vercel-labs--zerolang/docs/articles/modules/text.md

When To Use std.text

In Zerolang, use std.text for ASCII and UTF-8 byte-backed validation.

Runnable today:

std.text is for byte-backed text validation and counting. It does not imply locale-aware case mapping, grapheme segmentation, normalization, or display-width rules.

API	Return	Notes
std.text.isAscii(text)	Bool	Checks that every byte is below 0x80.
std.text.utf8Valid(text)	Bool	Validates UTF-8 byte structure, rejecting overlong encodings, surrogate code points, and values above U+10FFFF.
std.text.utf8Len(text)	Maybe<usize>	Counts Unicode scalar values when UTF-8 is valid; returns null on invalid input.

Example

pub fn main(world: World) -> Void raises {
    let valid: [2]u8 = [195_u8, 169_u8]
    let invalid: [1]u8 = [128_u8]
    let len: Maybe<usize> = std.text.utf8Len(valid)
    if !std.text.isAscii(valid) && std.text.utf8Valid(valid) && !std.text.utf8Valid(invalid) && len.has && len.value == 1 {
        check world.out.write("text ok\n")
    }
}

Effects: none.

Allocation behavior: no allocation.

Error behavior: utf8Len returns null for invalid UTF-8.

Target support: current compiler targets.