74 lines
1.6 KiB
Go
74 lines
1.6 KiB
Go
// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
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// All rights reserved.
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// operator-post-inc-dec.go
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package expr
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// -------- post increment term
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func newPostIncTerm(tk *Token) *term {
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return &term{
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tk: *tk,
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parent: nil,
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children: make([]*term, 0, 1),
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position: posPostfix,
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priority: priIncDec,
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evalFunc: evalPostInc,
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}
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}
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func evalPostInc(ctx ExprContext, opTerm *term) (v any, err error) {
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var childValue any
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if childValue, err = opTerm.evalPrefix(ctx); err != nil {
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return
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}
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if it, ok := childValue.(Iterator); ok {
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v, err = it.Next()
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} else if IsInteger(childValue) && opTerm.children[0].symbol() == SymVariable {
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v = childValue
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i, _ := childValue.(int64)
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ctx.SetVar(opTerm.children[0].source(), i+1)
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} else {
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err = opTerm.errIncompatibleType(childValue)
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}
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return
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}
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// -------- post decrement term
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func newPostDecTerm(tk *Token) *term {
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return &term{
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tk: *tk,
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parent: nil,
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children: make([]*term, 0, 1),
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position: posPostfix,
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priority: priIncDec,
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evalFunc: evalPostDec,
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}
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}
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func evalPostDec(ctx ExprContext, opTerm *term) (v any, err error) {
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var childValue any
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if childValue, err = opTerm.evalPrefix(ctx); err != nil {
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return
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}
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/* if it, ok := childValue.(Iterator); ok {
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v, err = it.Next()
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} else */if IsInteger(childValue) && opTerm.children[0].symbol() == SymVariable {
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v = childValue
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i, _ := childValue.(int64)
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ctx.SetVar(opTerm.children[0].source(), i-1)
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} else {
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err = opTerm.errIncompatibleType(childValue)
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}
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return
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}
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// init
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func init() {
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registerTermConstructor(SymDoublePlus, newPostIncTerm)
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registerTermConstructor(SymDoubleMinus, newPostDecTerm)
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}
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