On Wednesday, April 23, 2014 1:23:00 PM UTC+5:30, Steven D'Aprano wrote: > On Tue, 22 Apr 2014 23:57:46 -0700, Rustom Mody wrote:
> > On the other hand when/if a keyboard mapping is defined in which the > > characters that are commonly needed are available, it is reasonable to > > expect the ∨,∧ to cost no more than 2 strokes each (ie about as much as > > an 'A'; slightly more than an 'a'. Which means that '∨' is expected to > > cost about the same as 'or' and ∧ to cost less than an 'and' > Oh, a further thought... > Consider your example: > return year%4=0 ∧ (year%100≠0 ∨ year%100 = 0) > vs > return year%4=0 and (year%100!=0 or year%100 = 0) > [aside: personally I like ≠ and if there was a platform independent way > to type it in any editor, I'd much prefer it over != or <> ] > Apart from the memorization problem, which I've already touched on, there > is the mode problem. Keyboard layouts are modes, and you're swapping > modes. Every time you swap modes, there is a small mental cost. Think of > it as an interrupt which has to be caught, pausing the current thought > and starting a new one. So rather than: > char char char char char char char ... > you have: > char char char INTERRUPT > char INTERRUPT > char char char ... > which is a heavier cost that it appears from just counting keystrokes. Of > course, the more experienced you become, the smaller that cost will be, > but it will never be quite as low as just a "regular" keystroke. > Normally, when people use multiple keyboards, its because that interrupt > cost is amortized over a significant amount of typing: > INTERRUPT (English layout) > paragraph paragraph paragraph paragraph > INTERRUPT (Greek layout) > paragraph paragraph paragraph > INTERRUPT (English again) > paragraph ... > and possibly even lost in the noise of a far greater interrupt, namely > task-switching from one application to another. So it's manageable. But > switching layouts for a single character is likely to be far more > painful, especially for casual users of that layout. > Based on an extremely generous estimate that I use "lambda" four times in > 100 lines of code, I might use λ perhaps once in a thousand non-Greek > characters. Similarly, I might use ∧ or ∨ maybe once per hundred > characters. That means I'm unlikely to ever get familiar enough with > those that the cost of two interrupts per use will be negligible. Its gratifying to see an argument whose framing is cognitive-based! More on that later. For now: mode/modeless Yes most of us prefer the Shift key to the Caps Lock even for stretches of capitals. So analogously here is a modeless solution Earlier I found this mode-switching version $ setxkbmap -option "grp:switch,grp:alt_shift_toggle,grp_led:scroll" -layout "us,gr" this makes Shift-Alt the mode-switcher This one on the other hand $ setxkbmap -layout "us,gr" -option "grp:switch" will make right-alt behave like 'Greek-Shift' ie typing abcdefghijklmnopqrstuvwxyz with RAlt depressed throughout, produces αβψδεφγηιξκλμνοπ;ρστθωςχυζ This makes the a Greek letter's ergonomic cost identical to a capital English letter's: For Greek use RAlt the way one uses Shift for English. Notes: 1. Tried on Debian and Ubuntu -- Recent Ubuntus are rather more ill-mannered in the way they appropriates keys. Still it works as far as I can see. 2. ';' ?? ie semicolon is produced from 'q'? Whats that semicolon doing there?? But then Greek is -- well -- Greek to me! (As is xkb!) -- https://mail.python.org/mailman/listinfo/python-list
