db98abe · elk · git.iko.soy

git.iko.soy/elk

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Improve presentation of incomplete patterns in error messages

db98abeEvan Czaplicki11 years ago

src/Nitpick/Pattern.hs+33−5

compare with master

unifiedsplit

@@ -44,17 +44,28 @@ fromCanonicalPattern (A.A _ pattern) =

45-- TO STRING

47−toString :: Pattern -> String

47+toString :: Bool -> Pattern -> String

48−toString pattern =

48+toString needsParens pattern =

49 case pattern of

50+ Data tag [first,rest] | Var.toString tag == "::" ->

51+ toString (isCons first) first

52+ ++ " :: "

53+ ++ toString False rest

54+

50 Data tag args ->

55 Data tag args ->

56+ if Var.isTuple tag then

57+ "(" ++ List.intercalate ", " (map (toString False) args) ++ ")"

58+

59+ else

60+ addParensIf (needsParens && not (null args)) $

51− List.intercalate " " (Var.toString tag : map toString args)

61+ List.intercalate " " (Var.toString tag : map (toString True) args)

53 Record fields ->

63 Record fields ->

54 "{ " ++ List.intercalate ", " fields ++ " }"

64 "{ " ++ List.intercalate ", " fields ++ " }"

56 Alias alias realPattern ->

66 Alias alias realPattern ->

67+ addParensIf needsParens $

57− toString realPattern ++ " as " ++ alias

68+ toString False realPattern ++ " as " ++ alias

59 Var name ->

70 Var name ->

60 name

71 name

@@ -66,6 +77,23 @@ toString pattern =

66 L.toString literal

77 L.toString literal

68 AnythingBut literalSet ->

79 AnythingBut literalSet ->

69− List.intercalate " " ("<values besides:" : map L.toString (Set.toList literalSet))

80+ List.intercalate " " ("<values besides:" : map L.toString (Set.toList literalSet) ++ [">"])

81+

82+

83+addParensIf :: Bool -> String -> String

84+addParensIf needsParens str =

85+ if needsParens then

86+ "(" ++ str ++ ")"

88+ else

89+ str

90+

91+

92+isCons :: Pattern -> Bool

93+isCons pattern =

94+ case pattern of

95+ Data tag [_,_] ->

96+ Var.toString tag == "::"

98+ _ ->

99+ False

src/Reporting/Error/Pattern.hs+1−1

@@ -48,7 +48,7 @@ viewPatternList unhandledPatterns =

48 splitAt 4 unhandledPatterns

49 in

50 concatMap ((++) "\n ") $

51− map Pattern.toString showPatterns

51+ map (Pattern.toString False) showPatterns

52 ++ if null rest then [] else ["..."]