diff options
Diffstat (limited to 'standard-ml.html.markdown')
| -rw-r--r-- | standard-ml.html.markdown | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/standard-ml.html.markdown b/standard-ml.html.markdown index c9eb2a2e..e1fe0d19 100644 --- a/standard-ml.html.markdown +++ b/standard-ml.html.markdown @@ -1,5 +1,6 @@ --- language: "Standard ML" +filename: standardml.sml contributors: - ["Simon Shine", "http://shine.eu.org/"] - ["David Pedersen", "http://lonelyproton.com/"] @@ -351,7 +352,10 @@ val _ = print (say(Red) ^ "\n") fun say Red = "You are red!" | say Green = "You are green!" | say Blue = "You are blue!" - | say _ = raise Fail "Unknown color" + +(* We did not include the match arm `say _ = raise Fail "Unknown color"` +because after specifying all three colors, the pattern is exhaustive +and redundancy is not permitted in pattern matching *) (* Here is a binary tree datatype *) @@ -385,7 +389,7 @@ fun calculate_interest(n) = if n < 0.0 (* Exceptions can be caught using "handle" *) val balance = calculate_interest ~180.0 - handle Domain => ~180.0 (* x now has the value ~180.0 *) + handle Domain => ~180.0 (* balance now has the value ~180.0 *) (* Some exceptions carry extra information with them *) (* Here are some examples of built-in exceptions *) @@ -395,7 +399,7 @@ fun failing_function [] = raise Empty (* used for empty lists *) | failing_function xs = raise Fail "This list is too long!" (* We can pattern match in 'handle' to make sure - a specfic exception was raised, or grab the message *) + a specific exception was raised, or grab the message *) val err_msg = failing_function [1,2] handle Fail _ => "Fail was raised" | Domain => "Domain was raised" | Empty => "Empty was raised" |