diff options
Diffstat (limited to 'haskell.html.markdown')
| -rw-r--r-- | haskell.html.markdown | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/haskell.html.markdown b/haskell.html.markdown index 2785405c..748a29da 100644 --- a/haskell.html.markdown +++ b/haskell.html.markdown @@ -110,7 +110,7 @@ last [1..5] -- 5 -- A tuple: ("haskell", 1) --- accessing elements of a tuple +-- accessing elements of a pair (i.e. a tuple of length 2) fst ("haskell", 1) -- "haskell" snd ("haskell", 1) -- 1 @@ -195,8 +195,8 @@ foo 5 -- 75 -- fixing precedence -- Haskell has another function called `$`. This changes the precedence -- so that everything to the left of it gets computed first and then applied --- to everything on the right. You can use `.` and `$` to get rid of a lot --- of parentheses: +-- to everything on the right. You can use `$` (often in combination with `.`) +-- to get rid of a lot of parentheses: -- before (even (fib 7)) -- true @@ -204,6 +204,9 @@ foo 5 -- 75 -- after even . fib $ 7 -- true +-- equivalently +even $ fib 7 -- true + ---------------------------------------------------- -- 5. Type signatures ---------------------------------------------------- @@ -227,24 +230,24 @@ double :: Integer -> Integer double x = x * 2 ---------------------------------------------------- --- 6. Control Flow and If Statements +-- 6. Control Flow and If Expressions ---------------------------------------------------- --- if statements +-- if expressions haskell = if 1 == 1 then "awesome" else "awful" -- haskell = "awesome" --- if statements can be on multiple lines too, indentation is important +-- if expressions can be on multiple lines too, indentation is important haskell = if 1 == 1 then "awesome" else "awful" --- case statements: Here's how you could parse command line arguments +-- case expressions: Here's how you could parse command line arguments case args of "help" -> printHelp "start" -> startProgram _ -> putStrLn "bad args" --- Haskell doesn't have loops because it uses recursion instead. +-- Haskell doesn't have loops; it uses recursion instead. -- map applies a function over every element in an array map (*2) [1..5] -- [2, 4, 6, 8, 10] |