49 lines
1.2 KiB
Ruby
49 lines
1.2 KiB
Ruby
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# Used internally for representing a bind placeholder in a Parslet::Transform
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# pattern. This is the superclass for all bindings.
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#
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# It defines the most permissive kind of bind, the one that matches any subtree
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# whatever it looks like.
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#
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class Parslet::Pattern::SubtreeBind < Struct.new(:symbol)
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def variable_name
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symbol
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end
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def inspect
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"#{bind_type_name}(#{symbol.inspect})"
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end
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def can_bind?(subtree)
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true
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end
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private
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def bind_type_name
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if md=self.class.name.match(/(\w+)Bind/)
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md.captures.first.downcase
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else
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# This path should never be used, but since this is for inspection only,
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# let's not raise.
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'unknown_bind'
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end
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end
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end
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# Binds a symbol to a simple subtree, one that is not either a sequence of
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# elements or a collection of attributes.
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#
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class Parslet::Pattern::SimpleBind < Parslet::Pattern::SubtreeBind
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def can_bind?(subtree)
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not [Hash, Array].include?(subtree.class)
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end
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end
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# Binds a symbol to a sequence of simple leafs ([element1, element2, ...])
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#
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class Parslet::Pattern::SequenceBind < Parslet::Pattern::SubtreeBind
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def can_bind?(subtree)
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subtree.kind_of?(Array) &&
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(not subtree.any? { |el| [Hash, Array].include?(el.class) })
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end
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end
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