Module: Dhallish::Types

Defined in:
lib/types.rb

Defined Under Namespace

Classes: Function, List, Optional, Record, Type, Union, Unresolved

Constant Summary collapse

Natural = 
:Natural
Integer = 
:Integer
Double = 
:Double
Bool = 
:Bool
Text = 
:Text
Numbers = 
[Natural, Integer, Double]
TextList = 
List.new(Text)
NaturalList = 
List.new(Natural)
IntegerList = 
List.new(Integer)
DoubleList = 
List.new(Double)

Class Method Summary collapse

Class Method Details

.is_a_type?(x) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/types.rb', line 280

def is_a_type?(x)
	!not_a_type?(x)
end

.not_a_type?(x) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/types.rb', line 271

def not_a_type?(x)
	if x.is_a? Symbol
		x != Natural and x != Integer and x != Double and x != Bool and x != Text
	else
		!x.is_a? Optional and !x.is_a? List and !x.is_a? Record and !x.is_a? Function and !x.is_a? Unresolved and !x.is_a? Type and !x.is_a? Union
	end
end

.resolve(orgtype, name, newtype) ⇒ Object 



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# File 'lib/types.rb', line 152

def resolve(orgtype, name, newtype)
	case orgtype
	when Type
		Type.new(resolve(orgtype.metadata, name, newtype))
	when Unresolved
		if name == orgtype.name
			newtype
		else
			orgtype
		end
	when Function
		if orgtype.restype.nil?
			Function.new(resolve(orgtype.argtype, name, newtype), nil, orgtype.unres)
		else
			restype = orgtype.restype
			argtype = orgtype.argtype
			if orgtype.unres.nil? or orgtype.unres != name
				restype = resolve(orgtype.restype, name, newtype)
				argtype = resolve(orgtype.argtype, name, newtype)
			end
			Function.new(argtype, restype, orgtype.unres)
		end
	when Optional
		Optional.new(resolve(orgtype.type, name, newtype))
	when List
		List.new(resolve(orgtype.type, name, newtype))
	when Record
		Record.new(orgtype.types.map{ |key, val| [key, resolve(val, name, newtype)] }.to_h)
	when Union
		Union.new(orgtype.types.map{ |key, val| [key, resolve(val, name, newtype)] }.to_h)
	else
		orgtype
	end
end

.unification(a, b, mapping = {}) ⇒ Object 



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# File 'lib/types.rb', line 188

def unification(a, b, mapping={})
	case a
	when Type
		if b.is_a? Type
			unification(a.metadata, b.metadata, mapping)
		else
			nil
		end
	when Unresolved
		if b.is_a? Unresolved
			if mapping[a.name] == nil
				mapping[a.name] = b.name
				mapping
			elsif mapping[a.name] != b.name
				nil
			else
				mapping
			end
		else
			nil
		end
	when Function
		if b.is_a? Function
			if unification(a.argtype, b.argtype, mapping).nil?
				nil
			else
				arestype = a.restype
				brestype = b.restype
				if !a.unres.nil?; arestype = resolve(a.restype, a.unres, Unresolved.new(get_new_sym())) end
				if !b.unres.nil?; brestype = resolve(b.restype, b.unres, Unresolved.new(get_new_sym())) end
				unification(arestype, brestype, mapping)
			end
		else
			nil
		end
	when Optional
		if b.is_a? Optional
			unification(a.type, b.type, mapping)
		else
			nil
		end
	when List
		if b.is_a? List
			unification(a.type, b.type, mapping)
		else
			nil
		end
	when Record
		if b.is_a? Record and a.types.keys.length == b.types.keys.length
			for key in a.types.keys
				aelm = a.types[key]
				belm = b.types[key]
				if belm.nil?; return nil end
				ret = unification(aelm, belm, mapping)
				if ret.nil?; return nil end
			end
			mapping
		else
			nil
		end
	when Union
		if b.is_a? Union and a.types.keys.length == b.types.keys.length
			for key in a.types.keys
				aelm = a.types[key]
				belm = b.types[key]
				if belm.nil?; return nil end
				ret = unification(aelm, belm, mapping)
				if ret.nil?; return nil end
			end
			mapping
		else
			nil
		end
	else
		if a == b
			mapping
		else
			nil
		end
	end
end