ASFv2.0.8

Summary

ASF v2.0.8 introduces modern JavaScript-style spread/rest operators (...) and array destructuring assignments, significantly enhancing array manipulation capabilities and function parameter handling.

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Highlights

• Added

  • Spread/rest operator (...) support:

            // Spread in array literals
            arr1 = [1, 2, 3];
            arr2 = [0, ...arr1, 4, 5]; // => [0, 1, 2, 3, 4, 5]
            
            // Spread in function calls
            fun add(a, b, c) { return a + b + c; };
            numbers = [1, 2, 3];
            result = add(...numbers); // => 6
            
            // Rest parameters in functions
            fun sum(first, ...rest) {
                total = first;
                rest.forEach(fun(n) { total = total + n });
                return total;
            };
            sum(1, 2, 3, 4, 5); // => 15
            
            // Spread strings into character arrays
            chars = [...'hello']; // => ['h', 'e', 'l', 'l', 'o']

  • Array destructuring assignments:

            // Basic destructuring
            [a, b, c] = [1, 2, 3]; // a=1, b=2, c=3
            
            // With rest element
            [first, ...rest] = [1, 2, 3, 4, 5];
            // first=1, rest=[2, 3, 4, 5]
            
            // Fewer targets than elements
            [x, y] = [10, 20, 30, 40]; // x=10, y=20
            
            // More targets than elements (assigns Empty)
            [p, q, r] = [100, 200]; // p=100, q=200, r=Empty
            
            // Practical use cases
            [a, b] = [b, a]; // Swap variables
            [head, ...tail] = myArray; // Extract head and tail
            
            // Combine spread and destructuring
            arr1 = [1, 2];
            arr2 = [3, 4];
            [first, ...combined] = [...arr1, ...arr2];
            // first=1, combined=[2, 3, 4]

• Internal core changes:

  • Parser (ASF_Parser.cls):

    • Added tokenization for ... spread/rest operator
    • New token type: "SPREAD" with value "..."

  • Compiler (ASF_Compiler.cls):

    • Added IsSpreadToken() helper function for spread operator detection
    • Rest parameter support in function and method definitions
    • Spread operator handling in array literal compilation (ParseArrayLiteral)
    • Spread operator support in function call argument processing
    • Array destructuring pattern detection in ParseStatementTokensToAST
    • New AST node type: "ArrayDestructuring" with targets collection and optional rest target
    • Compile-time validation:
      • Rest parameter must be last in function signatures
      • Only one rest parameter allowed per function
      • Rest element must be last in destructuring patterns
      • Multiple rest elements not allowed in destructuring patterns

  • VM (ASF_VM.cls):

    • Spread operator evaluation in EvalArrayNode with type handling
    • Array expansion for arrays, strings, and scalar values
    • Spread operator support in function call argument expansion
    • Rest parameter handling in function calls with automatic array creation
    • New "ArrayDestructuring" case handler in ExecuteStmtNode

• Technical Details:

  • Spread/Rest Token Structure:

            Token: ["SPREAD", "..."]
    

  • Rest Parameter AST:

            Function/Method node {
              params: Collection of parameter names
              restParam: String (optional)
              ...
            }
    

  • Array Destructuring AST:

            ArrayDestructuring {
              targets: Collection of Variable nodes
              restTarget: String (optional)
              source: Expression node
            }
    

  • Error Messages:

    • "Rest parameter must be last parameter" - Rest parameter not in final position
    • "Multiple rest parameters not allowed" - More than one rest parameter in function
    • "Rest element must be last in destructuring" - Rest element not in final position
    • "Multiple rest elements in destructuring" - More than one rest element in pattern
    • "Expected identifier after ... in destructuring" - Invalid rest syntax
    • "Cannot destructure non-array value" - Runtime type validation failure

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Full Changelog: v2.0.7...v2.0.8