// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
// All rights reserved.

// operator-post-inc.go
package expr

// -------- post increment term

func newPostIncTerm(tk *Token) *term {
	return &term{
		tk:       *tk,
		parent:   nil,
		children: make([]*term, 0, 1),
		position: posPostfix,
		priority: priPrePost,
		evalFunc: evalPostInc,
	}
}

func evalPostInc(ctx ExprContext, self *term) (v any, err error) {
	var leftValue any
	if leftValue, err = self.evalPrefix(ctx); err != nil {
		return
	}

	if dc, ok := leftValue.(*dataCursor); ok {
		v, err = dc.Next()
	} else if isInteger(leftValue) && self.children[0].symbol() == SymIdentifier {
		v = leftValue
		i, _ := leftValue.(int64)
		ctx.SetVar(self.children[0].source(), i+1)
	} else {
		self.errIncompatibleType(leftValue)
	}
	return
}

// init
func init() {
	registerTermConstructor(SymDoublePlus, newPostIncTerm)
}