Updates to demos

demos/equality.tri

@@ -12,19 +12,16 @@ not_TC?     = t (t (t t) (t t t)) (t t (t t t))
 
 -- /demos/toSource.tri contains an explanation of `triage`
 demo_triage = a b c : t (t a b) c
-demo_matchBool = (ot of : demo_triage
-  of
-  (_ : ot)
-  (_ _ : ot)
-)
+demo_matchBool = a b : demo_triage b (_ : a) (_ _ : a)
+
 -- Lambda representation of the Boolean `not` function
 not_Lambda? = demo_matchBool demo_false demo_true
 
--- Since tricu eliminates Lambda terms to SKI combinators, the tree form of many
+-- As tricu eliminates Lambda terms to SKI combinators, the tree form of many
 -- functions defined via Lambda terms are larger than the most efficient TC
--- representation. Between different languages that evaluate to tree calculus 
--- terms, the exact implementation of Lambda elimination may differ and lead 
--- to different tree representations even if they share extensional behavior.
+-- representation possible. Between different languages that evaluate to tree
+-- calculus terms, the exact implementation of Lambda elimination may differ
+-- and lead to different trees even if they share extensional behavior.
 
 -- Let's see if these are the same:
 lambdaEqualsTC = equal? not_TC? not_Lambda?

demos/levelOrderTraversal.tri

@@ -20,13 +20,13 @@ main = exampleTwo
 
 label = node : head node
 
-left = (node : if (emptyList? node)
+left = node : (if (emptyList? node)
   []
   (if (emptyList? (tail node))
     []
     (head (tail node))))
 
-right = (node : if (emptyList? node)
+right = node : (if (emptyList? node)
   []
   (if (emptyList? (tail node))
     []

demos/patternMatching.tri

@@ -0,0 +1,37 @@
+!import "../lib/patterns.tri" !Local
+
+-- We can do conditional pattern matching by providing a list of lists, where
+-- each sublist contains a boolean expression and a function to return if said
+-- boolean expression evaluates to true.
+
+value = 42
+main  = match value [[(equal? "Hello") (_ : ", world!")] [(equal? 42) (_ : "The answer.")]]
+
+-- < main
+-- > "The answer."
+
+matchExample = (x : match x
+  [[(equal? 1)  (_ : "one")]
+   [(equal? 2)  (_ : "two")]
+   [(equal? 3)  (_ : "three")]
+   [(equal? 4)  (_ : "four")]
+   [(equal? 5)  (_ : "five")]
+   [(equal? 6)  (_ : "six")]
+   [(equal? 7)  (_ : "seven")]
+   [(equal? 8)  (_ : "eight")]
+   [(equal? 9)  (_ : "nine")]
+   [(equal? 10) (_ : "ten")]
+   [ otherwise  (_ : "I ran out of fingers!")]])
+
+-- < matchExample 3
+-- > "three"
+-- < matchExample 5
+-- > "five"
+-- < matchExample 9
+-- > "nine"
+-- < matchExample 11
+-- > "I ran out of fingers!"
+-- < matchExample "three"
+-- > "I ran out of fingers!"
+-- < matchExample [("hello") ("world")]
+-- > "I ran out of fingers!"

demos/size.tri

@@ -3,11 +3,9 @@
 
 main = size size
 
-size = (x :
-  (y (self x :
-    compose succ
-      (triage
-        (x : x)
+size = x : y (self x : compose succ (triage
+  id
   self
   (x y : compose (self x) (self y))
-        x)) x 0))
+  x)
+) x 0

demos/toSource.tri

@@ -18,22 +18,22 @@ main = toSource not?
 sourceLeaf = t (head "t")
 
 -- Stem case
-sourceStem = (convert : (a rest :
+sourceStem = convert : (a 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.
+          (t (head ")") rest)))))   -- Close with ")" and append the rest.
 
 -- Fork case
-sourceFork = (convert : (a b rest :
+sourceFork = convert : (a b 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.
+              (t (head ")") rest))))))) -- Close with ")" and append the rest.
 
 -- Wrapper around triage 
 toSource_ = y (self arg :

lib/list.tri

@@ -1,5 +1,7 @@
 !import "base.tri" !Local
 
+_ = t
+
 matchList = a b : triage a _ b
 
 emptyList? = matchList true (_ _ : false)

lib/patterns.tri

@@ -1,4 +1,5 @@
-!import "list.tri" !Local
+!import "base.tri" !Local
+!import "list.tri" List
 
 match_ = y (self value patterns :
   triage
@@ -16,21 +17,8 @@ match_ = y (self value patterns :
     patterns)
 
 match = (value patterns :
-  match_ value (map (sublist :
-    pair (head sublist) (head (tail sublist)))
+  match_ value (List.map (sublist :
+    pair (List.head sublist) (List.head (List.tail sublist)))
     patterns))
 
 otherwise = const (t t)
-
-matchExample = (x : match x
-  [[(equal? 1) (_ : "one")]
-  [(equal? 2)  (_ : "two")]
-  [(equal? 3)  (_ : "three")]
-  [(equal? 4)  (_ : "four")]
-  [(equal? 5)  (_ : "five")]
-  [(equal? 6)  (_ : "six")]
-  [(equal? 7)  (_ : "seven")]
-  [(equal? 8)  (_ : "eight")]
-  [(equal? 9)  (_ : "nine")]
-  [(equal? 10) (_ : "ten")]
-  [ otherwise  (_ : "I ran out of fingers!")]])