added info about tuples, integrated wild card use into a function def…

…inition

haskell.html.markdown

@@ -124,6 +124,9 @@ last [1..5] -- 5
 fst ("haskell", 1) -- "haskell"
 snd ("haskell", 1) -- 1
 
+-- pair element accessing does not work on n-tuples (i.e. triple, quadruple, etc)
+snd ("snd", "can't touch this", "da na na na") -- error! see function below to get around this
+
 ----------------------------------------------------
 -- 3. Functions
 ----------------------------------------------------
@@ -159,8 +162,8 @@ fib 1 = 1
 fib 2 = 2
 fib x = fib (x - 1) + fib (x - 2)
 
--- Pattern matching on tuples:
-foo (x, y) = (x + 1, y + 2)
+-- Pattern matching on tuples, using wild card (_) to bypass naming an unused value
+sndOfTriple (_, y, _) = y
 
 -- Pattern matching on lists. Here `x` is the first element
 -- in the list, and `xs` is the rest of the list. We can write
@@ -203,9 +206,9 @@ foo = (4*) . (10+)
 foo 5 -- 60
 
 -- fixing precedence
--- Haskell has an operator called `$`. This operator applies a function 
--- to a given parameter. In contrast to standard function application, which 
--- has highest possible priority of 10 and is left-associative, the `$` operator 
+-- Haskell has an operator called `$`. This operator applies a function
+-- to a given parameter. In contrast to standard function application, which
+-- has highest possible priority of 10 and is left-associative, the `$` operator
 -- has priority of 0 and is right-associative. Such a low priority means that
 -- the expression on its right is applied as the parameter to the function on its left.
 
@@ -223,7 +226,7 @@ even . fib $ 7 -- false
 -- 5. Type signatures
 ----------------------------------------------------
 
--- Haskell has a very strong type system, and every valid expression has a type. 
+-- Haskell has a very strong type system, and every valid expression has a type.
 
 -- Some basic types:
 5 :: Integer