hetu_script 0.1.0+1

Hetu is a lightweight script language written in Dart for embedding in Flutter apps.

0.1.0+1

• Feat: String interpolation. Example:

var a = 'dragon'
// print: To kill the dragon, you have to wait 42 years.
print('To kill the ${a}, you have to wait ${6*7} years.')

• Fixed Several bugs.

0.1.0

• Feature: Changed default interpreter to a bytecode evaluater.
• Feature: Now fully support nested function and literal function. Example:

fun closure(func) {
  var i = 42
  fun nested () {
    i = i + 1
    print(func(i))
  }
  return nested
}

fun main {
  var func = closure( fun (n) { return n * n } )
  func() // print: 1849
  func() // print: 1936
}

• Feature: Added ++, -- post and pre operators, and +=, -=, *=, /= operators.
• Feature: Added full support on While, Do loops, and both classic for(init;condition;increment) and for...in/of.
• Feature: Added When statement, works like switch.

Loops and When statement example:

fun main {
  var i = 0
  for (;;) {
    ++i
    when (i % 2) {
      0: print('even:', i)
      1: print('odd:', i)
      else: print('never going to happen.')
    }
    if (i > 5) {
      break
    }
  }
}

The output is:

odd: 1
even: 2
odd: 3
even: 4
odd: 5
even: 6

• Feature: Added Ternary operator: 'conditon ? true : false'.
• Feature: Added new interpreter function for bind Dart Function Typedef. Example:

In Hetu script:

fun [DartFunction] add(a: num, b: num): num {
  return a + b
}

fun getFunc {
  return add
}

Then when you evaluate this [add] function in Hetu, you will get a native Dart function.

typedef DartFunction = int Function(int a, int b);

int hetuAdd(DartFunction func) {
  var func = hetu.invoke('getFunc');
  return func(6, 7);
}

You have to bind the Dart typedef in [Interpreter.init] before you can use it.

await hetu.init(externalFunctions: {
  externalFunctionTypedef: {
  'DartFunction': (HTFunction function) {
    return (int a, int b) {
      // must convert the return type here to let dart know its return value type.
      return function.call([a, b]) as int;
    };
  },
});

• Added empty string check in module handler.

0.0.6

• Feature: Error & import are now handle by plugins.
• Change: [evalf] function of interpreter now changed into [import]
• Change: External static members' id unified into [className.varName] in binding.

0.0.5

• Refactor: Migrate to null safety.
• Refactor: Redesigned the binding (external classes, functions and variables).
• Refactor: Redesigned the error handling.

0.0.4

• Feature: External class.
• Refactor: Build-in dart types.

0.0.3

• Feature: Literal function expression (anonymous function). Usage:

fun main {
  var func = fun (name: str) {
    return name + '_postfix'
  }

  print(func())
}

• Feature: Named function parameters.
• Feature: Support literal hexadecimal numbers.
• Fixed class extends, member override and inheritance.
• Fixed import statement.

0.0.2+4

• Fixed bug in method calling of instances.
• Fixed bug of optional function parameters.
• Fixed bug of import statement.
• Fixed bug of member get from super classes.
• Fixed bug of method expression resolving.

0.0.2+1

• Added multiline comment.
• Fixed bugs in method calling of instances.

0.0.2

• Fixed core library loading issue, no longer use outside source files.
• Changed lisence from GNU GPLv3 to MIT.

0.0.1

• Initial version, hello world!