pencelab

panel {
    val square = square {
        lines = 8
        char = 'd'
    }
    space()
    val triangle = triangle {
        lines = 8
        char = 'd'
    }

pencelab

infix fun Shape.intersection(shape: Shape): ComposedShape {
    return ComposedShape(this, shape, ComposedShape.Operation.INTERSECTION)
}

pencelab

infix fun Shape.union(shape: Shape): ComposedShape {
    return ComposedShape(this, shape, ComposedShape.Operation.UNION)
}

pencelab

panel {
    val square = square {
        lines = 8
        char = 'd'
    }
    space()
    val triangle = triangle {
        lines = 8
        char = 'd'
    }

pencelab

panel {
    val square = square {
        lines = 8
        char = 'd'
    }
    space()
    val triangle = triangle {
        lines = 8
        char = 'd'
    }

pencelab

fun Panel.space() {
    this.addShape(Space)
}

pencelab

class RhombusBuilder: ShapeBuilder() {
    override fun build() = Rhombus(lines, char)
}

pencelab

class TriangleBuilder: ShapeBuilder() {
    override fun build() = Triangle(lines, char)
}

pencelab

class SquareBuilder: ShapeBuilder() {
    override fun build() = Square(lines, char)
}

pencelab

abstract class ShapeBuilder {
    
    private companion object {
        const val DEFAULT_CHAR = '*'
    }

    var char = DEFAULT_CHAR
    var lines = 0

    abstract fun build(): Shape