Merge pull request #56 from fglock/fix-bop-parser

Fix autoquoting of and/or/xor keywords before =>

Author: fglock

src/main/java/org/perlonjava/parser/ListParser.java

@@ -51,7 +51,7 @@ static ListNode parseZeroOrOneList(Parser parser, int minItems) {
             if (expr.elements.size() > 1) {
                 parser.throwError("syntax error");
             }
-        } else if (token.type == LexerTokenType.EOF || ParserTables.LIST_TERMINATORS.contains(token.text) || token.text.equals(",")) {
+        } else if (token.type == LexerTokenType.EOF || isListTerminator(parser, token) || token.text.equals(",")) {
             // No argument
             expr = new ListNode(parser.tokenIndex);
         } else {
@@ -105,7 +105,7 @@ static ListNode parseZeroOrMoreList(Parser parser, int minItems, boolean wantBlo
                     // Check for infix operators after the regex (like . for concatenation)
                     while (true) {
                         token = TokenUtils.peek(parser);
-                        if (token.type == LexerTokenType.EOF || ParserTables.LIST_TERMINATORS.contains(token.text)) {
+                        if (token.type == LexerTokenType.EOF || isListTerminator(parser, token)) {
                             break;
                         }
                         int tokenPrecedence = parser.getPrecedence(token.text);
@@ -122,7 +122,7 @@ static ListNode parseZeroOrMoreList(Parser parser, int minItems, boolean wantBlo
 
                     expr.elements.add(left);
                     token = TokenUtils.peek(parser);
-                    if (token.type != LexerTokenType.EOF && !ParserTables.LIST_TERMINATORS.contains(token.text)) {
+                    if (token.type != LexerTokenType.EOF && !isListTerminator(parser, token)) {
                         // Consume comma
                         PrototypeArgs.consumeCommaIfPresent(parser, false);
                     }
@@ -175,7 +175,7 @@ static ListNode parseZeroOrMoreList(Parser parser, int minItems, boolean wantBlo
                 TokenUtils.consume(parser);
                 expr.elements.addAll(parseList(parser, ")", 0));
             } else {
-                while (token.type != LexerTokenType.EOF && !ParserTables.LIST_TERMINATORS.contains(token.text)) {
+                while (token.type != LexerTokenType.EOF && !isListTerminator(parser, token)) {
                     // Argument without parentheses
                     expr.elements.add(parser.parseExpression(parser.getPrecedence(",")));
                     token = TokenUtils.peek(parser);
@@ -212,6 +212,31 @@ static LexerToken consumeCommas(Parser parser) {
         return token;
     }
 
+    /**
+     * Checks if a token is a list terminator, with special handling for autoquoting.
+     * Keywords like "and", "or", "xor" should not terminate a list if followed by "=>",
+     * as they should be treated as hash keys in that context.
+     */
+    static boolean isListTerminator(Parser parser, LexerToken token) {
+        if (!ParserTables.LIST_TERMINATORS.contains(token.text)) {
+            return false;
+        }
+        
+        // Special case: and/or/xor before => should be treated as barewords, not terminators
+        if (token.text.equals("and") || token.text.equals("or") || token.text.equals("xor")) {
+            // Look ahead to see if => follows
+            int saveIndex = parser.tokenIndex;
+            TokenUtils.consume(parser); // consume and/or/xor
+            LexerToken nextToken = TokenUtils.peek(parser);
+            parser.tokenIndex = saveIndex; // restore
+            if (nextToken.text.equals("=>")) {
+                return false; // Not a terminator, it's a hash key
+            }
+        }
+        
+        return true;
+    }
+
     /**
      * Parses a generic list with a specified closing delimiter. This method is
      * used for parsing various constructs like parentheses, hash literals, and
@@ -269,8 +294,22 @@ public static boolean looksLikeEmptyList(Parser parser) {
         LexerToken token1 = parser.tokens.get(parser.tokenIndex); // Next token including spaces
         LexerToken nextToken = TokenUtils.peek(parser);  // After spaces
 
-        if (token.type == LexerTokenType.EOF || ParserTables.LIST_TERMINATORS.contains(token.text)
-                || token.text.equals("->")) {
+        // Check if this is a list terminator, but we need to restore position for the check
+        boolean isTerminator = false;
+        if (ParserTables.LIST_TERMINATORS.contains(token.text)) {
+            // Special case: check if and/or/xor followed by =>
+            if (token.text.equals("and") || token.text.equals("or") || token.text.equals("xor")) {
+                if (nextToken.text.equals("=>")) {
+                    isTerminator = false; // Not a terminator, it's a hash key
+                } else {
+                    isTerminator = true;
+                }
+            } else {
+                isTerminator = true;
+            }
+        }
+        
+        if (token.type == LexerTokenType.EOF || isTerminator || token.text.equals("->")) {
             isEmptyList = true;
         } else if (token.text.equals("-")) {
             // -d, -e, -f, -l, -p, -x

src/main/java/org/perlonjava/parser/ParseInfix.java

@@ -95,7 +95,7 @@ public static Node parseInfixOperation(Parser parser, Node left, int precedence)
                     left = new StringNode(((IdentifierNode) left).name, ((IdentifierNode) left).tokenIndex);
                 }
                 token = peek(parser);
-                if (token.type == LexerTokenType.EOF || ParserTables.LIST_TERMINATORS.contains(token.text) || token.text.equals(",") || token.text.equals("=>")) {
+                if (token.type == LexerTokenType.EOF || ListParser.isListTerminator(parser, token) || token.text.equals(",") || token.text.equals("=>")) {
                     // "postfix" comma
                     return ListNode.makeList(left);
                 }

src/main/java/org/perlonjava/parser/ParsePrimary.java

@@ -214,6 +214,16 @@ static boolean isIsQuoteLikeOperator(String operator) {
      * @throws PerlCompilerException if the operator is not recognized or used incorrectly
      */
     static Node parseOperator(Parser parser, LexerToken token, String operator) {
+        // Check for autoquoting: keyword operators before => should be treated as barewords
+        // This handles cases like: and => {...}, or => {...}, xor => {...}
+        if (operator.equals("and") || operator.equals("or") || operator.equals("xor")) {
+            String peekTokenText = peek(parser).text;
+            if (peekTokenText.equals("=>")) {
+                // Autoquote: convert operator keyword to string literal
+                return new StringNode(token.text, parser.tokenIndex);
+            }
+        }
+        
         Node operand = null;
         switch (token.text) {
             case "(":

src/main/java/org/perlonjava/parser/PrototypeArgs.java

@@ -87,7 +87,7 @@ private static boolean allowsZeroArguments(String prototype) {
     private static boolean isArgumentTerminator(Parser parser) {
         var next = TokenUtils.peek(parser);
         return next.type == LexerTokenType.EOF ||
-                ParserTables.LIST_TERMINATORS.contains(next.text) ||
+                ListParser.isListTerminator(parser, next) ||
                 Parser.isExpressionTerminator(next) ||
                 // Assignment operators should terminate argument parsing
                 next.text.equals("=") ||