Compiler

The Compiler (CSharpToJs)

The compiler is the core component that enables the magic of eQuantic.UI. It transforms C# semantics into efficient and readable TypeScript code.

🛠️ Compiler Components

1. TypeScriptEmitter

The TypeScriptEmitter is the entry point for generating .ts files. It organizes imports, defines classes, and uses the CSharpToJsConverter to convert method bodies.

2. CSharpToJsConverter

A implementation based on the Strategy pattern that traverses the Roslyn syntax tree (AST).

• Each type of C# expression or statement has a dedicated strategy (e.g., BinaryExpressionStrategy, IfStatementStrategy).

3. SourceMapGenerator

Generates standard V3 Source Maps with Base64 VLQ encoding, mapping generated JavaScript/TypeScript back to the original .cs or .eqx source lines.

4. Identifier Heuristics

The converter applies intelligent heuristics to decide how to map variable names:

• C# properties and fields are mapped to this.propertyName in JS.
• Local variables and parameters retain their original names.
• System methods like Console.WriteLine are automatically mapped to console.log.

🔄 Supported Strategies

Currently, the compiler supports a wide range of C# constructs:

• Expressions: Arithmetic, Logical, Ternary, String Interpolation, Null-coalescing (??), Conditional Access (?., ?[]).
• Control Flow: if, switch, for, foreach, while, do-while, break, continue, throw.
• Modern Patterns: Full support for Recursive, Property, Positional, Relational, and Logical patterns (C# 9.0 - 12.0).
• Resource Management: Support for using statements and using var declarations.
• Exceptions: Full support for try-catch-finally and throw statements (Exception → Error).
• Indexes and Ranges: Support for index-from-end operator (array[^1] → array[array.length - 1]).
• LINQ: Direct conversion of LINQ methods to JS equivalents:
  • Projection: Select → map, SelectMany → flatMap
  • Filtering: Where → filter, Distinct → [...new Set()]
  • Ordering: OrderBy/OrderByDescending → sort, Reverse → [...arr].reverse()
  • Partitioning: Skip → slice(n), Take → slice(0, n)
  • Element: First/FirstOrDefault → find/[0], Last/LastOrDefault → arr[arr.length-1], Single/SingleOrDefault → find/[0]
  • Quantifiers: Any → some/length > 0, All → every, Contains → includes
  • Aggregation: Count → length/filter().length, Sum → reduce((a,b) => a+b, 0), Average → reduce()/length, Min → Math.min(...), Max → Math.max(...)
• Async/Await: Mapping of Task to Promise and native await support.

📝 Conversion Example

C# Source:

private void Increment() {
    Count++;
    if (Count > 10) Console.WriteLine("Max reached");
}

TypeScript Output:

increment() {
    this.count++;
    if (this.count > 10) console.log("Max reached");
}