20 lines
489 B
Go
20 lines
489 B
Go
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package evaluator
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import "monkey/object"
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var builtins = map[string]*object.Builtin{
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"len": &object.Builtin{
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Fn: func(args ...object.Object) object.Object {
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if len(args) != 1 {
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return new_error("wrong number of arguments, got=%d, want=1", len(args))
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}
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switch arg := args[0].(type) {
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case *object.String:
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return &object.Integer{Value: int64(len(arg.Value))}
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default:
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return new_error("argument to `len` not supported, got %s", args[0].Type())
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}
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},
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},
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}
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