Oak Pascal Parser

High-performance incremental Pascal parser for the oak ecosystem with flexible configuration, optimized for legacy code analysis and educational purposes.

🎯 Overview

Oak Pascal is a robust parser for Pascal, designed to handle complete Pascal syntax including legacy and modern features. Built on the solid foundation of oak-core, it provides both high-level convenience and detailed AST generation for code analysis and educational purposes.

✨ Features

• Complete Pascal Syntax: Supports all Pascal features including legacy specifications
• Full AST Generation: Generates comprehensive Abstract Syntax Trees
• Lexer Support: Built-in tokenization with proper span information
• Error Recovery: Graceful handling of syntax errors with detailed diagnostics

🚀 Quick Start

Basic example:

use oak_pascal::{Parser, PascalLanguage, SourceText};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let parser = Parser::new();
    let source = SourceText::new(r#"
program HelloWorld;
begin
    writeln('Hello, World!');
end.
    "#);
    
    let result = parser.parse(&source);
    println!("Parsed Pascal successfully.");
    Ok(())
}

📋 Parsing Examples

Program Parsing

use oak_pascal::{Parser, PascalLanguage, SourceText};

let parser = Parser::new();
let source = SourceText::new(r#"
program Calculator;
uses
    SysUtils;
var
    x, y: integer;
begin
    x := 10;
    y := 20;
    writeln(x + y);
end.
"#);

let result = parser.parse(&source);
println!("Program parsed successfully.");

Procedure Parsing

use oak_pascal::{Parser, PascalLanguage, SourceText};

let parser = Parser::new();
let source = SourceText::new(r#"
procedure Greet(name: string);
begin
    writeln('Hello, ', name);
end;
"#);

let result = parser.parse(&source);
println!("Procedure parsed successfully.");

🔧 Advanced Features

Token-Level Parsing

use oak_pascal::{Parser, PascalLanguage, SourceText};

let parser = Parser::new();
let source = SourceText::new("program Test; begin end.");
let result = parser.parse(&source);
println!("Token parsing completed.");

Error Handling

use oak_pascal::{Parser, PascalLanguage, SourceText};

let parser = Parser::new();
let source = SourceText::new(r#"
program Test
begin
    writeln('Missing semicolon')
end.
"#);

let result = parser.parse(&source);
if let Some(errors) = result.result.err() {
    println!("Parse errors found: {:?}", errors);
} else {
    println!("Parsed successfully.");
}

🏗️ AST Structure

The parser generates a comprehensive AST with the following main structures:

• PascalProgram: Root container for Pascal programs
• Procedure: Procedure declarations
• Function: Function declarations
• Variable: Variable declarations with types
• Statement: Various statement types (assignment, if, while, for, etc.)
• Expression: Arithmetic, logical, and relational expressions

📊 Performance

• Streaming: Parse large Pascal files without loading entirely into memory
• Incremental: Re-parse only changed sections
• Memory Efficient: Smart AST node allocation
• Fast Recovery: Quick error recovery for better IDE integration

🔗 Integration

Oak Pascal integrates seamlessly with:

• Legacy Code Analysis: Analyze and understand legacy Pascal codebases
• Educational Tools: Build programming language learning platforms
• IDE Support: Language server protocol compatibility
• Documentation Tools: Extract documentation from Pascal source code
• Migration Tools: Convert Pascal code to other languages

📚 Examples

Check out the examples directory for comprehensive examples:

• Complete Pascal program parsing
• Procedure and function analysis
• Variable and type extraction
• Integration with development workflows

🤝 Contributing

Contributions are welcome!

Please feel free to submit pull requests at the project repository or open issues.