CSC/ECE 517 Fall 2011/ch1 1d sr
Wiki Chapter: CSC/ECE 517 Fall 2011/ch1 1d sr
Introduction
Closures
What are Closures
Let us try to define what a closure as a programming construct means.
A Closure is basically a function or a method (or a block, in the context of ruby) that has the following two properties -
• One can pass it around like an object or as a value parameter to other functions/methods/blocks
• It takes the snapshot and effectively "remembers" the values of all the variables that were in scope when the function was created
and it is because of this property that it is able to access those variables when it is called even though they may no longer in scope. [1]
Why Closures (Motivation, Uses, Advantages)
Closures in Dynamically Typed Languages
Example use of Closures in Dynamically Typed Langauges
Example in Ruby
Example in JS
Example in Python
Closures in Statically Typed Languages
The Problem
Limitations of Statically Typed Languages
Lexical Scope
Functions not as first class citizens of the language
Implementing Closures in Statically Typed Languages
C : function pointers
C++ : function objects
Java : anonymous inner classes
Closures and Static Scoping
(Explanation)
Case study of Scheme
References
1. Matz discussion on Closures