Definition dependency analysis

tricu now allows defining terms in any order and will resolve
dependencies to ensure that they're evaluated in the right order.
Undefined terms are detected and throw errors during dependency
ordering.
For now we can't define top-level mutually recursive terms.

test/Spec.hs

@@ -85,7 +85,7 @@ parser = testGroup "Parser Tests"
 
   , testCase "Parse function definitions" $ do
       let input = "x = (\\a b c : a)"
-          expect = SFunc "x" [] (SLambda ["a"] (SLambda ["b"] (SLambda ["c"] (SVar "a"))))
+          expect = SDef "x" [] (SLambda ["a"] (SLambda ["b"] (SLambda ["c"] (SVar "a"))))
       parseSingle input @?= expect
 
   , testCase "Parse nested Tree Calculus terms" $ do
@@ -105,7 +105,7 @@ parser = testGroup "Parser Tests"
 
   , testCase "Parse function with applications" $ do
       let input  = "f = (\\x : t x)"
-          expect = SFunc "f" [] (SLambda ["x"] (SApp TLeaf (SVar "x")))
+          expect = SDef "f" [] (SLambda ["x"] (SApp TLeaf (SVar "x")))
       parseSingle input @?= expect
 
   , testCase "Parse nested lists" $ do
@@ -147,7 +147,7 @@ parser = testGroup "Parser Tests"
 
   , testCase "Parse nested parentheses in function body" $ do
       let input  = "f = (\\x : t (t (t t)))"
-          expect = SFunc "f" [] (SLambda ["x"] (SApp TLeaf (SApp TLeaf (SApp TLeaf TLeaf))))
+          expect = SDef "f" [] (SLambda ["x"] (SApp TLeaf (SApp TLeaf (SApp TLeaf TLeaf))))
       parseSingle input @?= expect
 
   , testCase "Parse lambda abstractions" $ do
@@ -157,12 +157,12 @@ parser = testGroup "Parser Tests"
 
   , testCase "Parse multiple arguments to lambda abstractions" $ do
       let input  = "x = (\\a b : a)"
-          expect = SFunc "x" [] (SLambda ["a"] (SLambda ["b"] (SVar "a")))
+          expect = SDef "x" [] (SLambda ["a"] (SLambda ["b"] (SVar "a")))
       parseSingle input @?= expect
 
   , testCase "Grouping T terms with parentheses in function application" $ do
       let input  = "x = (\\a : a)\nx (t)"
-          expect = [SFunc "x" [] (SLambda ["a"] (SVar "a")),SApp (SVar "x") TLeaf]
+          expect = [SDef "x" [] (SLambda ["a"] (SVar "a")),SApp (SVar "x") TLeaf]
       parseTricu input @?= expect
 
   , testCase "Comments 1" $ do

test/size.tri

@@ -0,0 +1,21 @@
+compose = \f g x : f (g x)
+
+succ = y (\self :
+  triage
+    1
+    t
+    (triage
+      (t (t t))
+      (\_ tail : t t (self tail))
+      t))
+
+size = (\x :
+  (y (\self x :
+    compose succ
+      (triage
+        (\x : x)
+        self
+        (\x y : compose (self x) (self y))
+        x)) x 0))
+
+size size

test/undefined.tri

@@ -0,0 +1 @@
+namedTerm = undefinedForTesting