96 lines
2.1 KiB
Go
96 lines
2.1 KiB
Go
// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
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// All rights reserved.
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// operator-insert.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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//-------- prepend term
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func newPrependTerm(tk *Token) (inst *term) {
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return &term{
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tk: *tk,
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children: make([]*term, 0, 2),
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position: posInfix,
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priority: priInsert,
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evalFunc: evalPrepend,
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}
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}
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func newAppendTerm(tk *Token) (inst *term) {
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return &term{
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tk: *tk,
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children: make([]*term, 0, 2),
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position: posInfix,
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priority: priInsert,
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evalFunc: evalAppend,
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}
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}
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func evalPrepend(ctx kern.ExprContext, opTerm *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 kern.IsList(rightValue) {
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list, _ := rightValue.(*kern.ListType)
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newList := append(kern.ListType{leftValue}, *list...)
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v = &newList
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if opTerm.children[1].symbol() == SymVariable {
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ctx.UnsafeSetVar(opTerm.children[1].Source(), v)
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}
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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 evalAppend(ctx kern.ExprContext, opTerm *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 kern.IsList(leftValue) {
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list, _ := leftValue.(*kern.ListType)
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newList := append(*list, rightValue)
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v = &newList
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if opTerm.children[0].symbol() == SymVariable {
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ctx.UnsafeSetVar(opTerm.children[0].Source(), v)
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}
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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 evalAssignAppend(ctx ExprContext, self *term) (v any, err error) {
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// var leftValue, rightValue any
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// if leftValue, rightValue, err = self.evalInfix(ctx); err != nil {
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// return
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// }
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// if IsList(leftValue) {
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// list, _ := leftValue.(*ListType)
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// newList := append(*list, rightValue)
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// v = &newList
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// if
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// } else {
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// err = self.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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registerTermConstructor(SymPlusGreater, newPrependTerm)
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registerTermConstructor(SymLessPlus, newAppendTerm)
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}
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