57 lines
1.3 KiB
Go
57 lines
1.3 KiB
Go
// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
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// All rights reserved.
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// operator-length.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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)
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//-------- length term
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func newLengthTerm(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: evalLength,
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}
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}
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func evalLength(ctx kern.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 kern.IsList(childValue) {
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ls, _ := childValue.(*kern.ListType)
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v = int64(len(*ls))
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} else if kern.IsString(childValue) {
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s, _ := childValue.(string)
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v = int64(len(s))
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} else if kern.IsDict(childValue) {
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m, _ := childValue.(*kern.DictType)
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v = int64(len(*m))
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} else if it, ok := childValue.(kern.Iterator); ok {
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v = int64(it.Count())
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// if extIt, ok := childValue.(ExtIterator); ok && extIt.HasOperation(CountName) {
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// count, _ := extIt.CallOperation(CountName, nil)
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// v, _ = ToGoInt(count, "")
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// } else {
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// v = int64(it.Index() + 1)
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// }
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} else {
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err = opTerm.errIncompatiblePrefixPostfixType(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(SymHash, newLengthTerm)
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}
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