Class: Dhall::ExpressionVisitor

Inherits:
Object
  • Object
show all
Defined in:
lib/dhall/normalize.rb

Constant Summary collapse

ExpressionHash = 
Util::HashOf.new(
	ValueSemantics::Anything,
	ValueSemantics::Either.new([Expression, nil])
)
ExpressionArray = 
Util::ArrayOf.new(Expression)

Instance Method Summary collapse

Constructor Details

#initialize(&block) ⇒ ExpressionVisitor

Returns a new instance of ExpressionVisitor.



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# File 'lib/dhall/normalize.rb', line 15

def initialize(&block)
	@block = block
end

Instance Method Details

#one_visit(value) ⇒ Object 



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# File 'lib/dhall/normalize.rb', line 26

def one_visit(value)
	case value
	when Expression
		@block[value]
	when ExpressionArray
		value.map(&@block)
	when ExpressionHash
		Hash[value.map { |k, v| [k, v.nil? ? v : @block[v]] }.sort]
	end
end

#visit(expr) ⇒ Object 



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# File 'lib/dhall/normalize.rb', line 19

def visit(expr)
	expr.to_h.each_with_object({}) do |(attr, value), h|
		result = one_visit(value)
		h[attr] = result if result
	end
end