46 lines
973 B
Go
46 lines
973 B
Go
// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
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// All rights reserved.
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// operator-assign.go
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package expr
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//-------- assign term
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func newAssignTerm(tk *Token) (inst *term) {
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return &term{
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tk: *tk,
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class: classOperator,
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kind: kindUnknown,
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children: make([]*term, 0, 2),
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position: posInfix,
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priority: priAssign,
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evalFunc: evalAssign,
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}
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}
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func evalAssign(ctx exprContext, self *term) (v any, err error) {
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if err = self.checkOperands(); err != nil {
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return
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}
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leftTerm := self.children[0]
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if leftTerm.tk.Sym != SymIdentifier {
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err = leftTerm.tk.Errorf("left operand of %q must be a variable", self.tk.source)
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return
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}
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if v, err = self.children[1].compute(ctx); err == nil {
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if functor, ok := v.(Functor); ok {
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ctx.RegisterFunc(leftTerm.source(), functor, 0, -1)
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} else {
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ctx.SetVar(leftTerm.tk.source, v)
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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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registerTermConstructor(SymEqual, newAssignTerm)
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}
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