Text.html#g:2
• 2 https://www.unicode.org/glossary/#unicode_scalar_value
• 3 https://www.unicode.org/glossary/#surrogate_code_point

The Char type has 128 nullary constructors, listed in order according to each character's 7-bit numeric code.

This module provides APIs to access the Unicode character database (UCD) corresponding to Unicode Standard version 15.1.0. This module re-exports several sub-modules under it. The sub-module structure under Char is largely based on the "Property Index by Scope of Use" in Unicode® Standard Annex #44. The Unicode.Char.* modules in turn depend on Unicode.Internal.Char.* modules which are programmatically generated from the Unicode standard's Unicode character database files. The module structure under Unicode.Internal.Char is largely based on the UCD text file names from which the properties are generated. For the original UCD files used in this code please refer to the UCD section on the Unicode standard page. See https://www.unicode.org/reports/tr44/ to understand the contents and the format of the unicode database files.

Unicode character parsers. The character classification is identical to the classification in the Data.Char module.

Functions for identifying and manipulating character codes.

Manipulate ByteStrings using Char operations. All Chars will be truncated to 8 bits. It can be expected that these functions will run at identical speeds to their Word8 equivalents in Data.ByteString. More specifically these byte strings are taken to be in the subset of Unicode covered by code points 0-255. This covers Unicode Basic Latin, Latin-1 Supplement and C0+C1 Controls. See:

• http://www.unicode.org/charts/
• http://www.unicode.org/charts/PDF/U0000.pdf
• http://www.unicode.org/charts/PDF/U0080.pdf

This module is intended to be imported qualified, to avoid name clashes with Prelude functions. eg.

import qualified Data.ByteString.Char8 as C

The Char8 interface to bytestrings provides an instance of IsString for the ByteString type, enabling you to use string literals, and have them implicitly packed to ByteStrings. Use {-# LANGUAGE OverloadedStrings #-} to enable this.