git.delta.rocks / jrsonnet / refs/commits / 2b4e36fe5944

259	buf259	buf
260}260}
261
262// Json string encoding was borrowed from https://github.com/serde-rs/json
263
264const BB: u8 = b'b'; // \x08
265const TT: u8 = b't'; // \x09
266const NN: u8 = b'n'; // \x0A
267const FF: u8 = b'f'; // \x0C
268const RR: u8 = b'r'; // \x0D
269const QU: u8 = b'"'; // \x22
270const BS: u8 = b'\\'; // \x5C
271const UU: u8 = b'u'; // \x00...\x1F except the ones above
272const __: u8 = 0;
273
274// Lookup table of escape sequences. A value of b'x' at index i means that byte
275// i is escaped as "\x" in JSON. A value of 0 means that byte i is not escaped.
276static ESCAPE: [u8; 256] = [
277	//   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F
278	UU, UU, UU, UU, UU, UU, UU, UU, BB, TT, NN, UU, FF, RR, UU, UU, // 0
279	UU, UU, UU, UU, UU, UU, UU, UU, UU, UU, UU, UU, UU, UU, UU, UU, // 1
280	__, __, QU, __, __, __, __, __, __, __, __, __, __, __, __, __, // 2
281	__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, // 3
282	__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, // 4
283	__, __, __, __, __, __, __, __, __, __, __, __, BS, __, __, __, // 5
284	__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, // 6
285	__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, // 7
286	__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, // 8
287	__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, // 9
288	__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, // A
289	__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, // B
290	__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, // C
291	__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, // D
292	__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, // E
293	__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, // F
294];
261295
262fn escape_string_json_buf(s: &str, buf: &mut String) {296fn escape_string_json_buf(value: &str, buf: &mut String) {
297	// Safety: we only write correct utf-8 in this function
263	buf.push('"');298	let mut buf: &mut Vec<u8> = unsafe { core::mem::transmute(buf) };
264	for c in s.chars() {299	let bytes = value.as_bytes();
265		match c {300
266			'"' => buf.push_str("\\\""),301	// Perfect for ascii strings, removes any reallocations
302	buf.reserve(value.len() + 2);
303
267			'\\' => buf.push_str("\\\\"),304	buf.push(b'"');
305
306	let mut start = 0;
307
268			'\u{0008}' => buf.push_str("\\b"),308	for (i, &byte) in bytes.iter().enumerate() {
269			'\u{000c}' => buf.push_str("\\f"),309		let escape = ESCAPE[byte as usize];
310		if escape == __ {
311			continue;
312		}
313
314		if start < i {
270			'\n' => buf.push_str("\\n"),315			buf.extend_from_slice(&bytes[start..i]);
271			'\r' => buf.push_str("\\r"),316		}
317		start = i + 1;
318
319		match escape {
272			'\t' => buf.push_str("\\t"),320			self::BB | self::TT | self::NN | self::FF | self::RR | self::QU | self::BS => {
321				buf.extend_from_slice(&[b'\\', escape])
322			}
323			self::UU => {
324				static HEX_DIGITS: [u8; 16] = *b"0123456789abcdef";
325				let bytes = &[
326					b'\\',
327					b'u',
328					b'0',
329					b'0',
273			c if c < 32 as char || (c >= 127 as char && c <= 159 as char) => {330					HEX_DIGITS[(byte >> 4) as usize],
331					HEX_DIGITS[(byte & 0xF) as usize],
332				];
274				write!(buf, "\\u{:04x}", c as u32).unwrap();333				buf.extend_from_slice(bytes)
275			}334			}
276			c => buf.push(c),335			_ => unreachable!(),
277		}336		}
278	}337	}
338
339	if start == bytes.len() {
340		buf.push(b'"');
341		return;
342	}
343
344	buf.extend_from_slice(&bytes[start..]);
279	buf.push('"');345	buf.push(b'"');
280}346}
281347
282pub struct YamlFormat<'s> {348pub struct YamlFormat<'s> {