I remember using Amiga E, from a cover disk of CU Amiga.
Do I remember correctly that Amiga E had a "but" operator, which executes one statement but returns the value of the other? Never understood its point.
I thought it was one of those things that put Amiga ahead of competitors (because other systems had C/D). Oh my teenager brain.
That's some real esolang brain damage. Did somebody see the (four!) needlessly confusing increment and decrement operators in C and think this hadn't gone far enough?
It's not quite COME FROM but it sure is close for a supposedly useful language.
Why you'd use it? Probably for reducing statements to expressions, e.g.
PROC lower_delta(a1,a2,b1,b2) IS (da:=a2-a1) BUT (db:=b2-b1) BUT (IF da<db THEN da ELSE db)
tialaramex•7mo ago
That's just "I wish this was an expression language". Yeah, good idea, why isn't it?
type Num = i32; // Or whatever your preferred numeric type is
fn lower_delta(a1: Num, a2: Num, b1: Num, b2: Num) -> Num {
let da = a2 - a1;
let db = b2 - b1;
if da < db { da } else { db }
}
amiga386•7mo ago
A more useful example I found:
REPEAT
...
UNTIL CtrlC() OR (IF m:=GetMsg(wnd.userport) THEN ReplyMsg(m) BUT 1 ELSE 0)
Which means loop until Ctrl-C is pressed, or an IDCMP message comes to the window (which must be replied to allow the sender to reuse/free the message, but otherwise we don't care what's in the message, because we know it's either a keypress or a mouseclick, and both end the loop).
The comma operator, or "BUT", lets us capture the result of GetMsg(), go down a positive "we got a message so end the loop" path, but also fits in a ReplyMsg() so we don't have to deal with it anywhere else
tialaramex•7mo ago
Like I said though, you wanted an expression language, just have an expression language
postexitus•7mo ago
Do I remember correctly that Amiga E had a "but" operator, which executes one statement but returns the value of the other? Never understood its point.
I thought it was one of those things that put Amiga ahead of competitors (because other systems had C/D). Oh my teenager brain.
Edit: looks like I remember correctly!: https://cshandley.co.uk/JasonHulance/beginner_93.html
tialaramex•7mo ago
It's not quite COME FROM but it sure is close for a supposedly useful language.
amiga386•7mo ago
Why you'd use it? Probably for reducing statements to expressions, e.g.
tialaramex•7mo ago
amiga386•7mo ago
The comma operator, or "BUT", lets us capture the result of GetMsg(), go down a positive "we got a message so end the loop" path, but also fits in a ReplyMsg() so we don't have to deal with it anywhere else
tialaramex•7mo ago