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.
47 lines
965 B
Go
47 lines
965 B
Go
// Copyright (c) 2024-2026 Celestino Amoroso (celestino.amoroso@gmail.com).
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// All rights reserved.
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// operand-var.go
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package expr
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import (
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"fmt"
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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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)
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// -------- variable term
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func newVarTerm(tk *scan.Token) *scan.Term {
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t := &scan.Term{
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Tk: *tk,
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Parent: nil,
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Children: nil,
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Position: scan.PosLeaf,
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Priority: scan.PriValue,
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EvalFunc: evalVar,
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}
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t.Tk.Sym = sym.SymVariable
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return t
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}
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// -------- eval func
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func evalVar(ctx kern.ExprContext, opTerm *scan.Term) (v any, err error) {
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var exists bool
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name := opTerm.Source()
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if v, exists = ctx.GetVar(name); !exists {
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if info, exists := ctx.GetFuncInfo(name); exists {
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v = info.Functor()
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} else {
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err = fmt.Errorf("undefined variable or function %q", name)
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}
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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.SymIdentifier, newVarTerm)
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}
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