Field references ($fieldName) and quoted literal (anyWord)

idea/src/org/jetbrains/jet/JetNodeTypes.java

@@ -110,6 +110,7 @@ public interface JetNodeTypes {
     JetNodeType TUPLE_PATTERN                       = new JetNodeType("TUPLE_PATTERN");
     JetNodeType OBJECT_LITERAL                      = new JetNodeType("OBJECT_LITERAL");
     JetNodeType ROOT_NAMESPACE                      = new JetNodeType("ROOT_NAMESPACE");
+    JetNodeType FIELD_REFERENCE                     = new JetNodeType("FIELD_REFERENCE");
 
     IElementType NAMESPACE_NAME = new JetNodeType("NAMESPACE_NAME");
 }

idea/src/org/jetbrains/jet/lang/JetHighlighter.java

@@ -31,6 +31,12 @@ public class JetHighlighter extends SyntaxHighlighterBase {
                                                   SyntaxHighlighterColors.KEYWORD.getDefaultAttributes()
                                                  );
 
+    public static final TextAttributesKey JET_FIELD_IDENTIFIER = TextAttributesKey.createTextAttributesKey(
+                                                  "JET.FIELD.IDENTIFIER",
+// TODO: proper attributes
+                                                  SyntaxHighlighterColors.KEYWORD.getDefaultAttributes()
+                                                 );
+
     private static final TextAttributesKey JET_NUMBER = TextAttributesKey.createTextAttributesKey(
                                                  "JET.NUMBER",
                                                  SyntaxHighlighterColors.NUMBER.getDefaultAttributes()
@@ -68,6 +74,7 @@ public class JetHighlighter extends SyntaxHighlighterBase {
 
         fillMap(keys1, JetTokens.KEYWORDS, JET_KEYWORD);
 
+        keys1.put(JetTokens.FIELD_IDENTIFIER, JET_FIELD_IDENTIFIER);
         keys1.put(JetTokens.INTEGER_LITERAL, JET_NUMBER);
         keys1.put(JetTokens.LONG_LITERAL, JET_NUMBER);
         keys1.put(JetTokens.FLOAT_LITERAL, JET_NUMBER);

idea/src/org/jetbrains/jet/lang/parsing/JetExpressionParsing.java

@@ -324,6 +324,9 @@ public class JetExpressionParsing extends AbstractJetParsing {
                 VAR_KEYWORD, TYPE_KEYWORD, DECOMPOSER_KEYWORD)) {
             parseLocalDeclaration();
         }
+        else if (at(FIELD_IDENTIFIER)) {
+            parseOneTokenExpression(FIELD_REFERENCE);
+        }
         else if (at(IDENTIFIER)) {
             if (JetParsing.MODIFIER_KEYWORD_MAP.containsKey(myBuilder.getTokenText())) {
                 if (!parseLocalDeclaration()) {
@@ -337,7 +340,7 @@ public class JetExpressionParsing extends AbstractJetParsing {
             parseFunctionLiteral();
         }
         else if (!parseLiteralConstant()) {
-            // TODO: betters recovery if FIRST(expression) did not match
+            // TODO: better recovery if FIRST(expression) did not match
             errorAndAdvance("Expecting an expression");
         }
     }

idea/src/org/jetbrains/jet/lexer/Jet.flex

@@ -21,7 +21,12 @@ DIGIT=[0-9]
 HEX_DIGIT=[0-9A-Fa-f]
 WHITE_SPACE_CHAR=[\ \n\t\f]
 
-IDENTIFIER=[:jletter:] [:jletterdigit:]*
+// TODO: prohibit '$' in identifiers?
+PLAIN_IDENTIFIER=[:jletter:] [:jletterdigit:]*
+// TODO: this one MUST allow everything accepted by the runtime
+ESCAPED_IDENTIFIER = `{PLAIN_IDENTIFIER}`
+IDENTIFIER = {PLAIN_IDENTIFIER}|{ESCAPED_IDENTIFIER}
+FIELD_IDENTIFIER = \${IDENTIFIER}
 
 BLOCK_COMMENT=("/*"[^"*"]{COMMENT_TAIL})|"/*"
 DOC_COMMENT="/*""*"+("/"|([^"/""*"]{COMMENT_TAIL}))?
@@ -111,6 +116,7 @@ RAW_STRING_LITERAL = {THREE_QUO} {QUO_STRING_CHAR}* {THREE_QUO}?
 <YYINITIAL> "do"         { return JetTokens.DO_KEYWORD ;}
 <YYINITIAL> "as"         { return JetTokens.AS_KEYWORD ;}
 
+<YYINITIAL> {FIELD_IDENTIFIER} { return JetTokens.FIELD_IDENTIFIER; }
 <YYINITIAL> {IDENTIFIER} { return JetTokens.IDENTIFIER; }
 
 <YYINITIAL> "==="        { return JetTokens.EQEQEQ    ; }

idea/src/org/jetbrains/jet/lexer/JetTokens.java

@@ -58,6 +58,7 @@ public interface JetTokens {
 
 
     JetToken IDENTIFIER = new JetToken("IDENTIFIER");
+    JetToken FIELD_IDENTIFIER = new JetToken("FIELD_IDENTIFIER");
 
     JetToken LBRACKET    = new JetToken("LBRACKET");
     JetToken RBRACKET    = new JetToken("RBRACKET");

idea/testData/psi/QuotedIdentifiers.jet

@@ -0,0 +1,3 @@
+[`return`] fun `namespace`() {
+  `class`()
+}

idea/testData/psi/QuotedIdentifiers.txt

@@ -0,0 +1,30 @@
+JetFile: QuotedIdentifiers.jet
+  NAMESPACE
+    FUN
+      MODIFIER_LIST
+        ATTRIBUTE_ANNOTATION
+          PsiElement(LBRACKET)('[')
+          ATTRIBUTE
+            USER_TYPE
+              PsiElement(IDENTIFIER)('`return`')
+          PsiElement(RBRACKET)(']')
+      PsiWhiteSpace(' ')
+      PsiElement(fun)('fun')
+      PsiWhiteSpace(' ')
+      PsiElement(IDENTIFIER)('`namespace`')
+      TYPE_PARAMETER_LIST
+        <empty list>
+      VALUE_PARAMETER_LIST
+        PsiElement(LPAR)('(')
+        PsiElement(RPAR)(')')
+      PsiWhiteSpace(' ')
+      BLOCK
+        PsiElement(LBRACE)('{')
+        PsiWhiteSpace('\n  ')
+        CALL_EXPRESSION
+          PsiElement(IDENTIFIER)('`class`')
+          VALUE_ARGUMENT_LIST
+            PsiElement(LPAR)('(')
+            PsiElement(RPAR)(')')
+        PsiWhiteSpace('\n')
+        PsiElement(RBRACE)('}')

idea/testData/psi/examples/priorityqueues/BinaryHeap.txt

@@ -927,7 +927,8 @@ JetFile: BinaryHeap.jet
                   PsiElement(LBRACE)('{')
                   PsiWhiteSpace('\n        ')
                   BINARY_EXPRESSION
-                    PsiElement(IDENTIFIER)('$value')
+                    FIELD_REFERENCE
+                      PsiElement(FIELD_IDENTIFIER)('$value')
                     PsiWhiteSpace(' ')
                     PsiElement(EQ)('=')
                     PsiWhiteSpace(' ')