Newest Features to be introduced in Echo!

MufiZ v0.10.0 is packing some new exciting features already, firstly we are adding support for foreach loops!!!

var a = {1, 2, 3};
foreach(x in a){
    print a;
}
// 1
// 2
// 3

The foreach loop was something I wanted to bring in Kova but didn’t get the chance to, and between me switching back and forth between foreach(x in foo) and each(x : foo), I decided to go with well what I already showed, and I’m happy its now in the language!

Next is more helpful error messages! Our error messaging system was all over the place, and now I have gotten it under control, and better under an Error Manager to handle detecting the type of error, and providing suggestions that may help, these suggestions are quite generic but better than nothing ;)

Error Categories

The error system categorizes errors into the following types:

Syntax Errors

• UNEXPECTED_TOKEN: Wrong token found where another was expected

• UNTERMINATED_STRING: String literal missing closing quote

• INVALID_CHARACTER: Invalid or unexpected character in source code

• MISSING_SEMICOLON: Missing semicolon where required

• MISMATCHED_BRACKETS: Mismatched [], {}, or () brackets

Semantic Errors

• UNDEFINED_VARIABLE: Reference to undeclared variable

• REDEFINED_VARIABLE: Variable declared multiple times in same scope

• UNDEFINED_FUNCTION: Call to undefined function

• UNDEFINED_PROPERTY: Access to undefined object property

• WRONG_ARGUMENT_COUNT: Function called with wrong number of arguments

Type Errors

• TYPE_MISMATCH: Operation between incompatible types

• INVALID_CAST: Invalid type conversion

• INCOMPATIBLE_TYPES: Types cannot be used together

Runtime Errors

• STACK_OVERFLOW: Too many nested function calls

• INDEX_OUT_OF_BOUNDS: Array/vector access outside valid range

• NULL_REFERENCE: Access to null object

• DIVISION_BY_ZERO: Division or modulo by zero

Memory/Limit Errors

• TOO_MANY_CONSTANTS: More than 256 constants in one function

• TOO_MANY_LOCALS: More than 256 local variables in function

• TOO_MANY_ARGUMENTS: More than 255 function arguments

• LOOP_TOO_LARGE: Loop body exceeds maximum size (65535 bytes)

• JUMP_TOO_LARGE: Conditional jump distance too large

Class/Object Errors

• INVALID_SUPER_USAGE: 'super' used outside class or without inheritance

• INVALID_SELF_USAGE: 'self' used outside class context

• CLASS_INHERITANCE_ERROR: Invalid class inheritance (e.g., self-inheritance)

• METHOD_NOT_FOUND: Called method doesn't exist on object

Error Message Format

Each error message includes:

1. Severity Level: Error, Warning, Info, or Hint

2. Location: File, line, and column number

3. Category: The type of error (Syntax, Runtime, etc.)

4. Message: Clear description of what went wrong

5. Context: Relevant source code with error highlighting

6. Suggestions: Helpful advice on how to fix the error

7. Examples: Code examples showing correct usage (when applicable)

Example Error Output

Error [script:15:23] (Syntax) Unexpected token 'var', expected ')'
    var result = add(5, var x = 10);
                       ^^^
  Suggestion: Replace 'var' with a valid expression
    Fix: Remove variable declaration from function call
    Example: var result = add(5, x);

  Suggestion: Declare variables outside function calls
    Example: var x = 10; var result = add(5, x);

Common Error Scenarios and Suggestions

Undefined Variables

Error: Undefined variable 'userName'

Suggestions:

• Declare the variable before using it

• Check spelling (did you mean 'username'?)

• Ensure variable is in correct scope

Fix Examples:

// Before (error)
print(userName);

// After (fixed)
var userName = "John";
print(userName);

Wrong Argument Count

Error: Function 'add' expects 2 arguments, but 1 were provided

Suggestions:

• Add the missing argument

• Check function signature

• Verify you're calling the correct function

Fix Examples:

// Before (error)
var result = add(5);

// After (fixed)
var result = add(5, 3);

Stack Overflow

Error: Stack overflow - too many function calls

Suggestions:

• Check for infinite recursion

• Add base case to recursive functions

• Consider using iteration instead

• Limit recursion depth

Fix Examples:

// Before (infinite recursion)
fun factorial(n) {
    return n * factorial(n - 1);
}

// After (with base case)
fun factorial(n) {
    if (n <= 1) return 1;
    return n * factorial(n - 1);
}

Index Out of Bounds

Error: Index 5 is out of bounds for size 3

Suggestions:

• Valid indices are 0 to 2

• Check array/vector size before accessing

• Use bounds checking

Fix Examples:

// Before (unsafe)
var value = arr[index];

// After (safe)
if (index >= 0 && index < arr.length) {
    var value = arr[index];
} else {
    print("Index out of bounds");
}

Invalid Super Usage

Error: Cannot use 'super' outside of a class

Suggestions:

• Use 'super' only inside class methods

• Ensure class has a parent class

• Move super call into class definition

Fix Examples:

// Before (error)
super.method();

// After (fixed)
class Child extends Parent {
    method() {
        super.method();
    }
}

Did You Mean Suggestions

The error system includes intelligent "did you mean" suggestions for:

• Variable names: Suggests similar variable names based on edit distance

• Function names: Suggests similar function names when available

• Method names: Suggests available methods on objects

• Keywords: Suggests correct keywords for typos

Example

Error: Undefined variable 'usrName'
  Suggestion: Did you mean 'userName'?

Error Recovery

The compiler includes panic mode recovery:

1. Enter Panic Mode: When an error is detected

2. Skip Tokens: Continue parsing by skipping problematic tokens

3. Synchronization Points: Recover at statement boundaries

4. Exit Panic Mode: Resume normal parsing

This allows the compiler to report multiple errors in a single compilation pass