# File eval mode now relies on main function

To encourage organizing code in a way that helps in understanding, I
have implemented the common idiom of requiring a `main` function. In
tricu and other functional languages, it is usually placed near the top
of the module. The evaluator gracefully handles the situation of passing
multiple files where the intermediary "library" files do not have main functions.

demos/equality.tri

@@ -1,3 +1,5 @@
+main = lambdaEqualsTC
+
 -- We represent `false` with a Leaf and `true` with a Stem Leaf
 demo_false = t
 demo_true  = t t

demos/levelOrderTraversal.tri

@@ -1,3 +1,4 @@
+main = exampleTwo
 -- Level Order Traversal of a labelled binary tree
 -- Objective: Print each "level" of the tree on a separate line
 --
@@ -58,5 +59,3 @@ exampleTwo = levelOrderTraversal [("1")
                                  [("2") [("4") [("8") t t] [("9") t t]] 
                                         [("6") [("10") t t] [("12") t t]]] 
                                  [("3") [("5") [("11") t t] t] [("7") t t]]]
-
-exampleTwo

demos/size.tri

@@ -1,3 +1,5 @@
+main = size size
+
 compose = \f g x : f (g x)
 
 succ = y (\self :
@@ -17,5 +19,3 @@ size = (\x :
         self
         (\x y : compose (self x) (self y))
         x)) x 0))
-
-size size

demos/toSource.tri

@@ -1,3 +1,4 @@
+main = toSource not?
 -- Thanks to intensionality, we can inspect the structure of a given value
 -- even if it's a function. This includes lambdas which are eliminated to
 -- Tree Calculus (TC) terms during evaluation.