87 lines
2.1 KiB
Go
87 lines
2.1 KiB
Go
// Copyright (c) 2024-2026 Celestino Amoroso (celestino.amoroso@gmail.com).
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// All rights reserved.
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// operator-shift.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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)
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//-------- bit right shift term
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func newRightShiftTerm(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.PriBinShift,
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EvalFunc: evalRightShift,
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}
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}
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func bitRightShift(opTerm *scan.Term, leftValue, rightValue any) (v any, err error) {
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if kern.IsInteger(leftValue) && kern.IsInteger(rightValue) {
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leftInt := leftValue.(int64)
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rightInt := rightValue.(int64)
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v = leftInt >> rightInt
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} else {
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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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func evalRightShift(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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if v, err = bitRightShift(opTerm, leftValue, rightValue); err != nil {
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v, err = prependToList(ctx, opTerm, leftValue, rightValue)
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}
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return
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}
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func newLeftShiftTerm(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.PriBinShift,
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EvalFunc: evalLeftShift,
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}
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}
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func bitLeftShift(opTerm *scan.Term, leftValue, rightValue any) (v any, err error) {
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if kern.IsInteger(leftValue) && kern.IsInteger(rightValue) {
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leftInt := leftValue.(int64)
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rightInt := rightValue.(int64)
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v = leftInt << rightInt
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} else {
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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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func evalLeftShift(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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if v, err = bitLeftShift(opTerm, leftValue, rightValue); err != nil {
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v, err = appendToList(ctx, opTerm, 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(scan.SymDoubleGreater, newRightShiftTerm)
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scan.RegisterTermConstructor(scan.SymDoubleLess, newLeftShiftTerm)
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}
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