42 lines
678 B
Ruby
42 lines
678 B
Ruby
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class Parslet::Scope
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# Raised when the accessed slot has never been assigned a value.
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#
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class NotFound < StandardError
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end
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class Binding
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attr_reader :parent
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def initialize(parent=nil)
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@parent = parent
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@hash = Hash.new
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end
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def [](k)
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@hash.has_key?(k) && @hash[k] ||
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parent && parent[k] or
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raise NotFound
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end
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def []=(k,v)
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@hash.store(k,v)
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end
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end
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def [](k)
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@current[k]
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end
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def []=(k,v)
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@current[k] = v
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end
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def initialize
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@current = Binding.new
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end
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def push
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@current = Binding.new(@current)
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end
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def pop
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@current = @current.parent
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end
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end
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