expr/operator-iter-value.go

39 lines
811 B
Go

// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
// All rights reserved.
// operator-iter-value.go
package expr
//-------- iter value term
func newIterValueTerm(tk *Token) (inst *term) {
return &term{
tk: *tk,
children: make([]*term, 0, 1),
position: posPrefix,
priority: priDereference,
evalFunc: evalIterValue,
}
}
func evalIterValue(ctx ExprContext, opTerm *term) (v any, err error) {
var childValue any
if childValue, err = opTerm.evalPrefix(ctx); err != nil {
return
}
if it, ok := childValue.(Iterator); ok {
v, err = it.Current()
} else {
err = opTerm.errIncompatibleType(childValue)
}
return
}
// init
func init() {
// registerTermConstructor(SymOpenClosedRound, newIterValueTerm)
registerTermConstructor(SymDereference, newIterValueTerm)
}