doc: a heck-ton more expressions for the sample file :)

doc/sample/Expressions.im

@@ -51,10 +51,61 @@ for i in 0 to:100 step:2 do
 end
 
 cout put:"message" while x > 2.
-cout put:"Count is {i}" for i in 0 to:100 step:2.
+cout put:'Count is {i}' for i in 0 to:100 step:2.
 
 z = do
     x = 1.
     y = 2.
     ^x + y
 end.
+
+class Person
+    /**
+        every message handler can have one or both of the following:
+        - a message name (in this case, 'init')
+        - a set of one or more parameters (wrapped in parentheses if the message
+          has a name)
+
+        each parameter has an internal name and an (optional) label, specified
+        as a pair of identifiers separated by a colon (:). the label comes
+        first, and is the name used by whoever is sending the message the
+        internal name comes second, and is used by the message handler itself as
+        a variable name.
+
+        you can omit the label for a parameter by specifying an underscore (_)
+        as the label, but this is not recommended. it looks weird, it obscures
+        the meaning of the message, and is really only supported for
+        compatibility with lambdas.
+    **/
+    - init(name:name age:age)
+        self::name = name.
+        self::age = age!
+
+    - test(param:data _:extra) | cout put:'Received {data}, {extra}'.
+
+    - name | ^self::name.
+
+    - age | ^self::age.
+
+    - ageInMonths | ^self::age * 12.
+
+    - setName:name | self::name = name.
+
+    - setAge:age | self::age = age.
+
+    - setAge:age inUnit:units
+        match units in
+            #years  => self::age = age,
+            #months => self::age = age / 12,
+            #days   => self::age = age / 365,
+            _       => self::age = 0
+        end!
+
+    - getAgeInUnit:units
+        ^match units in
+            #years  => self::age,
+            #months => self::age / 12,
+            #days   => self::age / 365,
+            _       => 0
+        end!
+end