Support !!foo as a double-negation

compiler/frontend/src/org/jetbrains/jet/lang/parsing/JetExpressionParsing.java

@@ -64,7 +64,9 @@ public class JetExpressionParsing extends AbstractJetParsing {
 
     /*package*/ static final TokenSet EXPRESSION_FIRST = TokenSet.create(
             // Prefix
-            MINUS, PLUS, MINUSMINUS, PLUSPLUS, EXCL, LBRACKET, LABEL_IDENTIFIER, AT, ATAT,
+            MINUS, PLUS, MINUSMINUS, PLUSPLUS,
+            EXCL, EXCLEXCL, // Joining complex tokens makes it necessary to put EXCLEXCL here
+            LBRACKET, LABEL_IDENTIFIER, AT, ATAT,
             // Atomic
 
             LPAR, // parenthesized
@@ -325,24 +327,34 @@ public class JetExpressionParsing extends AbstractJetParsing {
      */
     private void parsePrefixExpression() {
 //        System.out.println("pre at "  + myBuilder.getTokenText());
+
         if (at(LBRACKET)) {
             if (!parseLocalDeclaration()) {
                 PsiBuilder.Marker expression = mark();
                 myJetParsing.parseAnnotations(false);
                 parsePrefixExpression();
                 expression.done(ANNOTATED_EXPRESSION);
-            } else {
+            }
+            else {
                 return;
             }
-        } else if (atSet(Precedence.PREFIX.getOperations())) {
+        }
-            PsiBuilder.Marker expression = mark();
+        else {
+            myBuilder.disableJoiningComplexTokens();
+            if (atSet(Precedence.PREFIX.getOperations())) {
+                PsiBuilder.Marker expression = mark();
 
-            parseOperationReference();
+                parseOperationReference();
 
-            parsePrefixExpression();
+                myBuilder.restoreJoiningComplexTokensState();
-            expression.done(PREFIX_EXPRESSION);
+
-        } else {
+                parsePrefixExpression();
-            parsePostfixExpression();
+                expression.done(PREFIX_EXPRESSION);
+            }
+            else {
+                myBuilder.restoreJoiningComplexTokensState();
+                parsePostfixExpression();
+            }
         }
     }
 

compiler/frontend/src/org/jetbrains/jet/lang/parsing/SemanticWhitespaceAwarePsiBuilderImpl.java

@@ -32,7 +32,7 @@ import static org.jetbrains.jet.lexer.JetTokens.*;
  * @author abreslav
  */
 public class SemanticWhitespaceAwarePsiBuilderImpl extends PsiBuilderAdapter implements SemanticWhitespaceAwarePsiBuilder {
-    private final TokenSet complexTokens = TokenSet.create(SAFE_ACCESS, ELVIS);
+    private final TokenSet complexTokens = TokenSet.create(SAFE_ACCESS, ELVIS, EXCLEXCL);
     private final Stack<Boolean> joinComplexTokens = new Stack<Boolean>();
 
     private final Stack<Boolean> newlinesEnabled = new Stack<Boolean>();
@@ -126,6 +126,10 @@ public class SemanticWhitespaceAwarePsiBuilderImpl extends PsiBuilderAdapter imp
             if (nextRawToken == DOT) return SAFE_ACCESS;
             if (nextRawToken == COLON) return ELVIS;
         }
+        else if (rawTokenType == EXCL) {
+            IElementType nextRawToken = rawLookup(rawLookupSteps);
+            if (nextRawToken == EXCL) return EXCLEXCL;
+        }
         return rawTokenType;
     }
 

compiler/frontend/src/org/jetbrains/jet/lexer/Jet.flex

@@ -270,7 +270,7 @@ LONG_TEMPLATE_ENTRY_END=\}
 ">="         { return JetTokens.GTEQ      ; }
 "=="         { return JetTokens.EQEQ      ; }
 "!="         { return JetTokens.EXCLEQ    ; }
-"!!"         { return JetTokens.EXCLEXCL  ; }
+//"!!"         { return JetTokens.EXCLEXCL  ; }
 "&&"         { return JetTokens.ANDAND    ; }
 "||"         { return JetTokens.OROR      ; }
 //"?."         { return JetTokens.SAFE_ACCESS;}

compiler/testData/psi/AssertNotNull.jet

@@ -0,0 +1,10 @@
+fun main(args : Array<String>) {
+    !true;
+    !!true;
+    !!!true;
+    !!!!true;
+    true!!!
+    true!!!!
+    true!!and(false)
+    true!!.and(false)
+}

compiler/testData/psi/AssertNotNull.txt

@@ -0,0 +1,126 @@
+JetFile: AssertNotNull.jet
+  NAMESPACE_HEADER
+    <empty list>
+  FUN
+    PsiElement(fun)('fun')
+    PsiWhiteSpace(' ')
+    PsiElement(IDENTIFIER)('main')
+    VALUE_PARAMETER_LIST
+      PsiElement(LPAR)('(')
+      VALUE_PARAMETER
+        PsiElement(IDENTIFIER)('args')
+        PsiWhiteSpace(' ')
+        PsiElement(COLON)(':')
+        PsiWhiteSpace(' ')
+        TYPE_REFERENCE
+          USER_TYPE
+            REFERENCE_EXPRESSION
+              PsiElement(IDENTIFIER)('Array')
+            TYPE_ARGUMENT_LIST
+              PsiElement(LT)('<')
+              TYPE_PROJECTION
+                TYPE_REFERENCE
+                  USER_TYPE
+                    REFERENCE_EXPRESSION
+                      PsiElement(IDENTIFIER)('String')
+              PsiElement(GT)('>')
+      PsiElement(RPAR)(')')
+    PsiWhiteSpace(' ')
+    BLOCK
+      PsiElement(LBRACE)('{')
+      PsiWhiteSpace('\n    ')
+      PREFIX_EXPRESSION
+        OPERATION_REFERENCE
+          PsiElement(EXCL)('!')
+        BOOLEAN_CONSTANT
+          PsiElement(true)('true')
+      PsiElement(SEMICOLON)(';')
+      PsiWhiteSpace('\n    ')
+      PREFIX_EXPRESSION
+        OPERATION_REFERENCE
+          PsiElement(EXCL)('!')
+        PREFIX_EXPRESSION
+          OPERATION_REFERENCE
+            PsiElement(EXCL)('!')
+          BOOLEAN_CONSTANT
+            PsiElement(true)('true')
+      PsiElement(SEMICOLON)(';')
+      PsiWhiteSpace('\n    ')
+      PREFIX_EXPRESSION
+        OPERATION_REFERENCE
+          PsiElement(EXCL)('!')
+        PREFIX_EXPRESSION
+          OPERATION_REFERENCE
+            PsiElement(EXCL)('!')
+          PREFIX_EXPRESSION
+            OPERATION_REFERENCE
+              PsiElement(EXCL)('!')
+            BOOLEAN_CONSTANT
+              PsiElement(true)('true')
+      PsiElement(SEMICOLON)(';')
+      PsiWhiteSpace('\n    ')
+      PREFIX_EXPRESSION
+        OPERATION_REFERENCE
+          PsiElement(EXCL)('!')
+        PREFIX_EXPRESSION
+          OPERATION_REFERENCE
+            PsiElement(EXCL)('!')
+          PREFIX_EXPRESSION
+            OPERATION_REFERENCE
+              PsiElement(EXCL)('!')
+            PREFIX_EXPRESSION
+              OPERATION_REFERENCE
+                PsiElement(EXCL)('!')
+              BOOLEAN_CONSTANT
+                PsiElement(true)('true')
+      PsiElement(SEMICOLON)(';')
+      PsiWhiteSpace('\n    ')
+      POSTFIX_EXPRESSION
+        BOOLEAN_CONSTANT
+          PsiElement(true)('true')
+        OPERATION_REFERENCE
+          PsiElement(EXCLEXCL)('!!')
+      PsiErrorElement:Unexpected tokens (use ';' to separate expressions on the same line)
+        PsiElement(EXCL)('!')
+      PsiWhiteSpace('\n    ')
+      POSTFIX_EXPRESSION
+        POSTFIX_EXPRESSION
+          BOOLEAN_CONSTANT
+            PsiElement(true)('true')
+          OPERATION_REFERENCE
+            PsiElement(EXCLEXCL)('!!')
+        OPERATION_REFERENCE
+          PsiElement(EXCLEXCL)('!!')
+      PsiWhiteSpace('\n    ')
+      BINARY_EXPRESSION
+        POSTFIX_EXPRESSION
+          BOOLEAN_CONSTANT
+            PsiElement(true)('true')
+          OPERATION_REFERENCE
+            PsiElement(EXCLEXCL)('!!')
+        OPERATION_REFERENCE
+          PsiElement(IDENTIFIER)('and')
+        PARENTHESIZED
+          PsiElement(LPAR)('(')
+          BOOLEAN_CONSTANT
+            PsiElement(false)('false')
+          PsiElement(RPAR)(')')
+      PsiWhiteSpace('\n    ')
+      DOT_QUALIFIED_EXPRESSION
+        POSTFIX_EXPRESSION
+          BOOLEAN_CONSTANT
+            PsiElement(true)('true')
+          OPERATION_REFERENCE
+            PsiElement(EXCLEXCL)('!!')
+        PsiElement(DOT)('.')
+        CALL_EXPRESSION
+          REFERENCE_EXPRESSION
+            PsiElement(IDENTIFIER)('and')
+          VALUE_ARGUMENT_LIST
+            PsiElement(LPAR)('(')
+            VALUE_ARGUMENT
+              BOOLEAN_CONSTANT
+                PsiElement(false)('false')
+            PsiElement(RPAR)(')')
+      PsiWhiteSpace('\n')
+      PsiElement(RBRACE)('}')