pencelab

inline fun Panel.square(init: SquareBuilder.() -> Unit): Square {
    return SquareBuilder().apply { init() }.build().also { this.addShape(it) }
}

pencelab

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

pencelab

inline fun panel(init: (@ShapeDsl Panel).() -> Unit): Panel {
    return Panel().apply { init() }
}

inline fun Panel.square(init: (@ShapeDsl SquareBuilder).() -> Unit): Square {
    return SquareBuilder().apply { init() }.build().also { this.addShape(it) }
}

pencelab

@DslMarker
@Target(AnnotationTarget.CLASS, AnnotationTarget.TYPE)
annotation class ShapeDsl

pencelab

panel {
    square {
        lines = 8
        char = 'd'
        
        square {
            lines = 5
            char = 'o'
            
            triangle {

pencelab

inline fun panel(init: Panel.() -> Unit): Panel {
    return Panel().apply { init() }
}

inline fun Panel.square(init: SquareBuilder.() -> Unit): Square {
    return SquareBuilder().apply { init() }.build().also { this.addShape(it) }
}

inline fun Panel.triangle(init: TriangleBuilder.() -> Unit): Triangle {
    return TriangleBuilder().apply { init() }.build().also { this.addShape(it) }

pencelab

operator fun Shape.plus(shape: Shape): ComposedShape = this union shape

operator fun Shape.minus(shape: Shape): ComposedShape = this intersection shape

pencelab

panel {
    val square = square {
        lines = 8
        char = 'd'
    }
    space()
    val triangle = triangle {
        lines = 7
        char = 's'
    }

pencelab

panel {
    ...
    space()
    addShape(square union rhombus)
    ...
    space()
    composed { ComposedShape(rhombus, triangle, ComposedShape.Operation.INTERSECTION) }
    ...
}.print()

pencelab

fun Panel.composed(init: Panel.() -> ComposedShape): ComposedShape {
    return init().also { this.addShape(it) }
}