63 lines
1.2 KiB
Go
63 lines
1.2 KiB
Go
// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
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// All rights reserved.
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// operator-sign.go
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package expr
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//-------- plus sign term
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func newPlusSignTerm(tk *Token) (inst *term) {
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return &term{
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tk: *tk,
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// class: classOperator,
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// kind: kindUnknown,
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children: make([]*term, 0, 1),
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position: posPrefix,
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priority: priSign,
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evalFunc: evalSign,
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}
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}
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func newMinusSignTerm(tk *Token) (inst *term) {
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return &term{
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tk: *tk,
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children: make([]*term, 0, 1),
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position: posPrefix,
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priority: priSign,
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evalFunc: evalSign,
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}
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}
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func evalSign(ctx ExprContext, opTerm *term) (v any, err error) {
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var rightValue any
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if rightValue, err = opTerm.evalPrefix(ctx); err != nil {
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return
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}
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if IsFloat(rightValue) {
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if opTerm.tk.Sym == SymChangeSign {
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f, _ := rightValue.(float64)
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v = -f
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} else {
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v = rightValue
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}
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} else if IsInteger(rightValue) {
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if opTerm.tk.Sym == SymChangeSign {
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i, _ := rightValue.(int64)
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v = -i
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} else {
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v = rightValue
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}
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} else {
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err = opTerm.errIncompatibleType(rightValue)
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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(SymUnchangeSign, newPlusSignTerm)
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registerTermConstructor(SymChangeSign, newMinusSignTerm)
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}
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