Sync backend/parser/scan.l with bin/psql/psqlscan.l.

Make some minor formatting adjustments to make it easier to diff these
files and see that they indeed implement the same flex rules (at least
to the extent that we want them to be the same).

(Someday it'd be nice to make ecpg's pgc.l more easily diff'able too,
but today is not that day.)

Also run relevant parts of these files and psqlscanslash.l through
pgindent.

No actual behavioral changes here, just obsessive neatnik-ism.

src/bin/psql/psqlscan.l

@@ -78,8 +78,8 @@ extern void psql_yyset_column(int column_no, yyscan_t yyscanner);
  * src/backend/parser/scan.l so far as the flex patterns are concerned.
  * The rule bodies are just ECHO as opposed to what the backend does,
  * however.  (But be sure to duplicate code that affects the lexing process,
- * such as BEGIN().)  Also, psqlscan uses a single <<EOF>> rule whereas
- * scan.l has a separate one for each exclusive state.
+ * such as BEGIN() and yyless().)  Also, psqlscan uses a single <<EOF>> rule
+ * whereas scan.l has a separate one for each exclusive state.
  */
 
 /*
@@ -351,11 +351,10 @@ other			.
 
 		/*
 		 * Force flex into the state indicated by start_state.  This has a
-		 * couple of purposes: it lets some of the functions below set a
-		 * new starting state without ugly direct access to flex variables,
-		 * and it allows us to transition from one flex lexer to another
-		 * so that we can lex different parts of the source string using
-		 * separate lexers.
+		 * couple of purposes: it lets some of the functions below set a new
+		 * starting state without ugly direct access to flex variables, and it
+		 * allows us to transition from one flex lexer to another so that we
+		 * can lex different parts of the source string using separate lexers.
 		 */
 		BEGIN(cur_state->start_state);
 %}
@@ -390,9 +389,7 @@ other			.
 
 <xc>{xcstop}	{
 					if (cur_state->xcdepth <= 0)
-					{
 						BEGIN(INITIAL);
-					}
 					else
 						cur_state->xcdepth--;
 					ECHO;
@@ -447,7 +444,7 @@ other			.
 				}
 
 {xnstart}		{
-					yyless(1);				/* eat only 'n' this time */
+					yyless(1);	/* eat only 'n' this time */
 					ECHO;
 				}
 
@@ -474,6 +471,7 @@ other			.
 				}
 <xus>{quotestop} |
 <xus>{quotefail} {
+					/* throw back all but the quote */
 					yyless(1);
 					BEGIN(xusend);
 					ECHO;
@@ -547,7 +545,7 @@ other			.
 						 * the $... part to the output, but put back the final
 						 * $ for rescanning.  Consider $delim$...$junk$delim$
 						 */
-						yyless(yyleng-1);
+						yyless(yyleng - 1);
 					}
 					ECHO;
 				}
@@ -682,8 +680,8 @@ other			.
 
 :{variable_char}+	{
 					/* Possible psql variable substitution */
-					char   *varname;
-					char   *value;
+					char	   *varname;
+					char	   *value;
 
 					varname = psqlscan_extract_substring(cur_state,
 														 yytext + 1,
@@ -717,8 +715,8 @@ other			.
 					else
 					{
 						/*
-						 * if the variable doesn't exist we'll copy the
-						 * string as is
+						 * if the variable doesn't exist we'll copy the string
+						 * as is
 						 */
 						ECHO;
 					}
@@ -766,9 +764,9 @@ other			.
 					 * Note that slash-star or dash-dash at the first
 					 * character will match a prior rule, not this one.
 					 */
-					int		nchars = yyleng;
-					char   *slashstar = strstr(yytext, "/*");
-					char   *dashdash = strstr(yytext, "--");
+					int			nchars = yyleng;
+					char	   *slashstar = strstr(yytext, "/*");
+					char	   *dashdash = strstr(yytext, "--");
 
 					if (slashstar && dashdash)
 					{
@@ -790,12 +788,12 @@ other			.
 					 * sequences of SQL operators.
 					 */
 					while (nchars > 1 &&
-						   (yytext[nchars-1] == '+' ||
-							yytext[nchars-1] == '-'))
+						   (yytext[nchars - 1] == '+' ||
+							yytext[nchars - 1] == '-'))
 					{
-						int		ic;
+						int			ic;
 
-						for (ic = nchars-2; ic >= 0; ic--)
+						for (ic = nchars - 2; ic >= 0; ic--)
 						{
 							if (strchr("~!@#^&|`?%", yytext[ic]))
 								break;
@@ -825,7 +823,7 @@ other			.
 				}
 {decimalfail}	{
 					/* throw back the .., and treat as integer */
-					yyless(yyleng-2);
+					yyless(yyleng - 2);
 					ECHO;
 				}
 {real}			{
@@ -838,12 +836,12 @@ other			.
 					 * but since this case will almost certainly lead to a
 					 * syntax error anyway, we don't bother to distinguish.
 					 */
-					yyless(yyleng-1);
+					yyless(yyleng - 1);
 					ECHO;
 				}
 {realfail2}		{
 					/* throw back the [Ee][+-], and proceed as above */
-					yyless(yyleng-2);
+					yyless(yyleng - 2);
 					ECHO;
 				}
 
@@ -856,15 +854,11 @@ other			.
 					ECHO;
 				}
 
-	/*
-	 * psql uses a single <<EOF>> rule, unlike the backend.
-	 */
-
 <<EOF>>			{
 					if (cur_state->buffer_stack == NULL)
 					{
 						cur_state->start_state = YY_START;
-						return LEXRES_EOL; /* end of input reached */
+						return LEXRES_EOL;		/* end of input reached */
 					}
 
 					/*
@@ -1192,8 +1186,8 @@ psqlscan_push_new_buffer(PsqlScanState state, const char *newstr,
 	stackelem = (StackElem *) pg_malloc(sizeof(StackElem));
 
 	/*
-	 * In current usage, the passed varname points at the current flex
-	 * input buffer; we must copy it before calling psqlscan_prepare_buffer()
+	 * In current usage, the passed varname points at the current flex input
+	 * buffer; we must copy it before calling psqlscan_prepare_buffer()
 	 * because that will change the buffer state.
 	 */
 	stackelem->varname = varname ? pg_strdup(varname) : NULL;
@@ -1301,11 +1295,11 @@ psqlscan_prepare_buffer(PsqlScanState state, const char *txt, int len,
 	else
 	{
 		/* Gotta do it the hard way */
-		int		i = 0;
+		int			i = 0;
 
 		while (i < len)
 		{
-			int		thislen = PQmblen(txt + i, state->encoding);
+			int			thislen = PQmblen(txt + i, state->encoding);
 
 			/* first byte should always be okay... */
 			newtxt[i] = txt[i];
@@ -1337,13 +1331,13 @@ psqlscan_emit(PsqlScanState state, const char *txt, int len)
 	{
 		/* Gotta do it the hard way */
 		const char *reference = state->refline;
-		int		i;
+		int			i;
 
 		reference += (txt - state->curline);
 
 		for (i = 0; i < len; i++)
 		{
-			char	ch = txt[i];
+			char		ch = txt[i];
 
 			if (ch == (char) 0xFF)
 				ch = reference[i];
@@ -1369,13 +1363,13 @@ psqlscan_extract_substring(PsqlScanState state, const char *txt, int len)
 	{
 		/* Gotta do it the hard way */
 		const char *reference = state->refline;
-		int		i;
+		int			i;
 
 		reference += (txt - state->curline);
 
 		for (i = 0; i < len; i++)
 		{
-			char	ch = txt[i];
+			char		ch = txt[i];
 
 			if (ch == (char) 0xFF)
 				ch = reference[i];
@@ -1391,7 +1385,7 @@ psqlscan_extract_substring(PsqlScanState state, const char *txt, int len)
  *
  * If the variable name is found, escape its value using the appropriate
  * quoting method and emit the value to output_buf.  (Since the result is
- * surely quoted, there is never any reason to rescan it.)  If we don't
+ * surely quoted, there is never any reason to rescan it.)	If we don't
  * find the variable or escaping fails, emit the token as-is.
  */
 void

src/bin/psql/psqlscanslash.l

@@ -113,11 +113,10 @@ other			.
 
 		/*
 		 * Force flex into the state indicated by start_state.  This has a
-		 * couple of purposes: it lets some of the functions below set a
-		 * new starting state without ugly direct access to flex variables,
-		 * and it allows us to transition from one flex lexer to another
-		 * so that we can lex different parts of the source string using
-		 * separate lexers.
+		 * couple of purposes: it lets some of the functions below set a new
+		 * starting state without ugly direct access to flex variables, and it
+		 * allows us to transition from one flex lexer to another so that we
+		 * can lex different parts of the source string using separate lexers.
 		 */
 		BEGIN(cur_state->start_state);
 %}
@@ -228,8 +227,8 @@ other			.
 						ECHO;
 					else
 					{
-						char   *varname;
-						char   *value;
+						char	   *varname;
+						char	   *value;
 
 						varname = psqlscan_extract_substring(cur_state,
 															 yytext + 1,
@@ -396,15 +395,11 @@ other			.
 
 }
 
-	/*
-	 * psql uses a single <<EOF>> rule, unlike the backend.
-	 */
-
 <<EOF>>			{
 					if (cur_state->buffer_stack == NULL)
 					{
 						cur_state->start_state = YY_START;
-						return LEXRES_EOL; /* end of input reached */
+						return LEXRES_EOL;		/* end of input reached */
 					}
 
 					/*