[Gretl-devel] Greek-letter names

In current git and snapshots I've introduced a small amendment to the rules governing variable names in hansl. (Reminder: all ASCII, starts with a letter, contains nothing but letters, numerals and underscore; max 31 characters.) The newly acceptable exception to the prior rule is a single "math-greek" letter (in UTF-8), of which there are 24, for use in naming all types of variables except series. To make it easier to enter such characters there's a new facility in the GUI script editor and console: Alt+letter gets you a Greek letter (or Alt-Shift-letter for upper case). The Latin-Greek mapping is shown below. I'm not in favor of supporting arbitrary UTF-8 in variable names. That would be complicated (given all the instances of fixed-format printouts in gretl along with the fact that UTF-8 glyphs can take from one to four bytes) and IMO would be of no real benefit. But I do like the idea of being able to give parameters Greek-letter names (I'm primarily thinking of scalars and matrices); and since all the Greek letters in the math lexicon take two bytes, this is relatively easy to handle. Latin-Greek mapping (with Alt or Alt-Shift): a alpha b beta c chi d delta e epsilon f phi g gamma h eta i iota j psi k kappa l lambda m mu n nu o omicron p pi q theta r rho s sigma t tau u upsilon v nu (repeated) w omega x xi y upsilon (repeated) z zeta Allin