Class: Dhallish::Ast::FunctionType

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(lhs, rhs, type_var = nil) ⇒ FunctionType

lhs and rhs should be values of type Type if Function Type contains “forall” , e.g. “forall(t : Type) -> Natural”, type_var should contain the introduced label as a string otherwise, type_var shall be nil



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# File 'lib/ast.rb', line 571

def initialize(lhs, rhs, type_var=nil)
	@lhs = lhs
	@rhs = rhs
	@type_var = type_var
end

Instance Attribute Details

#lhs ⇒ Object

Returns the value of attribute lhs.



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# File 'lib/ast.rb', line 564

def lhs
  @lhs
end

#rhs ⇒ Object

Returns the value of attribute rhs.



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# File 'lib/ast.rb', line 565

def rhs
  @rhs
end

#type_var ⇒ Object

Returns the value of attribute type_var.



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# File 'lib/ast.rb', line 566

def type_var
  @type_var
end

Instance Method Details

#compute_type(ctx) ⇒ Object 



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# File 'lib/ast.rb', line 577

def compute_type(ctx)
	lhs_type = @lhs.compute_type ctx
	assert ("Expression for argument type not a type") { lhs_type.is_a? Types::Type }
	lhs_type = lhs_type.metadata
	new_ctx = ctx
	type_var = nil
	if !@type_var.nil? and lhs_type.is_a? Types::Type
		new_ctx = Context.new ctx
		lhs_type = new_ctx[@type_var] = Types::Type.new (Types::Unresolved.new @type_var)
		type_var = @type_var
	end
	rhs_type = @rhs.compute_type new_ctx
	assert ("Expression for result type not a type") { rhs_type.is_a? Types::Type }
	rhs_type = rhs_type.metadata
	Types::Type.new (Types::Function.new lhs_type, rhs_type, type_var)
end

#evaluate(ctx) ⇒ Object 



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# File 'lib/ast.rb', line 594

def evaluate(ctx)
	lhs = @lhs.evaluate(ctx)

	if !type_var.nil? and lhs.is_a? Types::Type
		new_ctx = Context.new(ctx)
		new_ctx[type_var] = Types::Unresolved.new(type_var)
		rhs = @rhs.evaluate(new_ctx)
	else
		rhs = @rhs.evaluate(ctx)
	end

	Types::Function.new(lhs, rhs, type_var)
end