Reserve $ symbol.
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Stephen Chung
parent
44f8d9e429
commit
1de44c7ecd
@ -8,7 +8,7 @@ Literals Syntax
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| `INT` | decimal: `42`, `-123`, `0`<br/>hex: `0x????..`<br/>binary: `0b????..`<br/>octal: `0o????..` |
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| `FLOAT` | `42.0`, `-123.456`, `0.0` |
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| [String] | `"... \x?? \u???? \U???????? ..."` |
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| Character | single: `'?'`<br/>ASCII hex: `'\x??'`<br/>Unicode: `'\u????'`, `'\U????????'` |
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| [Character][string] | single: `'?'`<br/>ASCII hex: `'\x??'`<br/>Unicode: `'\u????'`, `'\U????????'` |
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| [`Array`] | `[ ???, ???, ??? ]` |
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| [Object map] | `#{ a: ???, b: ???, c: ???, "def": ??? }` |
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| Boolean true | `true` |
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@ -7,46 +7,62 @@ Operators and Symbols
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Operators
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---------
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| Operator | Description | Binary? | Binding direction |
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| :---------------: | ------------------------------ | :-----: | :---------------: |
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| `+` | add | yes | left |
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| `-` | subtract, Minus | yes/no | left |
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| `*` | multiply | yes | left |
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| `/` | divide | yes | left |
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| `%` | modulo | yes | left |
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| `~` | power | yes | left |
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| `>>` | right bit-shift | yes | left |
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| `<<` | left bit-shift | yes | left |
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| `&` | bit-wise _And_, boolean _And_ | yes | left |
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| <code>\|</code> | bit-wise _Or_, boolean _Or_ | yes | left |
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| `^` | bit-wise _Xor_, boolean _Xor_ | yes | left |
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| `==` | equals to | yes | left |
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| `~=` | not equals to | yes | left |
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| `>` | greater than | yes | left |
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| `>=` | greater than or equals to | yes | left |
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| `<` | less than | yes | left |
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| `<=` | less than or equals to | yes | left |
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| `&&` | boolean _And_ (short-circuits) | yes | left |
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| <code>\|\|</code> | boolean _Or_ (short-circuits) | yes | left |
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| `!` | boolean _Not_ | no | left |
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| `[` .. `]` | indexing | yes | right |
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| `.` | property access, method call | yes | right |
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| Operator | Description | Binary? | Binding direction |
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| :-----------------------------------------------------------------------------------------: | -------------------------------------- | :--------: | :---------------: |
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| `+` | add | yes | left |
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| `-` | 1) subtract<br/>2) negative | yes<br/>no | left<br/>right |
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| `*` | multiply | yes | left |
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| `/` | divide | yes | left |
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| `%` | modulo | yes | left |
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| `~` | power | yes | left |
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| `>>` | right bit-shift | yes | left |
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| `<<` | left bit-shift | yes | left |
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| `&` | 1) bit-wise _And_<br/>2) boolean _And_ | yes | left |
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| <code>\|</code> | 1) bit-wise _Or_<br/>2) boolean _Or_ | yes | left |
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| `^` | 1) bit-wise _Xor_<br/>2) boolean _Xor_ | yes | left |
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| `=`, `+=`, `-=`, `*=`, `/=`,<br/>`~=`, `%=`, `<<=`, `>>=`, `&=`,<br/><code>\|=</code>, `^=` | assignments | yes | right |
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| `==` | equals to | yes | left |
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| `~=` | not equals to | yes | left |
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| `>` | greater than | yes | left |
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| `>=` | greater than or equals to | yes | left |
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| `<` | less than | yes | left |
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| `<=` | less than or equals to | yes | left |
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| `&&` | boolean _And_ (short-circuits) | yes | left |
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| <code>\|\|</code> | boolean _Or_ (short-circuits) | yes | left |
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| `!` | boolean _Not_ | no | left |
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| `[` .. `]` | indexing | yes | right |
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| `.` | 1) property access<br/>2) method call | yes | right |
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Symbols
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-------
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Symbols and Patterns
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--------------------
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| Symbol | Description |
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| ------------ | ------------------------ |
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| `:` | property value separator |
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| `::` | module path separator |
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| `#` | _reserved_ |
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| `=>` | _reserved_ |
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| `->` | _reserved_ |
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| `<-` | _reserved_ |
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| `===` | _reserved_ |
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| `!==` | _reserved_ |
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| `:=` | _reserved_ |
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| `::<` .. `>` | _reserved_ |
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| `@` | _reserved_ |
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| `(*` .. `*)` | _reserved_ |
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| Symbol | Name | Description |
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| ---------------------------------- | :------------------: | ------------------------------------- |
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| `;` | semicolon | statement separator |
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| `,` | comma | list separator |
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| `:` | colon | [object map] property value separator |
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| `::` | path | module path separator |
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| `#{` .. `}` | hash map | [object map] literal |
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| `"` .. `"` | double quote | [string] |
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| `'` .. `'` | single quote | [character][string] |
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| `\` | escape | escape character literal |
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| `(` .. `)` | parentheses | expression grouping |
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| `{` .. `}` | braces | block statement |
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| <code>\|</code> .. <code>\|</code> | pipes | closure |
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| `[` .. `]` | brackets | [array] literal |
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| `!` | bang | function call in calling scope |
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| `//` | comment | line comment |
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| `/*` .. `*/` | comment | block comment |
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| `(*` .. `*)` | comment | _reserved_ |
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| `<` .. `>` | angular brackets | _reserved_ |
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| `#` | hash | _reserved_ |
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| `@` | at | _reserved_ |
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| `$` | dollar | _reserved_ |
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| `=>` | double arrow | _reserved_ |
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| `->` | arrow | _reserved_ |
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| `<-` | left arrow | _reserved_ |
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| `===` | strict equals to | _reserved_ |
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| `!==` | strict not equals to | _reserved_ |
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| `:=` | assignment | _reserved_ |
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| `::<` .. `>` | turbofish | _reserved_ |
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@ -47,9 +47,13 @@ Constants propagation is used to remove dead code:
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```rust
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const ABC = true;
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if ABC || some_work() { print("done!"); } // 'ABC' is constant so it is replaced by 'true'...
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if true || some_work() { print("done!"); } // since '||' short-circuits, 'some_work' is never called
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if true { print("done!"); } // <- the line above is equivalent to this
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print("done!"); // <- the line above is further simplified to this
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// because the condition is always true
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```
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@ -84,13 +88,15 @@ Rhai guarantees that no external function will be run (in order not to trigger s
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optimization process (unless the optimization level is set to [`OptimizationLevel::Full`]).
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```rust
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const DECISION = 1; // this is an integer, one of the standard types
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// The following is most likely generated by machine.
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if DECISION == 1 { // this is optimized into 'true'
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const DECISION = 1; // this is an integer, one of the standard types
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if DECISION == 1 { // this is optimized into 'true'
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:
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} else if DECISION == 2 { // this is optimized into 'false'
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} else if DECISION == 2 { // this is optimized into 'false'
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:
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} else if DECISION == 3 { // this is optimized into 'false'
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} else if DECISION == 3 { // this is optimized into 'false'
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:
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} else {
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:
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@ -101,9 +107,9 @@ Because of the eager evaluation of operators for [standard types], many constant
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and replaced by the result.
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```rust
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let x = (1+2)*3-4/5%6; // will be replaced by 'let x = 9'
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let x = (1+2) * 3-4 / 5%6; // will be replaced by 'let x = 9'
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let y = (1>2) || (3<=4); // will be replaced by 'let y = true'
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let y = (1 > 2) || (3 < =4); // will be replaced by 'let y = true'
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```
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For operators that are not optimized away due to one of the above reasons, the function calls
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@ -116,12 +122,12 @@ const DECISION_1 = new_state(1);
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const DECISION_2 = new_state(2);
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const DECISION_3 = new_state(3);
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if DECISION == 1 { // NOT optimized away because the operator is not built-in
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: // and may cause side-effects if called!
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if DECISION == 1 { // NOT optimized away because the operator is not built-in
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: // and may cause side-effects if called!
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:
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} else if DECISION == 2 { // same here, NOT optimized away
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} else if DECISION == 2 { // same here, NOT optimized away
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:
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} else if DECISION == 3 { // same here, NOT optimized away
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} else if DECISION == 3 { // same here, NOT optimized away
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:
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} else {
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:
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@ -26,8 +26,8 @@ more control over what a script can (or cannot) do.
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| `no_closure` | no | disables [capturing][automatic currying] external variables in [anonymous functions] to simulate _closures_, or [capturing the calling scope]({{rootUrl}}/language/fn-capture.md) in function calls |
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| `no_std` | no | builds for `no-std` (implies `no_closure`). Notice that additional dependencies will be pulled in to replace `std` features |
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| `serde` | yes | enables serialization/deserialization via `serde`. Notice that the [`serde`](https://crates.io/crates/serde) crate will be pulled in together with its dependencies |
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| `internals` | yes | exposes internal data structures (e.g. [`AST`] nodes). Beware that Rhai internals are volatile and may change from version to version |
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| `unicode-xid-ident` | no | allows [Unicode Standard Annex #31](http://www.unicode.org/reports/tr31/) as identifiers |
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| `internals` | yes | exposes internal data structures (e.g. [`AST`] nodes). Beware that Rhai internals are volatile and may change from version to version |
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Example
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@ -1391,6 +1391,8 @@ fn get_next_token_inner(
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('@', _) => return Some((Token::Reserved("@".into()), start_pos)),
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('$', _) => return Some((Token::Reserved("$".into()), start_pos)),
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('\0', _) => unreachable!(),
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(ch, _) if ch.is_whitespace() => (),
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