case/when/else

src/Data/Syntax/Statement.hs

@@ -24,14 +24,14 @@ instance Show1 Else where liftShowsPrec = genericLiftShowsPrec
 -- TODO: Alternative definition would flatten if/else if/else chains: data If a = If ![(a, a)] !(Maybe a)
 
 -- | A pattern-matching or computed jump control-flow statement, like 'switch' in C or JavaScript, or 'case' in Ruby or Haskell.
-data Match with a = Match { matchSubject :: !a, matchPatterns :: ![with a] }
+data Match a = Match { matchSubject :: !a, matchPatterns :: !a }
   deriving (Eq, Foldable, Functor, GAlign, Generic1, Show, Traversable)
 
-instance Eq1 with => Eq1 (Match with) where liftEq = genericLiftEq
-instance Show1 with => Show1 (Match with) where liftShowsPrec = genericLiftShowsPrec
+instance Eq1 Match where liftEq = genericLiftEq
+instance Show1 Match where liftShowsPrec = genericLiftShowsPrec
 
 -- | A pattern in a pattern-matching or computed jump control-flow statement, like 'case' in C or JavaScript, 'when' in Ruby, or the left-hand side of '->' in the body of Haskell 'case' expressions.
-newtype Pattern a = Pattern a
+data Pattern a = Pattern { pattern :: !a, patternBody :: !a }
   deriving (Eq, Foldable, Functor, GAlign, Generic1, Show, Traversable)
 
 instance Eq1 Pattern where liftEq = genericLiftEq

src/Language/Ruby/Syntax.hs

@@ -56,6 +56,8 @@ type Syntax = '[
   , Statement.Finally
   , Statement.ForEach
   , Statement.If
+  , Statement.Match
+  , Statement.Pattern
   , Statement.Retry
   , Statement.Return
   , Statement.ScopeEntry
@@ -89,6 +91,7 @@ statement = -- handleError $
   <|> unless
   <|> while'
   <|> until'
+  <|> case'
   <|> emptyStatement
   <|> assignment'
   <|> unary
@@ -255,6 +258,13 @@ until' =
 for :: Assignment
 for = makeTerm <$> symbol For <*> children (Statement.ForEach <$> some identifier <*> statement <*> statements)
 
+case' :: Assignment
+case' = makeTerm <$> symbol Case <*> children (Statement.Match <$> statement <*> when)
+  where
+    when =  makeTerm <$> symbol When <*> children (Statement.Pattern <$> (makeTerm <$> location <*> some pattern) <*> (when <|> else' <|> statements))
+    else' = makeTerm <$> symbol Else <*> children (many statement)
+    pattern = symbol Pattern *> children ((symbol SplatArgument *> children statement) <|> statement)
+
 subscript :: Assignment
 subscript = makeTerm <$> symbol ElementReference <*> children (Expression.Subscript <$> statement <*> many argument)
 

test/fixtures/ruby/when-else.A.rb

@@ -1,5 +1,6 @@
 case foo
-when bar
+when qux
+when bar, *a
   baz
 else
 end

test/fixtures/ruby/when-else.diff+A.txt

@@ -4,5 +4,11 @@
     (When
       (Args
         (Identifier))
-      (Identifier)
-      (Else))))+}
+      (When
+        (Args
+          (Identifier))
+        (Args
+          (Other "splat_argument"
+            (Identifier)))
+        (Identifier)
+        (Else)))))+}

test/fixtures/ruby/when-else.diff-A.txt

@@ -4,5 +4,11 @@
     (When
       (Args
         (Identifier))
-      (Identifier)
-      (Else))))-}
+      (When
+        (Args
+          (Identifier))
+        (Args
+          (Other "splat_argument"
+            (Identifier)))
+        (Identifier)
+        (Else)))))-}

test/fixtures/ruby/when-else.diffA-B.txt

@@ -3,8 +3,16 @@
     (Identifier)
     (When
       (Args
-        (Identifier))
-      (Identifier)
-    { (Else)
-    ->(Else
-        (Identifier)) })))
+      { (Identifier)
+      ->(Identifier) })
+    { (When
+        (Args
+          (Identifier))
+        (Args
+          (Other "splat_argument"
+            (Identifier)))
+        (Identifier)
+        (Else))
+    ->(Identifier) }
+    {+(Else
+        (Identifier))+})))

test/fixtures/ruby/when-else.diffB-A.txt

@@ -3,8 +3,16 @@
     (Identifier)
     (When
       (Args
-        (Identifier))
-      (Identifier)
-    { (Else
-        (Identifier))
-    ->(Else) })))
+      { (Identifier)
+      ->(Identifier) })
+    { (Identifier)
+    ->(When
+        (Args
+          (Identifier))
+        (Args
+          (Other "splat_argument"
+            (Identifier)))
+        (Identifier)
+        (Else)) }
+    {-(Else
+        (Identifier))-})))

test/fixtures/ruby/when-else.parseA.txt

@@ -4,5 +4,11 @@
     (When
       (Args
         (Identifier))
-      (Identifier)
-      (Else))))
+      (When
+        (Args
+          (Identifier))
+        (Args
+          (Other "splat_argument"
+            (Identifier)))
+        (Identifier)
+        (Else)))))