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And we're still using '*' for multiplication in our programming languages instead of '×' because using anything other than ASCII for programming is just too har

And we're still using '*' for multiplication in our programming languages instead of '×' because using anything other than ASCII for programming is just too hard, or too weird, or whatever.

scott_s 14y ago
To be fair, I prefer dots over crosses for multiplication of scalars in when I write it myself. I tend to assume a cross means cross product instead of scalar multiplication. (But, oddly, I do not assume that a dot means dot product.)
- milliams 14y ago
  But even in that case, people are using the full-stop '.' rather than the middle dot '·'
  - scott_s 14y ago
    They are? I use a middle dot. (I'm talking about when I write on paper or a board.)
sp332 14y ago
We already tried going full-APL but it only proved that it wasn't a good idea. I mean this is impressive https://www.youtube.com/watch?v=a9xAKttWgP4 https://www.youtube.com/watch?v=a9xAKttWgP4 but I still think the notation is too obscure.
- tel 14y ago
  Full APL isn't just unicode, though, it's also a total commitment to single-character operators as the primary language construct. Take a look at some Agda or Unicode-enabled Haskell code to see it really improving readability... though hampering type-ability.
  - Peaker 14y ago
    Agda's use of Unicode makes it far less readable to me. Readability is a subjective thing, of course.
    - tel 14y ago
      Fair. It's definitely in the eye of the beholder.
- recuter 14y ago
  As opposed to the many different and less terse idioms you have to do with regular languages? :) Everything is alien before it becomes familiar, I think a condensed guide to get people up to speed on the symbols is all that's necessary. APL doesn't feel like a weird throwback, it feels like it is from the future.
- vorg 14y ago
  > We already tried going full-APL but it only proved that it wasn't a good idea. When you say full-APL do you mean in one leap? Then I agree it's not a good idea, but how about going to APL in stages? First introduce just some operators (e.g. × ∧ ∨ ∈ ≥ ≤ ≠ → ⇒ only), then introduce more gradually until all APL operators are in use? Then keep on introducing other symbols from Unicode not in APL.
  - sp332 14y ago
    Well I used "we" continuing ruther's sense of "programmers in general". I didn't really do APL myself. I think it was Alan Kay who said: we needed to make APL to know what going too far looked like, that way we could stop wondering if we could do better by going further.
rmccue 14y ago
More likely, it's because we don't have them on our keyboards. Programming languages are usually about reducing friction for programmers, but using the proper multiplication/division symbols would increase that for most people.
- simonh 14y ago
  My best guess would be that we use * for multiplication because x being alphanumeric is a valid variable name. regarding keyboard presence, this is one of the things that irks me about Mac keyboards is the absence of the # character. I write little programs and scripts on my mac infrequently enough that I have to look up how to type it every blasted time. That, and how to take screenshots. The "Print Scrn" key on PCs spoils me.
  - Uncompetative 14y ago
    X = Y x Z B = T ^ F v T P = Q n R u S C = U cross V D = U dot V Area = Width by Height i.e. just capitalising names means that you can define macros that operate as infix operators: L . R -> L dot R L dot R -> Dot[L, R]
    - jewbacca 14y ago
      What language are you referring to? I'm not quite sure I understand your examples. -------- Related: In Haskell, any 2-argument function can be used (or defined) infix by surrounding it with backticks, eg: add 2 3 is equivalent to: 2 `add` 3 ---- And you can use this to cleanly write curried functions (often predicates) with their arguments flipped, eg: vowelCount = length . filter (`elem` "aeiou") ---- Note that functions named with punctuation characters are infix by default, and one can be used/defined prefix by surrounding it with brackets, eg: (<$>) = fmap toUpper <$> "aeiou" # => "AEIOU" ---- It's also convenient for resolving a subset of one of the harder problems in computer science: naming things. For a 2-argument function, use it infix and read it as a phrase in english. Which is clearer: ".jpg" `isSuffix` url or: ".jpg" `isSuffixOf` url You can also define functions' precedence and associativity (left/right) when used as an infix operator.

And we're still using '*' for multiplication in our programming languages instead of '×' because using anything other than ASCII for programming is just too hard, or too weird, or whatever.

scott_s 14y ago

To be fair, I prefer dots over crosses for multiplication of scalars in when I write it myself. I tend to assume a cross means cross product instead of scalar multiplication. (But, oddly, I do not assume that a dot means dot product.)

milliams 14y ago
But even in that case, people are using the full-stop '.' rather than the middle dot '·'
- scott_s 14y ago
  They are? I use a middle dot. (I'm talking about when I write on paper or a board.)

sp332 14y ago

We already tried going full-APL but it only proved that it wasn't a good idea. I mean this is impressive https://www.youtube.com/watch?v=a9xAKttWgP4 https://www.youtube.com/watch?v=a9xAKttWgP4 but I still think the notation is too obscure.

tel 14y ago
Full APL isn't just unicode, though, it's also a total commitment to single-character operators as the primary language construct. Take a look at some Agda or Unicode-enabled Haskell code to see it really improving readability... though hampering type-ability.
- Peaker 14y ago
  Agda's use of Unicode makes it far less readable to me. Readability is a subjective thing, of course.
  - tel 14y ago
    Fair. It's definitely in the eye of the beholder.
recuter 14y ago
As opposed to the many different and less terse idioms you have to do with regular languages? :) Everything is alien before it becomes familiar, I think a condensed guide to get people up to speed on the symbols is all that's necessary. APL doesn't feel like a weird throwback, it feels like it is from the future.
vorg 14y ago
> We already tried going full-APL but it only proved that it wasn't a good idea. When you say full-APL do you mean in one leap? Then I agree it's not a good idea, but how about going to APL in stages? First introduce just some operators (e.g. × ∧ ∨ ∈ ≥ ≤ ≠ → ⇒ only), then introduce more gradually until all APL operators are in use? Then keep on introducing other symbols from Unicode not in APL.
- sp332 14y ago
  Well I used "we" continuing ruther's sense of "programmers in general". I didn't really do APL myself. I think it was Alan Kay who said: we needed to make APL to know what going too far looked like, that way we could stop wondering if we could do better by going further.

rmccue 14y ago

More likely, it's because we don't have them on our keyboards. Programming languages are usually about reducing friction for programmers, but using the proper multiplication/division symbols would increase that for most people.

simonh 14y ago
My best guess would be that we use * for multiplication because x being alphanumeric is a valid variable name. regarding keyboard presence, this is one of the things that irks me about Mac keyboards is the absence of the # character. I write little programs and scripts on my mac infrequently enough that I have to look up how to type it every blasted time. That, and how to take screenshots. The "Print Scrn" key on PCs spoils me.
- Uncompetative 14y ago
  X = Y x Z B = T ^ F v T P = Q n R u S C = U cross V D = U dot V Area = Width by Height i.e. just capitalising names means that you can define macros that operate as infix operators: L . R -> L dot R L dot R -> Dot[L, R]
  - jewbacca 14y ago
    What language are you referring to? I'm not quite sure I understand your examples. -------- Related: In Haskell, any 2-argument function can be used (or defined) infix by surrounding it with backticks, eg: add 2 3 is equivalent to: 2 `add` 3 ---- And you can use this to cleanly write curried functions (often predicates) with their arguments flipped, eg: vowelCount = length . filter (`elem` "aeiou") ---- Note that functions named with punctuation characters are infix by default, and one can be used/defined prefix by surrounding it with brackets, eg: (<$>) = fmap toUpper <$> "aeiou" # => "AEIOU" ---- It's also convenient for resolving a subset of one of the harder problems in computer science: naming things. For a 2-argument function, use it infix and read it as a phrase in english. Which is clearer: ".jpg" `isSuffix` url or: ".jpg" `isSuffixOf` url You can also define functions' precedence and associativity (left/right) when used as an infix operator.