queen-attack: predefined errors (#247)

Author: keiravillekode

exercises/practice/queen-attack/.meta/example.factor

@@ -1,13 +1,14 @@
 USING: accessors kernel locals math ;
 IN: queen-attack
 
+ERROR: row-not-on-board ;
+ERROR: column-not-on-board ;
+
 TUPLE: queen row column ;
 
 :: <queen> ( row column -- queen )
-    row 0 < [ "row not positive" throw ] when
-    row 7 > [ "row not on board" throw ] when
-    column 0 < [ "column not positive" throw ] when
-    column 7 > [ "column not on board" throw ] when
+    row 0 < row 7 > or [ row-not-on-board ] when
+    column 0 < column 7 > or [ column-not-on-board ] when
     row column queen boa ;
 
 :: can-attack? ( queen1 queen2 -- ? )

exercises/practice/queen-attack/.meta/generator.jl

@@ -10,8 +10,9 @@ function gen_test_case(case)
         column = Int(pos["column"])
         expected = case["expected"]
         if expected isa AbstractDict
-            msg = expected["error"]
-            return """[ $(row) $(column) <queen> ]\n[ "$(escape_factor(msg))" = ] must-fail-with"""
+            pred = occursin("row", expected["error"]) ?
+                "row-not-on-board?" : "column-not-on-board?"
+            return """[ $(row) $(column) <queen> ]\n[ $(pred) ] must-fail-with"""
         else
             return """[ $(row) $(column) <queen> drop ] must-not-fail"""
         end

exercises/practice/queen-attack/queen-attack/queen-attack-tests.factor

@@ -8,19 +8,19 @@ STOP-HERE
 
 "queen must have positive row" description
 [ -2 2 <queen> ]
-[ "row not positive" = ] must-fail-with
+[ row-not-on-board? ] must-fail-with
 
 "queen must have row on board" description
 [ 8 4 <queen> ]
-[ "row not on board" = ] must-fail-with
+[ row-not-on-board? ] must-fail-with
 
 "queen must have positive column" description
 [ 2 -2 <queen> ]
-[ "column not positive" = ] must-fail-with
+[ column-not-on-board? ] must-fail-with
 
 "queen must have column on board" description
 [ 4 8 <queen> ]
-[ "column not on board" = ] must-fail-with
+[ column-not-on-board? ] must-fail-with
 
 "cannot attack" description
 { f } [ 2 4 <queen> 6 6 <queen> can-attack? ] unit-test

exercises/practice/queen-attack/queen-attack/queen-attack.factor

@@ -1,6 +1,9 @@
 USING: kernel ;
 IN: queen-attack
 
+ERROR: row-not-on-board ;
+ERROR: column-not-on-board ;
+
 : <queen> ( row column -- queen )
     "unimplemented" throw ;