Parser – Number Error Corrections

Qt functions are currently being used to convert strings of numbers to a double or an integer in the get number routine.  This routine will be changed to use STL functions.  While investigating this, a few problems were discovered with how some of the number errors were being reported.

The "expected sign or digits for exponent in floating point constant" error was being reported even when the exponent sign was present.  A new "expected digits for exponent in floating point constant" error for this situation.  When an incorrectly formed number contained a single decimal point followed by the start of an exponent ('E'), the "expected digits in mantissa of floating point constant" error only pointed to the decimal point.  The error was changed to point to both the decimal point and the 'E' character.

The translator was not reporting the "expected command" error correctly when there was a number error - the error was pointing to the number error which was either not at the beginning of the command or its length was not one.  This occurred because the number error was not correctly reported as an unexpected token error when a reference was request (at the beginning of a statement).

This was corrected by adding a reference argument to the get token translator routine with a default of None.  Only when this argument is None are number tokens allowed.  When an unknown token error is returned from the parser, the reference argument is used to generate the appropriate expected error status.  For the first token obtained from the get commands translator routine, this argument was set to All, which prevents number tokens (an unexpected token error is return for all number including number errors).

The get operands translator routine was modified to pass its reference argument directly to the get token call.  Since get token now generates the appropriate error for references, this routine no longer needs to intercept the error to return the appropriate error or set the error length to one for references.  The status is simply returned when the status is not Good.  The LET translate routine handles reporting errors when neither a command nor a reference starts a line.  The section handling errors was structured poorly and was rewritten.

Certain types of errors were reported differently as a result of these changes.  Previously, the error for an incorrect statement like 34=A was reported as an "expected item for assignment" error pointing to the 34.  Now the "expected command" error is reported pointing to only the first character of the number.  Both errors are technically correct, and it would be difficult to report the previous error.  The error was changed to "expected command or item for assignment" since both are applicable at the beginning of a statement.

The expected results for parser test #3 (numbers), translator tests #1 (assignments), #3 (more assignments), and #14 (parser errors) were updated for these changes.  Some addition tests were added to translator test #14 for the new expecting digits for exponent error.  Many of the translator tests results were also updated for the expected command message change.

[branch parser commit 20e46cc617]