specify types

config.json

@@ -1621,7 +1621,8 @@
           "recursion",
           "strings",
           "errors",
-          "locals"
+          "locals",
+          "generics"
         ],
         "difficulty": 6
       },

exercises/concept/bering-bearings/.docs/introduction.md

@@ -91,6 +91,17 @@ against its class: a mismatch like `"x" triple` is rejected
 (*expected input value of type integer but got string*) rather
 than silently flowing through.
 
+The output can be annotated the same way. `yes?` types both its
+input and its result:
+
+```factor
+TYPED:: yes? ( word: string -- answer: boolean )
+    word "yes" = ;
+
+"yes" yes? .   ! => t
+"no" yes? .    ! => f
+```
+
 ## Math functions and constants
 
 This exercise also leans on a few words from `math.constants`

exercises/concept/bering-bearings/.meta/exemplar.factor

@@ -1,5 +1,5 @@
 USING: accessors combinators kernel locals math math.constants
-       math.functions namespaces ;
+       math.functions namespaces typed ;
 IN: bering-bearings
 
 SYMBOLS: north east south west
@@ -61,7 +61,7 @@ M: relative flip
         { port      [ starboard ] }
     } case ] change-bearing ;
 
-:: add-bearings ( a b -- x y )
+TYPED:: add-bearings ( a b -- x: number y: number )
     a >cartesian :> ay :> ax
     b >cartesian :> by :> bx
     ax bx +

exercises/concept/bering-bearings/bering-bearings/bering-bearings.factor

@@ -11,4 +11,5 @@ IN: bering-bearings
 ! Define `flip` as a generic word with one method per
 ! direction class.
 
-! Define `add-bearings` here.
+! Define `add-bearings` here, using TYPED:: to type its
+! cartesian outputs: ( a b -- x: number y: number ).

exercises/practice/bank-account/.meta/example.factor

@@ -3,7 +3,7 @@ IN: bank-account
 
 TUPLE: bank-account open? balance lock ;
 
-: <bank-account> ( -- account )
+: <bank-account> ( -- account: bank-account )
     bank-account new
     f >>open?
     0 >>balance

exercises/practice/bank-account/bank-account/bank-account.factor

@@ -1,9 +1,9 @@
-USING: kernel math typed ;
+USING: kernel typed ;
 IN: bank-account
 
 TUPLE: bank-account ;
 
-: <bank-account> ( -- account )
+: <bank-account> ( -- account: bank-account )
     "unimplemented" throw ;
 
 TYPED:: open-account ( account: bank-account -- )

exercises/practice/nth-prime/nth-prime/nth-prime.factor

@@ -1,4 +1,4 @@
-USING: kernel math typed ;
+USING: kernel typed ;
 IN: nth-prime
 
 TYPED:: nth-prime ( n: integer -- prime: integer )

exercises/practice/say/.meta/example.factor

@@ -1,4 +1,4 @@
-USING: kernel locals math math.order sequences strings ;
+USING: kernel locals math math.order sequences strings typed ;
 IN: say
 
 CONSTANT: ones { "zero" "one" "two" "three" "four" "five" "six" "seven" "eight" "nine"
@@ -31,6 +31,6 @@ CONSTANT: tens { f f "twenty" "thirty" "forty" "fifty" "sixty" "seventy" "eighty
     dup 1000 >= [ 1000 "thousand" say-chunk ] when
     dup 0 > [ say-below-1000 swap dup empty? [ drop ] [ swap " " glue ] if ] [ drop ] if ;
 
-: say ( n -- str )
-    dup 0 999999999999 between? [ "input out of range" throw ] unless
-    dup 0 = [ drop "zero" ] [ say-positive ] if ;
+TYPED:: say ( n: integer -- str: string )
+    n 0 999999999999 between? [ "input out of range" throw ] unless
+    n 0 = [ "zero" ] [ n say-positive ] if ;

exercises/practice/say/say/say.factor

@@ -1,5 +1,5 @@
-USING: kernel ;
+USING: kernel typed ;
 IN: say
 
-: say ( n -- str )
+TYPED:: say ( n: integer -- str: string )
     "unimplemented" throw ;