2.5.0.8 update

diff --git a/NEWS b/NEWS
index 035e04559ded134c8f7eac587700e00ae025bb4a..f50cd8314ef1d379456e1dc6c7b8aa790ad131ca 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -79,6 +79,9 @@ Changes between release 2.5.0.7 (06Mar95) and release 2.4.7:
                stdinit if unset ("%option nostdinit"), initialize yyin
                        and yyout statically to nil FILE* pointers, instead
                        of stdin and stdout
+               yylineno        if set, keep track of the current line
+                       number in global yylineno (this option is expensive
+                       in terms of performance)
                yywrap  if unset ("%option noyywrap"), scanner does not
                        call yywrap() upon EOF but simply assumes there
                        are no more files to scan
@@ -319,6 +322,9 @@ Changes between release 2.5.0.7 (06Mar95) and release 2.4.7:
 
        - input() no longer trashes yytext.
 
+       - interactive scanners now read characters in YY_INPUT up to a
+         newline, a large performance gain.
+
        - C++ scanner objects now work with the -P option.  You include
          <FlexLexer.h> once per scanner - see comments in <FlexLexer.h>
          (or flex.1) for details.
@@ -375,6 +381,9 @@ Changes between release 2.5.0.7 (06Mar95) and release 2.4.7:
          switches to new input files or different input buffers.  If you
          want to e.g., return to INITIAL, you must explicitly do so.
 
+       - The "Performance Considerations" section of the manual has been
+         updated.
+
        - Documented the "yy_act" variable, which when YY_USER_ACTION is
          invoked holds the number of the matched rule, and added an
          example of using yy_act to profile how often each rule is matched.

diff --git a/flex.1 b/flex.1
index 636c1c7418a6692c191a4f4c4b1f0b046fcd13ad..a64feacdb9f6546b869f8c9f6ef2320f5bd9ff1a 100644 (file)
--- a/flex.1
+++ b/flex.1
@@ -2167,7 +2167,8 @@ scanner.  If you give the flag twice, you will also get comments regarding
 features that lead to minor performance losses.
 .IP
 Note that the use of
-.B REJECT
+.B REJECT,
+.B %option yylineno,
 and variable trailing context (see the Deficiencies / Bugs section below)
 entails a substantial performance penalty; use of
 .I yymore(),
@@ -2589,6 +2590,7 @@ Here are all of the names affected:
     yyin
     yyleng
     yylex
+    yylineno
     yyout
     yyrestart
     yytext
@@ -2719,6 +2721,15 @@ pointers, instead of
 and
 .I stdout.
 .TP
+.B yylineno
+directs
+.I flex
+to generate a scanner that maintains the number of the current line
+read from its input in the global variable
+.B yylineno.
+This option is implied by
+.B %option lex-compat.
+.TP
 .B yywrap
 if unset (i.e.,
 .B %option noyywrap),
@@ -2819,9 +2830,13 @@ are, from most expensive to least:
 .nf
 
     REJECT
+    %option yylineno
+    arbitrary trailing context
 
     pattern sets that require backing up
-    arbitrary trailing context
+    %array
+    %option interactive
+    %option always-interactive
 
     '^' beginning-of-line operator
     yymore()
@@ -3155,7 +3170,9 @@ You can also use
 .I flex
 to generate a C++ scanner class, using the
 .B \-+
-option, which is automatically specified if the name of the flex
+option (or, equivalently,
+.B %option c++),
+which is automatically specified if the name of the flex
 executable ends in a '+', such as
 .I flex++.
 When using this option, flex defaults to generating the scanner to the file
@@ -3178,6 +3195,27 @@ returns the text of the most recently matched token, the equivalent of
 .B int YYLeng()
 returns the length of the most recently matched token, the equivalent of
 .B yyleng.
+.TP
+.B int lineno() const
+returns the current input line number
+(see
+.B %option yylineno),
+or
+.B 1
+if
+.B %option yylineno
+was not used.
+.TP
+.B void set_debug( int flag )
+sets the debugging flag for the scanner, equivalent to assigning to
+.B yy_flex_debug
+(see the Options section above).  Note that you must build the scanner
+using
+.B %option debug
+to include debugging information in it.
+.TP
+.B int debug() const
+returns the current setting of the debugging flag.
 .PP
 Also provided are member functions equivalent to
 .B yy_switch_to_buffer(),
@@ -3459,6 +3497,8 @@ scanner internal variable
 .B yylineno
 is not supported unless
 .B \-l
+or
+.B %option yylineno
 is used.
 .IP
 yylineno is not part of the POSIX specification.