camoroso
8e596d5979
1. moved scan/symbol.go to new package sym and adapted all files that reference Symbol type and its values. 2. new type interval defined by begin, end and step values. 3. replaced operator-range.go with operator-interval.go. 4. replaced range operator begin:end with begin..end..step. 5. new implementation of sub-collection extraction based on new interval literal.
69 lines
1.5 KiB
Go
69 lines
1.5 KiB
Go
// Copyright (c) 2024-2026 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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import (
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"git.portale-stac.it/go-pkg/expr/kern"
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"git.portale-stac.it/go-pkg/expr/scan"
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"git.portale-stac.it/go-pkg/expr/sym"
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"git.portale-stac.it/go-pkg/expr/types"
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"git.portale-stac.it/go-pkg/expr/types/float"
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)
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//-------- plus sign term
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func newPlusSignTerm(tk *scan.Token) (inst *scan.Term) {
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return &scan.Term{
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Tk: *tk,
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Children: make([]*scan.Term, 0, 1),
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Position: scan.PosPrefix,
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Priority: scan.PriSign,
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EvalFunc: evalSign,
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}
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}
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func newMinusSignTerm(tk *scan.Token) (inst *scan.Term) {
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return &scan.Term{
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Tk: *tk,
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Children: make([]*scan.Term, 0, 1),
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Position: scan.PosPrefix,
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Priority: scan.PriSign,
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EvalFunc: evalSign,
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}
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}
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func evalSign(ctx kern.ExprContext, opTerm *scan.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 float.IsFloat(rightValue) {
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if opTerm.Tk.Sym == 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 types.IsInteger(rightValue) {
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if opTerm.Tk.Sym == 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.ErrIncompatiblePrefixPostfixType(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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scan.RegisterTermConstructor(sym.SymUnchangeSign, newPlusSignTerm)
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scan.RegisterTermConstructor(sym.SymChangeSign, newMinusSignTerm)
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}
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