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3-99 Research/Haskell/Chapter 2 - Starting Out.md

@@ -119,6 +119,21 @@ take 10 [2, 4..]
 -- will only yield even numbers greater than 12 in the first 10 elements of the set
 ```
 
-I made it to boomBangs and stopped. I'm outta gas :) 
+boomBangs is an interesting one. We can write code that does a function as the function, while also incorporating predicates.
 
+An easy way to remember: [Function | Set, Predicate, (predicate 2),...]
+Fucking Stupid Predicates
+
+We can also use multiple lists. If multiple lists are given (one for each variable), then all combinations of the two lists are used.
+
+Strings are just lists. We can apply list comprehensions to them!
+Here's a couple of useful examples:
+```haskell
+-- Now Writing our own custom list function
+length' xs = sum [1 | _ <- xs] 
+-- use dummy variable _, draw an element from a list and replace it with 1. Sum all of those.
+
+--- Strings are lists! We can use list comprehensions on them.
+removeNonUppercase st = [ c | c <- st, c `elem` ['A'..'Z']]
+```
 

3-99 Research/Haskell/baby.hs

@@ -18,3 +18,6 @@ schtankyList x = [ x*y | x <- [2,5,10], y <- [8,10,11]]
 length' xs = sum [1 | _ <- xs] 
 -- use dummy variable _, draw an element from a list and replace it with 1. Sum all of those.
 
+--- Strings are lists! We can use list comprehensions on them.
+removeNonUppercase st = [ c | c <- st, c `elem` ['A'..'Z']]
+