78 lines
1.5 KiB
Markdown
78 lines
1.5 KiB
Markdown
---
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Title: YREA SLS | 2 Lexical Structure
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Prev: Overview
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Next: Primitive Types
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---
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## 2. Lexical Structure
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### 2.1 Comments
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```
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// Single-line comment
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```
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### 2.2 Identifiers
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**Regular Identifiers**
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- Start with letter or underscore: `[a-zA-Z_][a-zA-Z0-9_]*`
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- Case-sensitive
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- When encountered, identifiers are executed immediately
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**Identifier Literals**
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- Prefix with `::` to push the identifier itself onto the stack instead of executing it
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- Syntax: `::name` pushes the identifier `name` as a value
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- Example: `::Addable` pushes the identifier `Addable` onto the stack
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- Example: `::Point` pushes the identifier `Point` onto the stack
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> **Advanced Usage**: See Section 11.2 for complete identifier literal rules and context-dependent behavior.
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### 2.3 Literals
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**Integer Literals**
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```
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42 // i64 (default)
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42:i32 // Annotate as i32
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0xFF // hexadecimal
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0b1010 // binary
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```
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**Floating Point Literals**
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```
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3.14 // f64 (default)
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3.14:f32 // Annotate as f32
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```
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**String Literals**
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```
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"hello world"
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"escape sequences: \n \t \\ \""
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```
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**Escape Sequences**
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- `\n` - Newline (LF)
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- `\r` - Carriage return (CR)
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- `\t` - Tab
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- `\\` - Backslash
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- `\"` - Double quote
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- `\'` - Single quote
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- `\0` - Null character
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- `\xNN` - Hexadecimal byte (e.g., `\x41` for 'A')
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- `\u{NNNN}` - Unicode code point (e.g., `\u{1F600}` for 😀)
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**Boolean Literals**
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```
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true
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false
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```
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**Array Literals**
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```
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[1 2 3 4 5] // array of i32
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[1.0 2.0 3.0] // array of f64
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[[1 2] [3 4]] // 2D array
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```
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---
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