Custom JavaScript string rust type

boa/src/builtins/console/mod.rs

@@ -20,8 +20,8 @@ use crate::{
     builtins::BuiltIn,
     object::ObjectInitializer,
     property::Attribute,
-    value::{display::display_obj, RcString, Value},
-    BoaProfiler, Context, Result,
+    value::{display::display_obj, Value},
+    BoaProfiler, Context, JsString, Result,
 };
 use rustc_hash::FxHashMap;
 use std::time::SystemTime;
@@ -137,8 +137,8 @@ pub fn formatter(data: &[Value], context: &mut Context) -> Result<String> {
 /// This is the internal console object state.
 #[derive(Debug, Default)]
 pub(crate) struct Console {
-    count_map: FxHashMap<RcString, u32>,
-    timer_map: FxHashMap<RcString, u128>,
+    count_map: FxHashMap<JsString, u32>,
+    timer_map: FxHashMap<JsString, u128>,
     groups: Vec<String>,
 }
 

boa/src/builtins/json/mod.rs

@@ -15,12 +15,13 @@
 
 use crate::{
     builtins::BuiltIn,
+    object::Object,
     object::ObjectInitializer,
     property::{Attribute, DataDescriptor, PropertyKey},
+    symbol::WellKnownSymbols,
     value::IntegerOrInfinity,
     BoaProfiler, Context, Result, Value,
 };
-use crate::{object::Object, symbol::WellKnownSymbols};
 use serde::Serialize;
 use serde_json::{self, ser::PrettyFormatter, Serializer, Value as JSONValue};
 

boa/src/builtins/object/for_in_iterator.rs

@@ -1,12 +1,12 @@
-use crate::value::RcString;
 use crate::{
     builtins::{function::make_builtin_fn, iterable::create_iter_result_object},
     gc::{Finalize, Trace},
     object::{GcObject, ObjectData},
+    property::PropertyKey,
     property::{Attribute, DataDescriptor},
-    BoaProfiler, Context, Result, Value,
+    symbol::WellKnownSymbols,
+    BoaProfiler, Context, JsString, Result, Value,
 };
-use crate::{property::PropertyKey, symbol::WellKnownSymbols};
 use rustc_hash::FxHashSet;
 use std::collections::VecDeque;
 
@@ -20,8 +20,8 @@ use std::collections::VecDeque;
 #[derive(Debug, Clone, Finalize, Trace)]
 pub struct ForInIterator {
     object: Value,
-    visited_keys: FxHashSet<RcString>,
-    remaining_keys: VecDeque<RcString>,
+    visited_keys: FxHashSet<JsString>,
+    remaining_keys: VecDeque<JsString>,
     object_was_visited: bool,
 }
 

boa/src/builtins/regexp/mod.rs

@@ -17,8 +17,8 @@ use crate::{
     object::{ConstructorBuilder, FunctionBuilder, GcObject, ObjectData, PROTOTYPE},
     property::{Attribute, DataDescriptor},
     symbol::WellKnownSymbols,
-    value::{IntegerOrInfinity, RcString, Value},
-    BoaProfiler, Context, Result,
+    value::{IntegerOrInfinity, Value},
+    BoaProfiler, Context, JsString, Result,
 };
 use regexp_string_iterator::RegExpStringIterator;
 use regress::Regex;
@@ -650,7 +650,7 @@ impl RegExp {
     /// [spec]: https://tc39.es/ecma262/#sec-regexpexec
     pub(crate) fn abstract_exec(
         this: &Value,
-        input: RcString,
+        input: JsString,
         context: &mut Context,
     ) -> Result<Value> {
         // 1. Assert: Type(R) is Object.
@@ -694,7 +694,7 @@ impl RegExp {
     /// [spec]: https://tc39.es/ecma262/#sec-regexpbuiltinexec
     pub(crate) fn abstract_builtin_exec(
         this: &Value,
-        input: RcString,
+        input: JsString,
         context: &mut Context,
     ) -> Result<Value> {
         // 1. Assert: R is an initialized RegExp instance.
@@ -1160,7 +1160,7 @@ impl RegExp {
         }
 
         // 12. Let accumulatedResult be the empty String.
-        let mut accumulated_result = RcString::from("");
+        let mut accumulated_result = JsString::new("");
 
         // 13. Let nextSourcePosition be 0.
         let mut next_source_position = 0;
@@ -1227,7 +1227,7 @@ impl RegExp {
 
             // k. If functionalReplace is true, then
             // l. Else,
-            let replacement: RcString;
+            let replacement: JsString;
             if functional_replace {
                 // i. Let replacerArgs be « matched ».
                 let mut replacer_args = vec![Value::from(matched)];
@@ -1553,7 +1553,7 @@ impl RegExp {
 ///  - [ECMAScript reference][spec]
 ///
 /// [spec]: https://tc39.es/ecma262/#sec-advancestringindex
-fn advance_string_index(s: RcString, index: usize, unicode: bool) -> usize {
+fn advance_string_index(s: JsString, index: usize, unicode: bool) -> usize {
     // Regress only works with utf8, so this function differs from the spec.
 
     // 1. Assert: index ≤ 2^53 - 1.

boa/src/builtins/regexp/regexp_string_iterator.rs

@@ -17,23 +17,22 @@ use crate::{
     object::{GcObject, ObjectData},
     property::{Attribute, DataDescriptor},
     symbol::WellKnownSymbols,
-    value::RcString,
-    BoaProfiler, Context, Result, Value,
+    BoaProfiler, Context, JsString, Result, Value,
 };
 
 // TODO: See todos in create_regexp_string_iterator and next.
 #[derive(Debug, Clone, Finalize, Trace)]
 pub struct RegExpStringIterator {
     matcher: Value,
-    string: RcString,
+    string: JsString,
     global: bool,
     unicode: bool,
     completed: bool,
 }
 
 // TODO: See todos in create_regexp_string_iterator and next.
 impl RegExpStringIterator {
-    fn new(matcher: Value, string: RcString, global: bool, unicode: bool) -> Self {
+    fn new(matcher: Value, string: JsString, global: bool, unicode: bool) -> Self {
         Self {
             matcher,
             string,
@@ -51,7 +50,7 @@ impl RegExpStringIterator {
     /// [spec]: https://tc39.es/ecma262/#sec-createregexpstringiterator
     pub(crate) fn create_regexp_string_iterator(
         matcher: &Value,
-        string: RcString,
+        string: JsString,
         global: bool,
         unicode: bool,
         context: &mut Context,

boa/src/builtins/string/mod.rs

@@ -21,8 +21,7 @@ use crate::{
     object::{ConstructorBuilder, Object, ObjectData},
     property::Attribute,
     symbol::WellKnownSymbols,
-    value::{RcString, Value},
-    BoaProfiler, Context, Result,
+    BoaProfiler, Context, JsString, Result, Value,
 };
 use std::{
     char::{decode_utf16, from_u32},
@@ -31,7 +30,7 @@ use std::{
 };
 use unicode_normalization::UnicodeNormalization;
 
-pub(crate) fn code_point_at(string: RcString, position: i32) -> Option<(u32, u8, bool)> {
+pub(crate) fn code_point_at(string: JsString, position: i32) -> Option<(u32, u8, bool)> {
     let size = string.encode_utf16().count() as i32;
     if position < 0 || position >= size {
         return None;
@@ -170,7 +169,7 @@ impl String {
                     .clone()
             }
             Some(ref value) => value.to_string(context)?,
-            None => RcString::default(),
+            None => JsString::default(),
         };
 
         if new_target.is_undefined() {
@@ -202,7 +201,7 @@ impl String {
         Ok(this)
     }
 
-    fn this_string_value(this: &Value, context: &mut Context) -> Result<RcString> {
+    fn this_string_value(this: &Value, context: &mut Context) -> Result<JsString> {
         match this {
             Value::String(ref string) => return Ok(string.clone()),
             Value::Object(ref object) => {
@@ -685,10 +684,9 @@ impl String {
 
         // 11. If functionalReplace is true, then
         // 12. Else,
-        let replacement: RcString;
-        if functional_replace {
+        let replacement = if functional_replace {
             // a. Let replacement be ? ToString(? Call(replaceValue, undefined, « searchString, 𝔽(position), string »)).
-            replacement = context
+            context
                 .call(
                     &replace_value,
                     &Value::Undefined,
@@ -698,22 +696,22 @@ impl String {
                         this_str.clone().into(),
                     ],
                 )?
-                .to_string(context)?;
+                .to_string(context)?
         } else {
             // a. Assert: Type(replaceValue) is String.
             // b. Let captures be a new empty List.
             let captures = Vec::new();
 
             // c. Let replacement be ! GetSubstitution(searchString, string, position, captures, undefined, replaceValue).
-            replacement = get_substitution(
+            get_substitution(
                 search_str.to_string(),
                 this_str.to_string(),
                 position.unwrap(),
                 captures,
                 Value::undefined(),
                 replace_value.to_string(context)?.to_string(),
-            )?;
-        }
+            )?
+        };
 
         // 13. Return the string-concatenation of preserved, replacement, and the substring of string from position + searchLength.
         Ok(format!(
@@ -862,9 +860,9 @@ impl String {
     /// Performs the actual string padding for padStart/End.
     /// <https://tc39.es/ecma262/#sec-stringpad/>
     fn string_pad(
-        primitive: RcString,
+        primitive: JsString,
         max_length: i32,
-        fill_string: Option<RcString>,
+        fill_string: Option<JsString>,
         at_start: bool,
     ) -> Value {
         let primitive_length = primitive.len() as i32;
@@ -1480,7 +1478,7 @@ pub(crate) fn get_substitution(
     captures: Vec<Value>,
     _named_captures: Value,
     replacement: StdString,
-) -> Result<RcString> {
+) -> Result<JsString> {
     // 1. Assert: Type(matched) is String.
 
     // 2. Let matchLength be the number of code units in matched.

boa/src/bytecompiler.rs

@@ -4,9 +4,9 @@ use crate::{
         op::{AssignOp, BinOp, BitOp, CompOp, LogOp, NumOp, UnaryOp},
         Const, Node,
     },
-    value::{RcBigInt, RcString},
+    value::RcBigInt,
     vm::{CodeBlock, Opcode},
-    Value,
+    JsString, Value,
 };
 
 use std::collections::HashMap;
@@ -34,7 +34,7 @@ fn u64_to_array(value: u64) -> [u8; 8] {
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 enum Literal {
-    String(RcString),
+    String(JsString),
     BigInt(RcBigInt),
 }
 
@@ -64,7 +64,7 @@ enum Access<'a> {
 pub struct ByteCompiler {
     code_block: CodeBlock,
     literals_map: HashMap<Literal, u32>,
-    names_map: HashMap<RcString, u32>,
+    names_map: HashMap<JsString, u32>,
     loops: Vec<LoopControlInfo>,
 }
 
@@ -111,7 +111,7 @@ impl ByteCompiler {
             return *index;
         }
 
-        let name: RcString = name.into();
+        let name = JsString::new(name);
         let index = self.code_block.names.len() as u32;
         self.code_block.names.push(name.clone());
         self.names_map.insert(name, index);

boa/src/lib.rs

@@ -54,6 +54,7 @@ pub mod object;
 pub mod profiler;
 pub mod property;
 pub mod realm;
+pub mod string;
 pub mod symbol;
 // syntax module has a lot of acronyms
 #[allow(clippy::upper_case_acronyms)]
@@ -71,7 +72,7 @@ pub(crate) use crate::{exec::Executable, profiler::BoaProfiler};
 
 // Export things to root level
 #[doc(inline)]
-pub use crate::{context::Context, symbol::JsSymbol, value::Value};
+pub use crate::{context::Context, string::JsString, symbol::JsSymbol, value::Value};
 
 use crate::syntax::{
     ast::node::StatementList,

boa/src/object/iter.rs

@@ -1,5 +1,5 @@
 use super::{Object, PropertyDescriptor, PropertyKey};
-use crate::{value::RcString, JsSymbol};
+use crate::{JsString, JsSymbol};
 use std::{collections::hash_map, iter::FusedIterator};
 
 impl Object {
@@ -109,7 +109,7 @@ impl Object {
 #[derive(Debug, Clone)]
 pub struct Iter<'a> {
     indexed_properties: hash_map::Iter<'a, u32, PropertyDescriptor>,
-    string_properties: hash_map::Iter<'a, RcString, PropertyDescriptor>,
+    string_properties: hash_map::Iter<'a, JsString, PropertyDescriptor>,
     symbol_properties: hash_map::Iter<'a, JsSymbol, PropertyDescriptor>,
 }
 
@@ -342,10 +342,10 @@ impl FusedIterator for IndexPropertyValues<'_> {}
 
 /// An iterator over the `String` property entries of an `Object`
 #[derive(Debug, Clone)]
-pub struct StringProperties<'a>(hash_map::Iter<'a, RcString, PropertyDescriptor>);
+pub struct StringProperties<'a>(hash_map::Iter<'a, JsString, PropertyDescriptor>);
 
 impl<'a> Iterator for StringProperties<'a> {
-    type Item = (&'a RcString, &'a PropertyDescriptor);
+    type Item = (&'a JsString, &'a PropertyDescriptor);
 
     #[inline]
     fn next(&mut self) -> Option<Self::Item> {
@@ -369,10 +369,10 @@ impl FusedIterator for StringProperties<'_> {}
 
 /// An iterator over the string keys (`RcString`) of an `Object`.
 #[derive(Debug, Clone)]
-pub struct StringPropertyKeys<'a>(hash_map::Keys<'a, RcString, PropertyDescriptor>);
+pub struct StringPropertyKeys<'a>(hash_map::Keys<'a, JsString, PropertyDescriptor>);
 
 impl<'a> Iterator for StringPropertyKeys<'a> {
-    type Item = &'a RcString;
+    type Item = &'a JsString;
 
     #[inline]
     fn next(&mut self) -> Option<Self::Item> {
@@ -396,7 +396,7 @@ impl FusedIterator for StringPropertyKeys<'_> {}
 
 /// An iterator over the string values (`Property`) of an `Object`.
 #[derive(Debug, Clone)]
-pub struct StringPropertyValues<'a>(hash_map::Values<'a, RcString, PropertyDescriptor>);
+pub struct StringPropertyValues<'a>(hash_map::Values<'a, JsString, PropertyDescriptor>);
 
 impl<'a> Iterator for StringPropertyValues<'a> {
     type Item = &'a PropertyDescriptor;