Index: parse.y
===================================================================
--- parse.y	(revision 23490)
+++ parse.y	(working copy)
@@ -56,18 +56,25 @@
 	 ((id)&ID_SCOPE_MASK) == ID_CLASS))
 
 enum lex_state_e {
-    EXPR_BEG,			/* ignore newline, +/- is a sign. */
-    EXPR_END,			/* newline significant, +/- is an operator. */
-    EXPR_ENDARG,		/* ditto, and unbound braces. */
-    EXPR_ARG,			/* newline significant, +/- is an operator. */
-    EXPR_CMDARG,		/* newline significant, +/- is an operator. */
-    EXPR_MID,			/* newline significant, +/- is an operator. */
-    EXPR_FNAME,			/* ignore newline, no reserved words. */
-    EXPR_DOT,			/* right after `.' or `::', no reserved words. */
-    EXPR_CLASS,			/* immediate after `class', no here document. */
-    EXPR_VALUE			/* alike EXPR_BEG but label is disallowed. */
+    EXPR_BEG      =   (1 <<   0 ),	/* ignore newline, +/- is a sign */
+    EXPR_VALUE    =   (1 <<   1 ),	/* as EXPR_BEG but label is disallowed */
+    EXPR_MID      =   (1 <<   2 ),	/* newline significant, +/- is an operator */
+    EXPR_CLASS    =   (1 <<   3 ),	/* immediately after 'class', no here document */
+    EXPR_ARG      =   (1 <<   4 ),	/* newline significant, +/- is an operator */
+    EXPR_CMDARG   =   (1 <<   5 ),	/* newline significant, +/- is an operator */
+    EXPR_END      =   (1 <<   6 ),	/* newline significant, +/- is an operator */
+    EXPR_ENDARG   =   (1 <<   7 ),	/* as EXPR_END, unbound braces */
+    EXPR_FNAME    =   (1 <<   8 ),	/* ignore newline, no reserved words */
+    EXPR_DOT      =   (1 <<   9 ),	/* immediately after '.' or '::', no reserved words */
+      /* examine combinations */
+    EXPR_BEG_ANY  =  ( EXPR_BEG | EXPR_VALUE | EXPR_MID | EXPR_CLASS ),
+    EXPR_ARG_ANY  =  ( EXPR_ARG | EXPR_CMDARG ),
+    EXPR_END_ANY  =  ( EXPR_END | EXPR_ENDARG )
 };
 
+#define IS_lex_state(ls)	(lex_state & ( ls ))
+
+
 typedef VALUE stack_type;
 
 # define BITSTACK_PUSH(stack, n)	(stack = (stack<<1)|((n)&1))
@@ -6311,8 +6318,6 @@
     parser->enc = rb_enc_get(lex_lastline);
 }
 
-#define IS_ARG() (lex_state == EXPR_ARG || lex_state == EXPR_CMDARG)
-#define IS_BEG() (lex_state == EXPR_BEG || lex_state == EXPR_MID || lex_state == EXPR_VALUE || lex_state == EXPR_CLASS)
 
 static int
 parser_yylex(struct parser_params *parser)
@@ -6390,12 +6395,7 @@
 #endif
 	/* fall through */
       case '\n':
-	switch (lex_state) {
-	  case EXPR_BEG:
-	  case EXPR_FNAME:
-	  case EXPR_DOT:
-	  case EXPR_CLASS:
-	  case EXPR_VALUE:
+	if (IS_lex_state( EXPR_BEG | EXPR_VALUE | EXPR_CLASS | EXPR_FNAME | EXPR_DOT )) {
 #ifdef RIPPER
             if (!fallthru) {
                 ripper_dispatch_scan_event(parser, tIGNORED_NL);
@@ -6403,8 +6403,6 @@
             fallthru = Qfalse;
 #endif
 	    goto retry;
-	  default:
-	    break;
 	}
 	while ((c = nextc())) {
 	    switch (c) {
@@ -6454,28 +6452,28 @@
 		return tOP_ASGN;
 	    }
 	    pushback(c);
-	    if (IS_ARG() && space_seen && !ISSPACE(c)) {
+	    if (IS_lex_state( EXPR_ARG_ANY ) && space_seen && !ISSPACE(c)) {
 		rb_warning0("`*' interpreted as argument prefix");
 		c = tSTAR;
 	    }
-	    else if (IS_BEG()) {
+	    else if (IS_lex_state( EXPR_BEG_ANY )) {
 		c = tSTAR;
 	    }
 	    else {
 		c = '*';
 	    }
 	}
-	switch (lex_state) {
-	  case EXPR_FNAME: case EXPR_DOT:
-	    lex_state = EXPR_ARG; break;
-	  default:
-	    lex_state = EXPR_BEG; break;
+	if (IS_lex_state( EXPR_FNAME | EXPR_DOT )) {
+	    lex_state = EXPR_ARG;
 	}
+	else {
+	    lex_state = EXPR_BEG;
+	}
 	return c;
 
       case '!':
 	c = nextc();
-	if (lex_state == EXPR_FNAME || lex_state == EXPR_DOT) {
+	if (IS_lex_state( EXPR_FNAME | EXPR_DOT )) {
 	    lex_state = EXPR_ARG;
 	    if (c == '@') {
 		return '!';
@@ -6530,12 +6528,12 @@
 	    }
 	}
 
-	switch (lex_state) {
-	  case EXPR_FNAME: case EXPR_DOT:
-	    lex_state = EXPR_ARG; break;
-	  default:
-	    lex_state = EXPR_BEG; break;
+	if (IS_lex_state( EXPR_FNAME | EXPR_DOT )) {
+	    lex_state = EXPR_ARG;
 	}
+	else {
+	    lex_state = EXPR_BEG;
+	}
 	if ((c = nextc()) == '=') {
 	    if ((c = nextc()) == '=') {
 		return tEQQ;
@@ -6555,20 +6553,17 @@
       case '<':
 	c = nextc();
 	if (c == '<' &&
-	    lex_state != EXPR_END &&
-	    lex_state != EXPR_DOT &&
-	    lex_state != EXPR_ENDARG &&
-	    lex_state != EXPR_CLASS &&
-	    (!IS_ARG() || space_seen)) {
+	    !IS_lex_state( EXPR_END_ANY | EXPR_CLASS | EXPR_DOT ) &&
+	    (!IS_lex_state( EXPR_ARG_ANY ) || space_seen)) {
 	    int token = heredoc_identifier();
 	    if (token) return token;
 	}
-	switch (lex_state) {
-	  case EXPR_FNAME: case EXPR_DOT:
-	    lex_state = EXPR_ARG; break;
-	  default:
-	    lex_state = EXPR_BEG; break;
+	if (IS_lex_state( EXPR_FNAME | EXPR_DOT )) {
+	    lex_state = EXPR_ARG;
 	}
+	else {
+	    lex_state = EXPR_BEG;
+	}
 	if (c == '=') {
 	    if ((c = nextc()) == '>') {
 		return tCMP;
@@ -6589,12 +6584,12 @@
 	return '<';
 
       case '>':
-	switch (lex_state) {
-	  case EXPR_FNAME: case EXPR_DOT:
-	    lex_state = EXPR_ARG; break;
-	  default:
-	    lex_state = EXPR_BEG; break;
+	if (IS_lex_state( EXPR_FNAME | EXPR_DOT )) {
+	    lex_state = EXPR_ARG;
 	}
+	else {
+	    lex_state = EXPR_BEG;
+	}
 	if ((c = nextc()) == '=') {
 	    return tGEQ;
 	}
@@ -6615,11 +6610,11 @@
 	return tSTRING_BEG;
 
       case '`':
-	if (lex_state == EXPR_FNAME) {
+	if (IS_lex_state( EXPR_FNAME )) {
 	    lex_state = EXPR_END;
 	    return c;
 	}
-	if (lex_state == EXPR_DOT) {
+	if (IS_lex_state( EXPR_DOT )) {
 	    if (cmd_state)
 		lex_state = EXPR_CMDARG;
 	    else
@@ -6634,7 +6629,7 @@
 	return tSTRING_BEG;
 
       case '?':
-	if (lex_state == EXPR_END || lex_state == EXPR_ENDARG) {
+	if (IS_lex_state( EXPR_END_ANY )) {
 	    lex_state = EXPR_VALUE;
 	    return '?';
 	}
@@ -6644,7 +6639,7 @@
 	    return 0;
 	}
 	if (rb_enc_isspace(c, parser->enc)) {
-	    if (!IS_ARG()) {
+	    if (!IS_lex_state( EXPR_ARG_ANY )) {
 		int c2 = 0;
 		switch (c) {
 		  case ' ':
@@ -6725,20 +6720,20 @@
 	    return tOP_ASGN;
 	}
 	pushback(c);
-	if (IS_ARG() && space_seen && !ISSPACE(c)) {
+	if (IS_lex_state( EXPR_ARG_ANY ) && space_seen && !ISSPACE(c)) {
 	    rb_warning0("`&' interpreted as argument prefix");
 	    c = tAMPER;
 	}
-	else if (IS_BEG()) {
+	else if (IS_lex_state( EXPR_BEG_ANY )) {
 	    c = tAMPER;
 	}
 	else {
 	    c = '&';
 	}
-	switch (lex_state) {
-	  case EXPR_FNAME: case EXPR_DOT:
-	    lex_state = EXPR_ARG; break;
-	  default:
+	if (IS_lex_state( EXPR_FNAME | EXPR_DOT )) {
+	    lex_state = EXPR_ARG;
+	}
+	else {
 	    lex_state = EXPR_BEG;
 	}
 	return c;
@@ -6759,7 +6754,7 @@
 	    lex_state = EXPR_BEG;
 	    return tOP_ASGN;
 	}
-	if (lex_state == EXPR_FNAME || lex_state == EXPR_DOT) {
+	if (IS_lex_state( EXPR_FNAME | EXPR_DOT )) {
 	    lex_state = EXPR_ARG;
 	}
 	else {
@@ -6770,7 +6765,7 @@
 
       case '+':
 	c = nextc();
-	if (lex_state == EXPR_FNAME || lex_state == EXPR_DOT) {
+	if (IS_lex_state( EXPR_FNAME | EXPR_DOT )) {
 	    lex_state = EXPR_ARG;
 	    if (c == '@') {
 		return tUPLUS;
@@ -6783,9 +6778,9 @@
 	    lex_state = EXPR_BEG;
 	    return tOP_ASGN;
 	}
-	if (IS_BEG() ||
-	    (IS_ARG() && space_seen && !ISSPACE(c))) {
-	    if (IS_ARG()) arg_ambiguous();
+	if (IS_lex_state( EXPR_BEG_ANY ) ||
+	    (IS_lex_state( EXPR_ARG_ANY ) && space_seen && !ISSPACE(c))) {
+	    if (IS_lex_state( EXPR_ARG_ANY )) arg_ambiguous();
 	    lex_state = EXPR_BEG;
 	    pushback(c);
 	    if (c != -1 && ISDIGIT(c)) {
@@ -6800,7 +6795,7 @@
 
       case '-':
 	c = nextc();
-	if (lex_state == EXPR_FNAME || lex_state == EXPR_DOT) {
+	if (IS_lex_state( EXPR_FNAME | EXPR_DOT )) {
 	    lex_state = EXPR_ARG;
 	    if (c == '@') {
 		return tUMINUS;
@@ -6817,9 +6812,9 @@
 	    lex_state = EXPR_ARG;
 	    return tLAMBDA;
 	}
-	if (IS_BEG() ||
-	    (IS_ARG() && space_seen && !ISSPACE(c))) {
-	    if (IS_ARG()) arg_ambiguous();
+	if (IS_lex_state( EXPR_BEG_ANY ) ||
+	    (IS_lex_state( EXPR_ARG_ANY ) && space_seen && !ISSPACE(c))) {
+	    if (IS_lex_state( EXPR_ARG_ANY )) arg_ambiguous();
 	    lex_state = EXPR_BEG;
 	    pushback(c);
 	    if (c != -1 && ISDIGIT(c)) {
@@ -7082,15 +7077,14 @@
       case ':':
 	c = nextc();
 	if (c == ':') {
-	    if (IS_BEG() ||
-		lex_state == EXPR_CLASS || (IS_ARG() && space_seen)) {
+	    if (IS_lex_state( EXPR_BEG_ANY ) || (IS_lex_state( EXPR_ARG_ANY ) && space_seen)) {
 		lex_state = EXPR_BEG;
 		return tCOLON3;
 	    }
 	    lex_state = EXPR_DOT;
 	    return tCOLON2;
 	}
-	if (lex_state == EXPR_END || lex_state == EXPR_ENDARG || (c != -1 && ISSPACE(c))) {
+	if (IS_lex_state( EXPR_END_ANY ) || (c != -1 && ISSPACE(c))) {
 	    pushback(c);
 	    lex_state = EXPR_BEG;
 	    return ':';
@@ -7110,7 +7104,7 @@
 	return tSYMBEG;
 
       case '/':
-	if (IS_BEG()) {
+	if (IS_lex_state( EXPR_BEG_ANY )) {
 	    lex_strterm = NEW_STRTERM(str_regexp, '/', 0);
 	    return tREGEXP_BEG;
 	}
@@ -7120,19 +7114,19 @@
 	    return tOP_ASGN;
 	}
 	pushback(c);
-	if (IS_ARG() && space_seen) {
+	if (IS_lex_state( EXPR_ARG_ANY ) && space_seen) {
 	    if (!ISSPACE(c)) {
 		arg_ambiguous();
 		lex_strterm = NEW_STRTERM(str_regexp, '/', 0);
 		return tREGEXP_BEG;
 	    }
 	}
-	switch (lex_state) {
-	  case EXPR_FNAME: case EXPR_DOT:
-	    lex_state = EXPR_ARG; break;
-	  default:
-	    lex_state = EXPR_BEG; break;
+	if (IS_lex_state( EXPR_FNAME | EXPR_DOT )) {
+	    lex_state = EXPR_ARG;
 	}
+	else {
+	    lex_state = EXPR_BEG;
+	}
 	return '/';
 
       case '^':
@@ -7141,12 +7135,12 @@
 	    lex_state = EXPR_BEG;
 	    return tOP_ASGN;
 	}
-	switch (lex_state) {
-	  case EXPR_FNAME: case EXPR_DOT:
-	    lex_state = EXPR_ARG; break;
-	  default:
-	    lex_state = EXPR_BEG; break;
+	if (IS_lex_state( EXPR_FNAME | EXPR_DOT )) {
+	    lex_state = EXPR_ARG;
 	}
+	else {
+	    lex_state = EXPR_BEG;
+	}
 	pushback(c);
 	return '^';
 
@@ -7160,7 +7154,7 @@
 	return ',';
 
       case '~':
-	if (lex_state == EXPR_FNAME || lex_state == EXPR_DOT) {
+	if (IS_lex_state( EXPR_FNAME | EXPR_DOT )) {
 	    if ((c = nextc()) != '@') {
 		pushback(c);
 	    }
@@ -7172,11 +7166,11 @@
 	return '~';
 
       case '(':
-	if (IS_BEG()) {
+	if (IS_lex_state( EXPR_BEG_ANY )) {
 	    c = tLPAREN;
 	}
 	else if (space_seen) {
-	    if (IS_ARG()) {
+	    if (IS_lex_state( EXPR_ARG_ANY )) {
 		c = tLPAREN_ARG;
 	    }
 	}
@@ -7188,7 +7182,7 @@
 
       case '[':
 	paren_nest++;
-	if (lex_state == EXPR_FNAME || lex_state == EXPR_DOT) {
+	if (IS_lex_state( EXPR_FNAME | EXPR_DOT )) {
 	    lex_state = EXPR_ARG;
 	    if ((c = nextc()) == ']') {
 		if ((c = nextc()) == '=') {
@@ -7200,10 +7194,10 @@
 	    pushback(c);
 	    return '[';
 	}
-	else if (IS_BEG()) {
+	else if (IS_lex_state( EXPR_BEG_ANY )) {
 	    c = tLBRACK;
 	}
-	else if (IS_ARG() && space_seen) {
+	else if (IS_lex_state( EXPR_ARG_ANY ) && space_seen) {
 	    c = tLBRACK;
 	}
 	lex_state = EXPR_BEG;
@@ -7218,9 +7212,9 @@
 	    --paren_nest;
 	    return tLAMBEG;
 	}
-	if (IS_ARG() || lex_state == EXPR_END)
+	if (IS_lex_state( EXPR_ARG_ANY | EXPR_END ))
 	    c = '{';          /* block (primary) */
-	else if (lex_state == EXPR_ENDARG)
+	else if (IS_lex_state( EXPR_ENDARG ))
 	    c = tLBRACE_ARG;  /* block (expr) */
 	else
 	    c = tLBRACE;      /* hash */
@@ -7243,7 +7237,7 @@
 	return '\\';
 
       case '%':
-	if (IS_BEG()) {
+	if (IS_lex_state( EXPR_BEG_ANY )) {
 	    int term;
 	    int paren;
 
@@ -7315,15 +7309,15 @@
 	    lex_state = EXPR_BEG;
 	    return tOP_ASGN;
 	}
-	if (IS_ARG() && space_seen && !ISSPACE(c)) {
+	if (IS_lex_state( EXPR_ARG_ANY ) && space_seen && !ISSPACE(c)) {
 	    goto quotation;
 	}
-	switch (lex_state) {
-	  case EXPR_FNAME: case EXPR_DOT:
-	    lex_state = EXPR_ARG; break;
-	  default:
-	    lex_state = EXPR_BEG; break;
+	if (IS_lex_state( EXPR_FNAME | EXPR_DOT )) {
+	    lex_state = EXPR_ARG;
 	}
+	else {
+	    lex_state = EXPR_BEG;
+	}
 	pushback(c);
 	return '%';
 
@@ -7506,7 +7500,7 @@
 		result = tFID;
 	    }
 	    else {
-		if (lex_state == EXPR_FNAME) {
+		if (IS_lex_state( EXPR_FNAME )) {
 		    if ((c = nextc()) == '=' && !peek('~') && !peek('>') &&
 			(!peek('=') || (lex_p + 1 < lex_pend && lex_p[1] == '>'))) {
 			result = tIDENTIFIER;
@@ -7525,9 +7519,8 @@
 		}
 	    }
 
-	    if ((lex_state == EXPR_BEG && !cmd_state) ||
-		lex_state == EXPR_ARG ||
-		lex_state == EXPR_CMDARG) {
+	    if ((IS_lex_state( EXPR_BEG ) && !cmd_state) ||
+		IS_lex_state( EXPR_ARG_ANY )) {
 		if (peek(':') && !(lex_p + 1 < lex_pend && lex_p[1] == ':')) {
 		    lex_state = EXPR_BEG;
 		    nextc();
@@ -7535,7 +7528,7 @@
 		    return tLABEL;
 		}
 	    }
-	    if (mb == ENC_CODERANGE_7BIT && lex_state != EXPR_DOT) {
+	    if (mb == ENC_CODERANGE_7BIT && !IS_lex_state( EXPR_DOT )) {
 		const struct kwtable *kw;
 
 		/* See if it is a reserved word.  */
@@ -7557,11 +7550,11 @@
 			if (COND_P()) return keyword_do_cond;
 			if (CMDARG_P() && state != EXPR_CMDARG)
 			    return keyword_do_block;
-			if (state == EXPR_ENDARG || state == EXPR_BEG)
+			if (state & ( EXPR_BEG | EXPR_ENDARG ))
 			    return keyword_do_block;
 			return keyword_do;
 		    }
-		    if (state == EXPR_BEG || state == EXPR_VALUE)
+		    if (state & ( EXPR_BEG | EXPR_VALUE ))
 			return kw->id[0];
 		    else {
 			if (kw->id[0] != kw->id[1])
@@ -7571,9 +7564,7 @@
 		}
 	    }
 
-	    if (IS_BEG() ||
-		lex_state == EXPR_DOT ||
-		IS_ARG()) {
+	    if (IS_lex_state( EXPR_BEG_ANY | EXPR_ARG_ANY | EXPR_DOT )) {
 		if (cmd_state) {
 		    lex_state = EXPR_CMDARG;
 		}