package saccharine

import "strings"

type stringifyVisitor struct {
	builder strings.Builder
}

func (v *stringifyVisitor) VisitVariable(a *Variable) {
	v.builder.WriteString(a.Name)
}

func (v *stringifyVisitor) VisitAbstraction(f *Abstraction) {
	v.builder.WriteRune('\\')
	v.builder.WriteString(strings.Join(f.Parameters, " "))
	v.builder.WriteRune('.')
	f.Body.Accept(v)
}

func (v *stringifyVisitor) VisitApplication(c *Application) {
	v.builder.WriteRune('(')
	c.Abstraction.Accept(v)

	for _, argument := range c.Arguments {
		v.builder.WriteRune(' ')
		argument.Accept(v)
	}

	v.builder.WriteRune(')')
}

func Stringify(n Node) string {
	b := &stringifyVisitor{}
	n.Accept(b)
	return b.builder.String()
}