Lex, Yacc, Flex, Bison: Overview, Documentation, Tools, Pointers. A compiler or interptreter for a programminning language is often decomposed into two. In computer science, Backus–Naur form or Backus normal form (BNF) is a notation technique for context-free grammars, often used to describe the syntax of languages used in computing, such as computer programming languages, document formats, instruction sets and communication protocols.
LEX & YACC Release Notes MKS LEX & YACC Release Notes Release 3.3.1 MKS Software Inc. 12450 Fair Lakes Circle, Suite 400 Fairfax VA 22033 USA Support: +1-703-803-7660 +1-703-803-3343 March 2001 Contents Changes in MKS LEX & YACC Release 3.3.1 include: • The -i option has been added to the lex command to make it easier to use mulitple grammars (each with its own lexical analyer) in a single program.
• The reference pages have been updated to match the format of the MKS Toolkit reference pages. • The -v and -V options for the yacc command now behave properly when reduce errors occur. • LEX now features improved generation of #line directives. • YACC features improved handling of large grammars. • The -p option for both the lex and yacc commands now replace all appropriate prefixes. • Support for Microsoft Windows Millennium has been added. For more information on these changes, see below.
MKS LEX & YACC Release 3.3 features the following changes from previous releases: • Increased support for Windows development. This includes the new LEX & YACC add-in for Microsoft Visual Studio 6.0. • Complete online documentation. • Support for DOS, OS/2, and Pascal has been dropped. • LEX & YACC now generate tables that do not cause truncation warnings with the Microsoft Visual C compiler or other compilers that are strict about ANSI C compliance. • Code generated with the -w option of lex and yacc no longer causes compiler errors due to the use of the far keyword. Documentation for MKS LEX & YACC is divided into two parts: • HTML Help files • ASCII reference pages To properly read the online HTML Help files, you must have Microsoft Internet Explorer 4.0 or later installed on your system.
It does not need to be your default browser. The HTML Help files provide the following documentation: • LEX & YACC Tutorial • LEX Programming Guide • YACC Programming Guide • LEX & YACC Reference Pages • LEX & YACC Release Notes You can access the online reference pages for the command line utilities provided in MKS LEX & YACC either through the Help button of the Microsoft Visual Studio add-in or by using the command line man utility to view the ASCII reference pages. To access a command's reference page, type man cmd_name For example, to get the reference page for the yacc command, you would type man yacc To access a miscellaneous information page, type man 5 page_name For example, to see the miscellaneous information page for yacc, you would type man 5 yacc MKS LEX & YACC 3.3.1 supports the following platforms: • Windows 2000 for Intel processors • Windows NT version 4.0 for Intel processors • Windows 95/98/Millennium Note the Microsoft Visual Studio add-in does not work for versions of Visual Studio before 6.0. To uninstall MKS LEX & YACC: • Run Add/Remove Programs from the control panel. • Remove MKS LEX & YACC. There is a known problem uninstalling MKS LEX & YACC on Windows 2000 using the control panel's Add/Remove Programs application.
The uninstall information is not deleted and the Start menu is not cleaned up. All other executable and support files are removed. Attempting to run the Lex and Yacc Configuration item from the Start menu or to uninstall MKS LEX & YACC again from the control panel results in a ' Fatal error during installation' message being displayed. To completely uninstall MKS LEX & YACC on Windows 2000, run setup.exe from the original distribution media and select Remove from the opening screen. When you have both MKS LEX & YACC and MKS Toolkit (Version 7.0+) installed on your system, several issues arise because of the inclusion of the SCO versions of the lex and yacc utilities in MKS Toolkit for Enterprise Developers. Getting the Right Reference Pages On a system with both MKS LEX & YACC and MKS Toolkit, typing one of the following: man lex man yacc displays the plain text version of the reference page for SCO lex or SCO yacc, respectively.
To display the plain text reference pages for the MKS lex and yacc utilities, you must type one of these commands: man mks_lex man mks_yacc Also, the HTML Help versions of the MKS LEX & YACC reference pages are not viewable with the MKS Toolkit man -h command. You can view them as described earlier or by typing%ROOTDIR%/etc/help/lyref.chm at the Windows NT/2000 command prompt or $ROOTDIR/etc/help/lyref.chm at the MKS KornShell command prompt. Getting the Right Executable On a system with both MKS LEX & YACC and MKS Toolkit for Enterprise Developers installed, you should ensure root_dir /mksnt comes before root_dir /bin (where root_dir is the directory in which) in your Path environment variable value. This ensures that you are running the lex and yacc utilities from MKS LEX & YACC as opposed to the SCO lex and yacc utilities from MKS Toolkit. To access the SCO versions, you can type one of the following at the Windows NT/2000 command prompt:%ROOTDIR%/bin/lex%ROOTDIR%/bin/yacc or one of these at the MKS KornShell command prompt: $ROOTDIR/bin/lex $ROOTDIR/bin/yacc To receive support for your MKS Software product, you must buy a Preferred Customer Support (PCS) contract for that product.