Changes to deps/swc/crates/swc_ecma_codegen/src/template.rs. All files

deps/swc/crates/swc_ecma_codegen/src/template.rs

new file mode 100644@@ -0,0 +1,64 @@+use std::{iter::Peekable, str::Chars};++/// Decode exactly two hexadecimal digits without consuming the next escape.+pub(crate) fn decode_hex_escape(iter: &mut Peekable<Chars<'_>>) -> Option<char> {+    let mut remaining = iter.clone();+    let high = remaining.next()?.to_digit(16)?;+    let low = remaining.next()?.to_digit(16)?;+    let c = char::from_u32(high * 16 + low)?;+    *iter = remaining;+    Some(c)+}++/// Decode a Unicode escape after its `u`, committing the iterator only when the+/// result can be emitted as a character. Lone surrogates must stay escaped.+pub(crate) fn decode_unicode_escape(+    iter: &mut Peekable<Chars<'_>>,+    ascii_only: bool,+) -> Option<char> {+    let mut remaining = iter.clone();+    let mut value = read_unicode_escape(&mut remaining)?;++    if (0xd800..=0xdbff).contains(&value) {+        if remaining.next()? != '\\' || remaining.next()? != 'u' {+            return None;+        }+        let low = read_unicode_escape(&mut remaining)?;+        if !(0xdc00..=0xdfff).contains(&low) {+            return None;+        }+        value = 0x10000 + ((value - 0xd800) << 10) + low - 0xdc00;+    }++    let c = char::from_u32(value)?;+    if ascii_only && !c.is_ascii() {+        // Keep the original escape instead of expanding it to a braced escape.+        return None;+    }++    *iter = remaining;+    Some(c)+}++fn read_unicode_escape(iter: &mut Peekable<Chars<'_>>) -> Option<u32> {+    let mut value = 0u32;+    if iter.next_if_eq(&'{').is_some() {+        // Read at least one digit; leading zeroes are allowed in braced escapes.+        value = iter.next()?.to_digit(16)?;+        loop {+            let c = iter.next()?;+            if c == '}' {+                return Some(value);+            }+            value = value.checked_mul(16)?.checked_add(c.to_digit(16)?)?;+            if value > 0x10ffff {+                return None;+            }+        }+    }++    for _ in 0..4 {+        value = value * 16 + iter.next()?.to_digit(16)?;+    }+    Some(value)+}