Strawman for lambdas

Issue #35

Author: rwdougla

sources/modules/functions/lambdas.md

@@ -0,0 +1,110 @@
+## Module name: Lambdas
+
+_Skeleton descriptions are typeset in italic text,_
+_so please don't remove these descriptions when editing the topic._
+
+### Overview
+
+_Provides a short natural language abstract of the module’s contents._
+_Specifies the different levels of teaching._
+
+------------------------------------------------------------------------
+Level             Objective
+----------------- ------------------------------------------------------
+Foundational      Define and execute lambdas with basic capture syntax
+
+Main              Passing instances of lambdas for use in external code
+
+Advanced          Generic lambdas, utilizing mutable state, mapping 
+                  to function objects, decay to function pointers
+
+------------------------------------------------------------------------
+
+### Motivation
+
+_Why is this important?_
+_Why do we want to learn/teach this topic?_
+
+* function objects in relation to the standard library...
+* Allows the developer to define and pass functionality as values/data/information
+* Allows developer to operate in a functional-programming mindset
+* Improves code readdability by localizing the code
+* Effective means to help refactoring code from long functions to re-usable functions
+* Library designs taking callables allows the library to be customizable for the consumer, while lambdas make this usage approachable
+
+### Topic introduction
+
+_Very brief introduction to the topic._
+
+Lambdas were added in C++11 and have grown in power and functionality ever since.
+
+### Foundational: Define and execute lambdas with basic capture syntax
+
+#### Background/Required Knowledge
+
+A student:
+_TODO: Add cross-reference to these
+Explain capture-by-value and capture-by-reference
+
+#### Student outcomes
+
+_A list of things "a student should be able to" after the curriculum._
+_The next word should be an action word and testable in an exam._
+_Max 5 items._
+
+A student should be able to:
+
+1. Use a lambda taking a concrete type as a parameter and return a value in response
+2. 
+3. 
+4. 
+5. 
+
+#### Caveats
+
+_This section mentions subtle points to understand, like anything resulting in
+implementation-defined, unspecified, or undefined behavior._
+
+#### Points to cover
+
+_This section lists important details for each point._
+
+### Main: Passing instances of lambdas for use in external code
+
+#### Background/Required Knowledge
+
+* All of the above.
+
+#### Student outcomes
+
+A student should be able to:
+
+1. Utilize std::function as a means to hold and transfer lambdas
+2. Define a function-template taking a lambda as a template parameter
+3. Use captures to change
+
+#### Caveats
+
+#### Points to cover
+
+Capture can introduce new names
+```
+char const* const s = "5";
+[x=atoi(s)](){}
+```
+
+```
+std::ranges::for_each(
+	std::vector{1,2,3,4,5},
+	[init = true] (auto&& x) mutable {
+		if (init) 
+		{ std::cout << x; init = false}; 
+		else 
+		{ std::cout << ',' << x;}
+	});
+```
+
+### Advanced
+Explain why they can't write out the type of a lambda?
+_These are important topics that are not expected to be covered but provide
+guidance where one can continue to investigate this topic in more depth._