Struct JSStrBuilder 

pub struct JSStrBuilder<'a> { /* private fields */ }

Build a JSStr in an arena, preserving lone surrogates.

Appends concatenated UTF-16 values. A leading surrogate at the end of one append pairs with a trailing surrogate at the start of the next, including across empty appends. into_js_str returns canonical WTF-8 without copying the completed buffer.

use oxc_str::JSStrBuilder;

let mut builder = JSStrBuilder::new_in(&&allocator);
builder.push_code_unit(0xD800);
builder.push_str("");
builder.push_code_unit(0xDC00);
let s = builder.into_js_str();

assert_eq!(s.as_str(), Some("𐀀"));

Implementations

impl<'a> JSStrBuilder<'a>

pub fn new_in(allocator: &impl GetAllocator<'a>) -> Self

Create an empty JSStrBuilder without allocating.

pub fn with_capacity_in( capacity: usize, allocator: &impl GetAllocator<'a>, ) -> Self

Create an empty JSStrBuilder with reserved capacity.

If capacity is 0, does not allocate.

Panics

Panics if capacity exceeds u32::MAX or isize::MAX.

pub fn push_str(&mut self, value: &str)

Append a &str.

pub fn push(&mut self, value: char)

Append a Unicode scalar value.

pub fn push_js_char(&mut self, value: JSChar)

Append one JavaScript code point, pairing surrogates at the boundary.

pub fn push_code_unit(&mut self, unit: u16)

Append one UTF-16 code unit.

Use this for input from a UTF-16 API. Use push_js_char for an already decoded JavaScript code point.

pub fn push_utf16(&mut self, units: &[u16])

Append potentially ill-formed UTF-16.

This accepts code-unit buffers from UTF-16 APIs without replacing lone surrogates. A pair may span consecutive calls, including empty buffers.

pub fn push_code_units(&mut self, units: impl IntoIterator<Item = u16>)

Append potentially ill-formed UTF-16 code units from an iterator, like push_utf16.

pub fn push_js_str(&mut self, value: JSStr<'_>)

Append a JavaScript string, repairing a surrogate pair at the boundary.

UTF-8 inputs are copied without scanning. For inputs with lone surrogates, only the boundary encodings change; the interior is copied as bytes.

pub fn into_js_str(self) -> JSStr<'a>

Consume the builder and return a string without copying or rescanning the buffer.