Buffer Issue Resolution Document (BIRD) BIRD ID#: 26 ISSUE TITLE: General syntax rules an guidelines on TAB character usage REQUESTOR: Arpad Muranyi, Intel Corporation, Folsom, CA DATE SUBMITTED: March 20, 1995 DATE ACCEPTED BY IBIS OPEN FORUM: May 26, 1995 ******************************************************************************* ******************************************************************************* STATEMENT OF THE ISSUE: Even though TAB characters are allowed in IBIS files and their usage is legal, there are times when their use can cause problems. For example, in conjunction with the 80 character/line limitation, the golden parser might issue error messages with IBIS files in which the TAB characters were converted to SPACE characters, but were error free before the conversion took place. At such conversions a TAB character is usually replaced by several SPACE characters. This can turn a line originally less than 80 characters into lines more than 80 characters long. Conversions like this are usually done by text editors and file transfering software and may take place unnoticed by the user. ******************************************************************************* STATEMENT OF THE RESOLVED SPECIFICATIONS: A new section should be added to the General sytax rules and guidelines section which recommends that TAB characters should be avoided if possible. | General syntax rules and guidelines: | | . | | . | | . | | 10) The usage of TAB characters is legal, but they should be avoided as far | | as possible. This is to eliminate possible complications which might arise | | in situations when TAB characters are automatically converted to multiple | | spaces by text editing, file transfering and similar software. In cases | | like that, lines might become longer than 80 characters which is illegal in | | IBIS files. | ******************************************************************************* ANALYSIS PATH/DATA THAT LED TO SPECIFICATION: A user of an IBIS file reported that the Golden parser generated error messages with IBIS files which he downloaded from the vhdl.org machine. These IBIS files were error free when checked with the Golden parser before and after posting. The problem was localized to those lines in the IBIS file in question, which were 76 characters long and contained a TAB character. During the user's downloading process these TABs were converted to eight spaces resulting in 84 character lines which are illegal in IBIS. ******************************************************************************* ANY OTHER BACKGROUND INFORMATION: *******************************************************************************