IMSUB and portable?

[Patrick Durusau <patrick@durusau.net>]

Greetings!

Should the following be a note:

A portable way to test equality is to use IMSUB to compute the difference, use IMABS to find the absolute difference, and then ensure the absolute difference is smaller than or equal to some nonnegative value (for exact equality, compare for equality with 0).

I ask because if an evaluator allows a TEXT type, IMSUB accepts complex. If the TEXT is not converted into Complex, then how it this a portable test of equality?

Seems to assume conversion to complex, which may not be the case.

Suggestions?

Thanks!

Patrick

-- 
Patrick Durusau
patrick@durusau.net
Chair, V1 - US TAG to JTC 1/SC 34
Convener, JTC 1/SC 34/WG 3 (Topic Maps)
Editor, OpenDocument Format TC (OASIS), Project Editor ISO/IEC 26300
Co-Editor, ISO/IEC 13250-1, 13250-5 (Topic Maps)