Comments on: Flex and Bison in C++: An Example

By: johndescs

johndescs — Thu, 24 Nov 2011 17:16:50 +0000

A huge thanks for the example. All around were only snippets so you tarball was very welcome.

For information it lasted me around 6 hours to convert a simple C flex-bison to C++.

By: Allan

Allan — Fri, 28 Oct 2011 17:46:32 +0000

Hi! Thanks for the code. Is really helping me.

How can I change the yyin in this case? In the regular FLEX/BISON I just assign a FILE to yyin in the main. I don’t know what to do in this case.

Thanks in advance

By: Albi

Albi — Sat, 22 Oct 2011 21:29:56 +0000

Hi man! Thanks for this piece of code. It’s been really helpful.

By: daniel

daniel — Mon, 16 May 2011 14:58:35 +0000

I mean answers for John and Jung concerning compiling your example in windows with g++ or with visual c++ 6.0 dev studio (not .NET)

By: daniel

daniel — Mon, 16 May 2011 14:56:38 +0000

Robert have you got any answers for jung? I am also struggling with the errors.
Thanks
Daniel

By: jung

jung — Sat, 05 Feb 2011 03:45:58 +0000

hmm. skip special characters.

* FlexLexer.h line 47
-#include iostream.h
+#include iostream
+using std::istream;
+using std::ostream;

* lex.yy.cc line 23~25
-#include stdlib.h
-class istream;
-#include unistd.h
+#include stdio.h
+#include stdlib.h
+#include iostream
+using namespace std ;

By: jung

jung — Sat, 05 Feb 2011 03:43:40 +0000

hi.
now i tested your example code on mingw.

here g++ (mingw) compile method.

> g++ lex.yy.cc Main.cpp waffleshop.tab.c -o waffleshop
> returns quite a lot error reports.

modify FlexLexer.h and lex.yy.cc files like below. ( – remove + add)

* FlexLexer.h line 47
-#include
+#include
+using std::istream;
+using std::ostream;

* lex.yy.cc line 23~25
-#include
-class istream;
-#include
+#include
+#include
+#include
+using namespace std ;

* result
C:\ex\parser>waffleshop
10
INTEGER / 5 = 2
HI
5
INTEGER / 5 = 1
200
INTEGER / 5 = 40
^C

;-)

By: Robert Hollencamp

Robert Hollencamp — Wed, 01 Sep 2010 15:30:01 +0000

The WTFPL sounds good to me; if you would prefer a different license let me know. Leaving a post saying 'this is useful, thanks' would be great, but there are absolutely no restrictions on what you do with the code.

By: Micah Villmow

Micah Villmow — Tue, 31 Aug 2010 23:19:57 +0000

Robert,
What is the code license on your examples?
Thanks,

By: Robert Hollencamp

Robert Hollencamp — Sun, 27 Jun 2010 05:31:01 +0000

I didn't try building this particular project, but I have worked with bison and flex in Visual Studio. You will need Bison and Flex. Microsoft provides a custom build rule for Visual Studio that makes it fairly easy to integrate these tools into the VS IDE.