move iota to sequences, fix example, add unit tests, make iota's slot integers only

core/sequences/sequences-docs.factor

@@ -1279,9 +1279,9 @@ HELP: iota
 { $description "Creates an immutable virtual sequence containing the integers from 0 to " { $snippet "n-1" } "." }
 { $examples
   { $example
-    "USING: math.parser sequences ;"
+    "USING: math sequences prettyprint ;"
     "3 iota [ sq ] map ."
-    "{ \"0\" \"1\" \"2\" }"
+    "{ 0 1 4 }"
   }
 } ;
 

core/sequences/sequences-tests.factor

@@ -276,4 +276,8 @@ M: bogus-hashcode hashcode* 2drop 0 >bignum ;
 
 { 3 0 } [ [ 3drop ] 3each ] must-infer-as
 
-[ V{ 0 3 } ] [ "A" { "A" "B" "C" "A" "D" } indices ] unit-test
+[ V{ 0 3 } ] [ "A" { "A" "B" "C" "A" "D" } indices ] unit-test
+
+[ "asdf" iota ] must-fail
+[ T{ iota { n 10 } } ] [ 10 iota ] unit-test
+[ 0 ] [ 10 iota first ] unit-test

core/sequences/sequences.factor

@@ -101,11 +101,15 @@ M: integer nth-unsafe drop ;
 
 INSTANCE: integer immutable-sequence
 
+PRIVATE>
+
 ! In the future, this will replace integer sequences
-TUPLE: iota { n read-only } ;
+TUPLE: iota { n integer read-only } ;
 
 : iota ( n -- iota ) \ iota boa ; inline
 
+<PRIVATE
+
 M: iota length n>> ;
 M: iota nth-unsafe drop ;