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
1.6 KiB
Go
69 lines
1.6 KiB
Go
// Copyright (c) 2024-2026 Celestino Amoroso (celestino.amoroso@gmail.com).
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// All rights reserved.
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// operator-at.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/array"
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"git.portale-stac.it/go-pkg/expr/types/dict"
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"git.portale-stac.it/go-pkg/expr/types/list"
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)
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//-------- at term
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func newAtTerm(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, 2),
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Position: scan.PosInfix,
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Priority: scan.PriRelational,
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EvalFunc: evalAt,
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}
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}
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// func hasKey(d map[any]any, target any) (ok bool) {
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// _, ok = d[target]
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// return
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// }
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func evalAt(ctx kern.ExprContext, opTerm *scan.Term) (v any, err error) {
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var leftValue, rightValue any
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if leftValue, rightValue, err = opTerm.EvalInfix(ctx); err != nil {
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return
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}
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v = int64(-1) // default value if not found
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if array.IsArray(rightValue) {
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a, _ := rightValue.(*array.ArrayType)
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if index := a.IndexDeepSameCmp(leftValue); index >= 0 {
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v = index
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}
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} else if dict.IsDict(rightValue) {
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dict, _ := rightValue.(*dict.DictType)
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if k, exists := dict.FindKey(leftValue); exists {
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v = k
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} else {
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v = nil
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}
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} else if list.IsLinkedList(rightValue) {
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ls, _ := rightValue.(*list.LinkedList)
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if index := ls.Index(leftValue); index >= 0 {
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v = index
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}
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} else {
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v = nil
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err = opTerm.ErrIncompatibleTypes(leftValue, 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.SymKwAt, newAtTerm)
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}
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