[Python-ideas] Jump to function as an an alternative to call function

Jacob Solinsky jacobsolinsky at gmail.com
Wed Aug 15 14:52:27 EDT 2018


-Jumping to a function as opposed to calling a function

When a function is jumped to, it inherits the variables in the caller’s local namespace and is free to modify them or add new local variables, unlike a normal function call, wherein the caller’s namespace is inaccesible. At present, the only way I know of to accomplish this is to bundle all variables in the caller method’s namespace as properties of the method’s instance and have the callee method modify those properties. Though it is easier to read code written this way, it resulted in a great deal of redundancy in the code I was writing. The task I was attempting to accomplish was approximately this:

class Verb:
	def __init__(self, parameters):
		self.parameters = parameters
	def conjugate(self):
		#Using the parameters, chose an appropriate list of morphemes to prefix and suffix to the verb
		self.morphemelist = morphemelist
		for morpheme in self.morphemelist:
			morpheme.mutate()
		returnstring = ‘'
		for morpheme in self.morphemelist:
			returnstring = returnstring + morpheme.form
		returnstring = returnstring

class Morpheme:
	def __init__(self, verb, form, precedingmorpheme, succeedingmorpheme):
		self.verb = verb
		self.form = form
		self.precedingmorpheme = precedingmorpheme
		self.succeedingmorpheme = succeedingmorpheme
	def mutate(self): 
		#Using the verb’s parameters and the type and form of the preceding and succeeding morpheme, mutate this morpheme’s form so that  		#a correct verb form is produced
		self.form = newform

class Ban(Morpheme):
	def __init__(self, verb, form):
		super().__init__(verb, ‘ban’)
	def mutate(self):
		#This morpheme has mutation logic unique to itself but with many similarities to the default morpheme’s mutation logic
		self.form = newform

Each subclass of Morpheme has its own slightly different mutate method. Some subclasses of Morpheme needed to access and manipulate a great deal of information about the verb and their surroundings, while other subclasses’ mutate methods differed little from the default. Most of the variables manipulated by the mutate method are not used by any other methods of class Morpheme and thus should not be made properties of the attached instance. What I wish I were able to do is write many little methods that modify the same set of local variables and compose them together into a complete mutate method. This would be effectively equivalent to having the “jump to function” calls be replaced with the text in the function’s body, like a C language macrosubstitution, but without using anything like preprocessor directives.

Let foo(a, b) be the syntax to call foo(a, b), and foo(a, b)% be the syntax to jump to foo(a, b)

def foo(a):
	return a + c

def bar(a, c):
	return foo(a)

def bazz(a, c):
	return foo(a)%

c = 5

call = bar(1, 3)

jump = bazz(1, 3)


After execution, call in the above code would be 6 and jump in the above code would be 4.




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