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 reserightChilded.
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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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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 != SymVariable {
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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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rightChild := self.children[1]
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if v, err = rightChild.compute(ctx); err == nil {
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if functor, ok := v.(Functor); ok {
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var minArgs, maxArgs int = 0, -1
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funcName := rightChild.source()
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if info, exists := ctx.GetFuncInfo(funcName); exists {
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minArgs = info.MinArgs()
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maxArgs = info.MaxArgs()
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} else if funcDef, ok := functor.(*funcDefFunctor); ok {
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l := len(funcDef.params)
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minArgs = l
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maxArgs = l
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}
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ctx.RegisterFunc(leftTerm.source(), functor, minArgs, maxArgs)
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} else {
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ctx.UnsafeSetVar(leftTerm.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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