Formatter Updates Deprecated Boolean Operator Syntax (#1214)

Author: yjt98765

src/QsFmt/Formatter.Tests/Examples.fs

@@ -368,3 +368,21 @@ let ``Array Syntax Expression Size`` =
         let t2 = [0.0, size = 2+1];
     }
 }"""
+
+[<Example(ExampleKind.Update)>]
+let ``Updates Binary Boolean Operators`` =
+    """namespace Foo {
+    operation Bar() : Unit {
+        let t1 = True &&  False;
+        let t2 = True||False;
+        let t3 = !!True;
+    }
+}""",
+
+    """namespace Foo {
+    operation Bar() : Unit {
+        let t1 = True and  False;
+        let t2 = True or False;
+        let t3 = not not True;
+    }
+}"""

src/QsFmt/Formatter/Formatter.fs

@@ -85,6 +85,7 @@ let versionToUpdateRules (version: Version option) =
                 simpleRule unitUpdate
                 simpleRule forParensUpdate
                 simpleRule arraySyntaxUpdate
+                simpleRule booleanOperatorUpdate
             ]
 
     rules |> List.fold (>>) id

src/QsFmt/Formatter/Rules.fs

@@ -323,3 +323,44 @@ let checkArraySyntax fileName document =
         }
 
     reducer.Document document
+
+/// <summary>
+/// Insert a whitespace to <paramref name="prefix"/> if it is empty.
+/// </summary>
+let ensureSpace prefix =
+    if List.isEmpty prefix then [ spaces 1 ] else prefix
+
+let booleanOperatorUpdate =
+    { new Rewriter<_>() with
+        override _.Expression((), expression) =
+            let dict =
+                Map [ ("!", "not")
+                      ("&&", "and")
+                      ("||", "or") ]
+
+            let updated =
+                match expression with
+                | PrefixOperator prefixOperator when dict |> Map.containsKey prefixOperator.PrefixOperator.Text ->
+                    {
+                        PrefixOperator =
+                            { prefixOperator.PrefixOperator with
+                                Text = dict |> Map.find prefixOperator.PrefixOperator.Text
+                            }
+                        Operand = prefixOperator.Operand |> Expression.mapPrefix ensureSpace
+                    }
+                    |> PrefixOperator
+                | InfixOperator infixOperator when dict |> Map.containsKey infixOperator.InfixOperator.Text ->
+                    {
+                        Left = infixOperator.Left
+                        InfixOperator =
+                            {
+                                Prefix = infixOperator.InfixOperator.Prefix |> ensureSpace
+                                Text = dict |> Map.find infixOperator.InfixOperator.Text
+                            }
+                        Right = infixOperator.Right |> Expression.mapPrefix ensureSpace
+                    }
+                    |> InfixOperator
+                | _ -> expression
+
+            base.Expression((), updated)
+    }

src/QsFmt/Formatter/Rules.fsi

@@ -34,3 +34,6 @@ val arraySyntaxUpdate: unit Rewriter
 
 /// Provides warnings for deprecated array syntax still in the syntax tree.
 val checkArraySyntax: string -> Document -> string list
+
+/// Replaces `&&`, `||`, and `!` with `and`, `or`, and `not`, respectively.
+val booleanOperatorUpdate : unit Rewriter

src/QsFmt/Parser/QSharpLexer.g4

@@ -90,9 +90,11 @@ Colon : ':';
 Comma : ',';
 DollarQuote : '$"' -> pushMode(INTERPOLATED);
 Dot : '.';
+DoubleAmpersand : '&&';
 DoubleColon : '::';
 DoubleDot : '..';
 DoubleEqual : '==';
+DoublePipe : '||';
 DoubleQuote : '"' -> pushMode(STRING);
 Ellipsis : '...';
 Equal : '=';

src/QsFmt/Parser/QSharpParser.g4

@@ -217,7 +217,7 @@ expression
     | <assoc=right> functor='Controlled' operation=expression # ControlledExpression
     | <assoc=right> functor='Adjoint' operation=expression # AdjointExpression
     | callable=expression openParen='(' (arguments+=expression (commas+=',' arguments+=expression)* commas+=','?)? closeParen=')' # CallExpression
-    | <assoc=right> operator=('-' | 'not' | '~~~') operand=expression # NegationExpression
+    | <assoc=right> operator=('!' | '-' | 'not' | '~~~') operand=expression # NegationExpression
     | <assoc=right> left=expression operator='^' right=expression # ExponentExpression
     | left=expression operator=('*' | '/' | '%') right=expression # MultiplyExpression
     | left=expression operator=('+' | '-') right=expression # AddExpression
@@ -227,8 +227,8 @@ expression
     | left=expression operator='&&&' right=expression # BitwiseAndExpression
     | left=expression operator='^^^' right=expression # BitwiseXorExpression
     | left=expression operator='|||' right=expression # BitwiseOrExpression
-    | left=expression operator='and' right=expression # AndExpression
-    | left=expression operator='or' right=expression # OrExpression
+    | left=expression operator=('&&' | 'and') right=expression # AndExpression
+    | left=expression operator=('||' | 'or') right=expression # OrExpression
     | <assoc=right> cond=expression question='?' ifTrue=expression pipe='|' ifFalse=expression # ConditionalExpression
     | left=expression ellipsis='..' right=expression # RangeExpression
     | left=expression ellipsis='...' # RightOpenRangeExpression