Rework module system

Don't require/allow naming a module, instead require that the importer
names it. Allow importing into the local scope with the name !Local.
Simplify namespacing logic. Updates all tests to reflect these changes.

demos/equality.tri

@@ -1,6 +1,4 @@
-!module Equality
-
-!import "lib/base.tri" Lib
+!import "lib/base.tri" !Local
 
 main = lambdaEqualsTC
 
@@ -28,7 +26,7 @@ not_Lambda? = demo_matchBool demo_false demo_true
 -- to different tree representations even if they share extensional behavior.
 
 -- Let's see if these are the same:
-lambdaEqualsTC = Lib.equal? not_TC? not_Lambda?
+lambdaEqualsTC = equal? not_TC? not_Lambda?
 
 -- Here are some checks to verify their extensional behavior is the same:
 true_TC?  = not_TC? demo_false
@@ -37,5 +35,5 @@ false_TC? = not_TC? demo_true
 true_Lambda?  = not_Lambda? demo_false
 false_Lambda? = not_Lambda? demo_true
 
-bothTrueEqual?  = Lib.equal? true_TC?  true_Lambda?
-bothFalseEqual? = Lib.equal? false_TC? false_Lambda?
+bothTrueEqual?  = equal? true_TC?  true_Lambda?
+bothFalseEqual? = equal? false_TC? false_Lambda?

demos/levelOrderTraversal.tri

@@ -1,6 +1,4 @@
-!module LOT
-
-!import "lib/base.tri" Lib
+!import "lib/base.tri" !Local
 
 main = exampleTwo
 -- Level Order Traversal of a labelled binary tree
@@ -19,41 +17,41 @@ main = exampleTwo
 --    /   /  \
 --   4   5    6
 
-label = \node : Lib.head node
+label = \node : head node
 
-left = (\node : Lib.if (Lib.emptyList? node)
+left = (\node : if (emptyList? node)
   [] 
-  (Lib.if (Lib.emptyList? (Lib.tail node)) 
+  (if (emptyList? (tail node)) 
     [] 
-    (Lib.head (Lib.tail node))))
+    (head (tail node))))
 
-right = (\node : Lib.if (Lib.emptyList? node) 
+right = (\node : if (emptyList? node) 
   [] 
-  (Lib.if (Lib.emptyList? (Lib.tail node)) 
+  (if (emptyList? (tail node)) 
     [] 
-    (Lib.if (Lib.emptyList? (Lib.tail (Lib.tail node))) 
+    (if (emptyList? (tail (tail node))) 
       [] 
-      (Lib.head (Lib.tail (Lib.tail node))))))
+      (head (tail (tail node))))))
 
-processLevel = Lib.y (\self queue : Lib.if (Lib.emptyList? queue) 
+processLevel = y (\self queue : if (emptyList? queue) 
   [] 
-  (Lib.pair (Lib.map label queue) (self (Lib.filter 
-    (\node : Lib.not? (Lib.emptyList? node)) 
-      (Lib.lconcat (Lib.map left queue) (Lib.map right queue))))))
+  (pair (map label queue) (self (filter 
+    (\node : not? (emptyList? node)) 
+      (lconcat (map left queue) (map right queue))))))
 
 levelOrderTraversal_ = \a : processLevel (t a t)
 
-toLineString = Lib.y (\self levels : Lib.if (Lib.emptyList? levels) 
+toLineString = y (\self levels : if (emptyList? levels) 
   "" 
-  (Lib.lconcat 
-    (Lib.lconcat (Lib.map (\x : Lib.lconcat x " ") (Lib.head levels)) "") 
-    (Lib.if (Lib.emptyList? (Lib.tail levels)) "" (Lib.lconcat (t (t 10 t) t) (self (Lib.tail levels))))))
+  (lconcat 
+    (lconcat (map (\x : lconcat x " ") (head levels)) "") 
+    (if (emptyList? (tail levels)) "" (lconcat (t (t 10 t) t) (self (tail levels))))))
 
 levelOrderToString = \s : toLineString (levelOrderTraversal_ s)
 
-flatten = Lib.foldl (\acc x : Lib.lconcat acc x) ""
+flatten = foldl (\acc x : lconcat acc x) ""
 
-levelOrderTraversal = \s : Lib.lconcat (t 10 t) (flatten (levelOrderToString s))
+levelOrderTraversal = \s : lconcat (t 10 t) (flatten (levelOrderToString s))
 
 exampleOne = levelOrderTraversal [("1") 
                                  [("2") [("4") t t] t] 

demos/size.tri

@@ -1,24 +1,22 @@
-!module Size
-
-!import "lib/base.tri" Lib
+!import "lib/base.tri" !Local
 
 main = size size
 
 compose = \f g x : f (g x)
 
-succ = Lib.y (\self :
-  Lib.triage
+succ = y (\self :
+  triage
     1
     t
-    (Lib.triage
+    (triage
       (t (t t))
-      (\_ Lib.tail : t t (self Lib.tail))
+      (\_ tail : t t (self tail))
       t))
 
 size = (\x :
-  (Lib.y (\self x :
+  (y (\self x :
     compose succ
-      (Lib.triage
+      (triage
         (\x : x)
         self
         (\x y : compose (self x) (self y))

demos/toSource.tri

@@ -1,8 +1,6 @@
-!module ToSource
+!import "lib/base.tri" !Local
 
-!import "lib/base.tri" Lib
-
-main = toSource Lib.not?
+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.
@@ -16,29 +14,29 @@ main = toSource Lib.not?
 -- triage = (\leaf stem fork : t (t leaf stem) fork)
 
 -- Base case of a single Leaf
-sourceLeaf = t (Lib.head "t")
+sourceLeaf = t (head "t")
 
 -- Stem case
 sourceStem = (\convert : (\a rest :
-  t (Lib.head "(")                       -- Start with a left parenthesis "(".
-    (t (Lib.head "t")                    -- Add a "t"
-      (t (Lib.head " ")                  -- Add a space.
-        (convert a                       -- Recursively convert the argument.
-          (t (Lib.head ")") rest))))))   -- Close with ")" and append the rest.
+  t (head "(")                       -- Start with a left parenthesis "(".
+    (t (head "t")                    -- Add a "t"
+      (t (head " ")                  -- Add a space.
+        (convert a                   -- Recursively convert the argument.
+          (t (head ")") rest))))))   -- Close with ")" and append the rest.
 
 -- Fork case
 sourceFork = (\convert : (\a b rest :
-  t (Lib.head "(")                           -- Start with a left parenthesis "(".
-    (t (Lib.head "t")                        -- Add a "t"
-      (t (Lib.head " ")                      -- Add a space.
-        (convert a                           -- Recursively convert the first arg.
-          (t (Lib.head " ")                  -- Add another space.
-            (convert b                       -- Recursively convert the second arg.
-              (t (Lib.head ")") rest)))))))) -- Close with ")" and append the rest.
+  t (head "(")                           -- Start with a left parenthesis "(".
+    (t (head "t")                        -- Add a "t"
+      (t (head " ")                      -- Add a space.
+        (convert a                       -- Recursively convert the first arg.
+          (t (head " ")                  -- Add another space.
+            (convert b                   -- Recursively convert the second arg.
+              (t (head ")") rest)))))))) -- Close with ")" and append the rest.
 
 -- Wrapper around triage 
-toSource_ = Lib.y (\self arg :
-  Lib.triage
+toSource_ = y (\self arg :
+  triage
     sourceLeaf        -- `triage` "a" case, Leaf
     (sourceStem self) -- `triage` "b" case, Stem
     (sourceFork self) -- `triage` "c" case, Fork
@@ -47,5 +45,5 @@ toSource_ = Lib.y (\self arg :
 -- toSource takes a single TC term and returns a String
 toSource = \v : toSource_ v ""
 
-exampleOne = toSource Lib.true -- OUT: "(t t)"
-exampleTwo = toSource Lib.not? -- OUT: "(t (t (t t) (t t t)) (t t (t t t)))"
+exampleOne = toSource true -- OUT: "(t t)"
+exampleTwo = toSource not? -- OUT: "(t (t (t t) (t t t)) (t t (t t t)))"