Translator – Assignments (Release)

The test code was modified to output “<ref>” after tokens that have the reference flag set. For the third set of test inputs used for testing arrays and function, there are some differences because the reference flag is now set for array subscripts and function arguments. The unexpected comma error was also changed (replaced with separate unexpected comma errors). For the assignment statement test inputs (fifth set), a lot of different statements were needed to test the many situations that can occur. Many have already been discussed. As bugs were discovered, new test statements were added. There are 9 new possible assignment related errors, so there are statements for each of these.

Some more comma related bugs were discovered, including assigning an multiple dimension array element as in the statement “A(B,C)=D” added an assign list operator instead of an assign operator; and the statement “A(B+C,D=E)=F” generated an error. The bottom line was that the counter stack not empty check also needed to be added to the comma operator code. This resulted in new error “unexpected comma in parentheses” being added.

I'm changing the way the changes made to the code are dated. Previously, all the dates were changed to the date of the release – like all these changes were made the same day, which may not have been the case. The changes are becoming rather involved over many days and this method is not efficient. From this release on, the date will be when the changes are actually made. The time stamp of the file may be more recent because of going back and editing the change history at the top of the file.

I have also decided to put this project under software version control, specifically CVS – with the next release. I have working knowledge of CVS and I discovered that either MSYS came with it, or I installed an MSYS/CVS package. The current version numbers in the source files will be removed and replaced with the CVS revision ID tag. These versions were my attempt at version control anyway. Maintaining all the difference versions as zip files and directories is also not efficient.

The code now handles assignment statements and ibcp_0.1.8-src.zip has been uploaded at Sourceforge IBCP Project along with the binary for the program. The release notes now contain a Planned Roadmap to show upcoming development. Next the handling of data types...

Translator – Assignments and Parentheses

Simply changing the mode to Expression when an open parentheses occurs is insufficient. Statements like “A(B,C)=D” no longer worked correctly because the mode was not set to Command when the equal was processed. Also, statements like “A(B+C)=D” and especially “A(B=C)=D” need to have the mode temporarily set to Expression to process the operators in the subscripts correctly. Simply checking if the counter stack is not empty is sufficient for detecting this situation.  The logic for open parentheses needs to be:

Counter Stack Not Empty: No need to check mode; push open parentheses token on hold stack and push a 0 on the counter stack (which prevents commas).

Command: Return an “unexpected parentheses in command” error. Statements like “(A=B)” and “(A+B)” are not valid.

Equal: Set mode to Expression. This is the start of the expression after an equal (assignment). This will handle statements like “A=(B=3)” and “A=(B)=3” where the expression starts after the open parentheses.

Comma: Return an “unexpected parentheses in assignment list” error. Statements like “A,(B),C=4” are not valid.

Expression: Same as if counter stack is not empty (push token and 0).

When processing a closing parentheses for an open parentheses (not an array or function), the reference flag of the last token added to the output list needs to be cleared. A pointer to this token is on top of the done stack. If this token is an operator like in the expression “(A+B)” then clearing the reference flag has no effect, but in statements like “A=(B)=3” or “A=Function((B),C)” the reference flag of B is cleared.

The counter stack is not empty check also needs to be made when processing operators before checking the mode. In other words, if the counter is not empty, then it is assumed that the Translator is within an expression. This will handle statements like “A(B+C)=D” and “A(B=C)=D” correctly. So this check is needed at both the equal operator section and the no special operator section.  Looks like everything is working correctly, so almost ready to release...