root/cobra/trunk/HowTo/101-WriteBasicSyntax.cobra

"""
This is a doc string for the whole module.
"""


class Person
    """
    This is a class declaration.
    """

    var _name as String  # declare an object variable. every instance of Person will have a name
    var _age as int

    cue init(name as String, age as int)
        base.init
        _name = name
        _age = age

    def sayHello
        # This is a method

        # In strings, anything in brackets ([]) is evaluated as an expression,
        # converted to a string and substituted into the string:
        print 'Hello. My name is [_name] and I am [_age].'

    def add(i as int, j as int) as int
        """ Adds the two arguments and returns their sum. """
        return i + j


class Program

    def main
        # Create an instance
        p = Person('Bob', 30)

        # Invoke a method
        p.sayHello

        # Invoke a method with arguments
        print p.add(2, 2)

        # Assert the truth of something
        assert p.add(2, 2)==4

        # If statement
        a = 2
        b = 1
        if a > b
            print 'a is greater'
            print 'b is smaller'

        # If-else statement
        # See also: "Make An If Else Ladder" How To
        if a > b
            print 'a is greater'
        else
            print 'a is not greater'

        # Can put target on same line if the target is just one statement
        if a > b, print 'a is greater'
        else, print 'b is greater or equal'

        # While loop
        while a > b
            a -= 1  # augmented assignment
        
        # While loop in one line
        while a > b, a -= 1

        # Parallel assignment
        a, b = 1, 2
        
        # Lists -- see the "Use Lists" How To for more info
        t = ['a', 'b', 'c']
        for letter in t, print letter

        # Dictionaries
        d = {'a': 1, 'b': 2}
        assert d['a'] == 1 and d['b'] == 2
        for key, value in d
            print '[key] = [value]'  # string interpolation

        # Sets -- like lists, but no repetition
        letters = {'a', 'b', 'c'}
        assert 'a' in letters
        for letter in letters, print letter

        # Line continuation is implicit with parenthesized arguments
        p = Person('Bob',
                    30)

        # Line continuation can be done explicitly with an underscore
        # The next line is indented the same or more
        b = a *  _
            10