add closures

examples/closures.talc

@@ -0,0 +1,21 @@
+-- adapted from Crafting Interpreters 10.6
+
+make_counter = \-> do
+	var i = 0
+	\-> do
+		i += 1
+		println(i)
+	end
+end
+
+var counter1 = make_counter()
+counter1() -- 1
+counter1() -- 2
+counter1() -- 3
+counter1() -- 4
+var counter2 = make_counter()
+counter2() -- 1
+counter2() -- 2
+counter1() -- 5
+counter1() -- 6
+counter2() -- 3

examples/closures2.talc

@@ -0,0 +1,21 @@
+var i = 0;
+
+var outer = \n -> do
+	var inner = \-> do
+		i = i + n
+	end
+end
+
+var by3 = outer(3)
+var by5 = outer(5)
+
+by3()
+println(i) -- 3
+by3()
+println(i) -- 6
+by5()
+println(i) -- 11
+by5()
+println(i) -- 16
+by3()
+println(i) -- 19

examples/totient.talc

@@ -0,0 +1,7 @@
+totient = \n -> do
+	count(factors(n)) | pairs | map(\v -> do
+		(v!0)^(v!1) - (v!0)^(v!1 - 1)
+	end) | prod
+end
+
+println(totient(6615)) -- 3024