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