Merge pull request swiftlang#125 from dabelknap/switch-case-where

Support value binding for switch cases

Author: allevato

Sources/PrettyPrint/TokenStreamCreator.swift

@@ -368,6 +368,17 @@ private final class TokenStreamCreator: SyntaxVisitor {
     super.visit(node)
   }
 
+  override func visit(_ node: CaseItemSyntax) {
+    before(node.firstToken, tokens: .open)
+    before(node.whereClause?.firstToken, tokens: .break)
+    if let trailingComma = node.trailingComma {
+      after(trailingComma, tokens: .close, .break)
+    } else {
+      after(node.lastToken, tokens: .close)
+    }
+    super.visit(node)
+  }
+
   override func visit(_ node: SwitchDefaultLabelSyntax) {
     // Implementation not needed.
     super.visit(node)
@@ -442,10 +453,6 @@ private final class TokenStreamCreator: SyntaxVisitor {
     super.visit(node)
   }
 
-  override func visit(_ node: CaseItemSyntax) {
-    super.visit(node)
-  }
-
   override func visit(_ node: TypeExprSyntax) {
     super.visit(node)
   }
@@ -943,6 +950,7 @@ private final class TokenStreamCreator: SyntaxVisitor {
   }
 
   override func visit(_ node: ValueBindingPatternSyntax) {
+    after(node.letOrVarKeyword, tokens: .break)
     super.visit(node)
   }
 

Tests/PrettyPrinterTests/SwitchStmtTests.swift

@@ -75,6 +75,40 @@ public class SwitchStmtTests: PrettyPrintTestCase {
     assertPrettyPrintEqual(input: input, expected: expected, linelength: 35)
   }
 
+  public func testSwitchCompoundCases() {
+    let input =
+      """
+      switch someChar {
+      case "a":
+        print("a")
+      case "b", "c":
+        print("bc")
+      case "d", "e", "f", "g", "h":
+        print("defgh")
+      default:
+        print("default")
+      }
+      """
+
+    let expected =
+      """
+      switch someChar {
+      case "a":
+        print("a")
+      case "b", "c":
+        print("bc")
+      case "d", "e", "f",
+           "g", "h":
+        print("defgh")
+      default:
+        print("default")
+      }
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 20)
+  }
+
   public func testNestedSwitch() {
     let input =
       """
@@ -109,4 +143,81 @@ public class SwitchStmtTests: PrettyPrintTestCase {
 
     assertPrettyPrintEqual(input: input, expected: expected, linelength: 35)
   }
+
+  public func testSwitchValueBinding() {
+    let input =
+      """
+      switch someValue {
+      case let thisval:
+        let c = 123
+        var d = 456 + thisval
+      }
+      switch somePoint {
+      case (let x, 0):
+        print(x)
+      case (0, let y):
+        print(y)
+      case let (x, y):
+        print(x + y)
+      }
+      switch anotherPoint {
+      case (let distance, 0), (0, let distance):
+        print(distance)
+      case (let distance, 0), (0, let distance), (let distance, 10):
+        print(distance)
+      default:
+        print("A message")
+      }
+      switch pointy {
+      case let (x, y) where x == y:
+        print("Equal")
+      case let (x, y) where x == -y:
+        print("Opposite sign")
+      case let (reallyLongName, anotherLongName) where reallyLongName == -anotherLongName:
+        print("Opposite sign")
+      case let (x, y):
+        print("Arbitrary value")
+      }
+      """
+
+    let expected =
+      """
+      switch someValue {
+      case let thisval:
+        let c = 123
+        var d = 456 + thisval
+      }
+      switch somePoint {
+      case (let x, 0):
+        print(x)
+      case (0, let y):
+        print(y)
+      case let (x, y):
+        print(x + y)
+      }
+      switch anotherPoint {
+      case (let distance, 0), (0, let distance):
+        print(distance)
+      case (let distance, 0), (0, let distance),
+           (let distance, 10):
+        print(distance)
+      default:
+        print("A message")
+      }
+      switch pointy {
+      case let (x, y) where x == y:
+        print("Equal")
+      case let (x, y) where x == -y:
+        print("Opposite sign")
+      case let (reallyLongName, anotherLongName)
+           where reallyLongName == -anotherLongName:
+        print("Opposite sign")
+      case let (x, y):
+        print("Arbitrary value")
+      }
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 45)
+  }
 }