Characters

char represents one Unicode scalar value. Its validity, range, and representation match Rust's char type.

A Unicode scalar value is any Unicode code point from U+0000 through U+10FFFF, excluding the surrogate range U+D800 through U+DFFF.

letter is char = 'A'
accented is char = 'é'
emoji is char = '😀'

Typical has one character type. It does not provide separate char8, char16, or char32 primitives. A char is stored in 32 bits regardless of the number of bytes required to encode it as UTF-8.

Scalars And Displayed Characters

A char is one Unicode scalar value, not necessarily one user-perceived character. A displayed character may contain multiple scalars, such as a base letter followed by a combining mark.

'é'	// One scalar: U+00E9
'é'	// ❌ Wrong: two scalars in one character literal

Character literals contain exactly one scalar value. The editor reports a notice when a character literal contains no scalar values or more than one scalar value.

Strings

Ordinary string values contain valid Unicode scalar sequences. Encoding an ordinary string as UTF-8 uses between one and four bytes for each char, even though the char value itself always occupies 32 bits.

Ordinary-string indexing and iteration produce char values. Encoding, byte-string indexing, grapheme segmentation, string slicing, and out-of-range behavior are defined separately in 06-Strings.

Integer Conversion

Converting a char to u32 returns its Unicode scalar value and is lossless.

codePoint is u32 = 'A' // 65

Conversions to narrower integers use the ordinary numeric conversion rules and receive a saw when they may lose information.

Integer conversion exposes a character's scalar value. It does not encode the character as UTF-8, UTF-16, or another character encoding. Encoding is performed through the corresponding encoding APIs.

Numeric Groups

char belongs to AnyNumeric and AnyInteger. This permits character-aware constraints and ranges without defining a separate AnyChar group.

Group membership does not give char arithmetic operators. Convert a character to an integer before performing numeric arithmetic.

'A' + 1 // ❌ Wrong: char does not support arithmetic

codePoint is u32 = 'A'
nextCodePoint = codePoint + 1