Adding examples to Janet api documentation.

examples/++.janet

@@ -0,0 +1,3 @@
+(var a 0) # -> 0
+(set a (+ a 1)) # -> 1
+(++ a) # -> 2 (same effect as above)

examples/--.janet

@@ -0,0 +1,3 @@
+(var x 10) # -> 10
+(set x (- x 1)) # -> 9
+(-- x) # -> 8 (same effect as above)

examples/-.janet

@@ -1,7 +1,7 @@
 (-) # -> 0
 (- 10) # -> -10
 (- 1 2) # -> -1
-(+ 1.4 -4.5) # -> 5.9
+(- 1.4 -4.5) # -> -5.9
 
 # Equivalent to (- first (+ ;rest))
 (- 1 2 3 4 5 6 7 8 9 10) # -> -53

examples/-_62.janet

@@ -0,0 +1,5 @@
+(-> {:a [1 2 3] :b [4 5 6]}
+    (get :a)
+    (sum)
+    ((fn [x y] (/ x y)) 2)) # The 6 from the sum is threaded first and binds to x, then 2 binds to y.
+# -> 3

examples/accumulate.janet

@@ -0,0 +1,8 @@
+(reduce + 0 [1 2 3 4]) #-> 10
+(accumulate + 0 [1 2 3 4]) # -> @[1 3 6 10]
+
+(reduce + 0 []) # -> 0
+(accumulate + 0 []) # -> @[]
+
+(reduce string "" ["J" "a" "n" "e" "t"]) # -> "Janet"
+(accumulate string "" ["J" "a" "n" "e" "t"]) # -> @["J" "Ja" "Jan" "Jane" "Janet"]

examples/accumulate2.janet

@@ -0,0 +1,8 @@
+(reduce2 + [1 2 3 4]) #-> 10
+(accumulate2 + [1 2 3 4]) # -> @[1 3 6 10]
+
+(reduce2 + []) # -> 0
+(accumulate2 + []) # -> @[]
+
+(reduce2 max [1 4 2 3 9 5]) # -> 9
+(accumulate2 max [1 4 2 3 9 5]) # -> @[1 4 4 4 9 9]

examples/all.janet

@@ -0,0 +1,8 @@
+(all pos? [1 2 3]) #-> true
+(all pos? [1 2 -3]) #-> false
+
+(all pos? []) # -> true
+(all neg? []) # -> true
+
+(all truthy? [1 2 3]) # -> true
+(all truthy? [1 2 nil]) # -> false