4 ms·

> (though it would have been better if single characters would have been used for McCarthy operators and double characters for the bit string operators) (It pr

by a1369209993 4y ago

> (though it would have been better if single characters would have been used for McCarthy operators and double characters for the bit string operators) (It probably is better on net, but) not as much as one might think, actually. It's a clear win in terms of Huffman coding, but there's also a general principle that small infix operators have higher precedence, and large ones lower precedence, like how multiplication in math notation uses "·", or more often nothing at all, while addition uses "+". (It also shows up in natural languages; consider "Tom and Dick and Harry as well as Alice and Bob".) It's (probably, usually) worth subverting for assignment, because "=" is used a lot, but I'm not sure if it's a good tradeoff for boolean operators, eg: if(x == 3 & y == 5) foo(); // look's a bit too much like it's saying if(x == (3&y) == 5) foo(); // ie (x==(3&y)) & ((3&y)==5), rather than if((x==3) & (y==5)) foo(); Though, like "=", the initial misleading hueristic might wear off with sufficient exposure, and you can usually fudge it by adding spaces around the low-precedence operator.

adrian_b 4y ago
Your examples would have looked much better and without suggestions of wrong precedence if C would not have also replaced the Algol operators ":=" and "=" with "=" and "==". In my opinion this is one of the greatest mistakes of C, and which unfortunately has been inherited by too many other languages. Even Dennis Ritchie has admitted that this might have not been a good idea.
- Tozen 4y ago
  Agree.
- a1369209993 4y ago
  > if C would not have also replaced the Algol operators ":=" and "=" with "=" and "==". That wouldn't help "!=" and "<=", and "=" is used far too often (in typical code, hence the "(probably, usually)" above) to be multi-character.
  - adrian_b 4y ago
    That is due to the limitation of the source code to ASCII, which I consider obsolete. "!=", "<=" and the like were single-character operators in Algol and in many other early programming languages. They have been replaced with 2-character operators only because IBM and most other important US computer manufacturers were not willing to support character sets with enough characters for covering the needs of mathematics and of other languages than English. The target for the US character sets was only the text that may appear in commercial letters written in English. For any other uses, like programming languages, characters have been accepted only when they could occupy one of the few vacant places in the character map. The dominance of the US-made computer hardware forced this ugly limitation upon the programming languages. So the programming languages had to use various commercial characters, e.g. !, @, #, $, %, instead of more appropriate traditional mathematical symbols. Now, with Unicode and UTF-8, I consider the use of ASCII for source code as stupid. In Unicode, also the ":=" of Algol exists as a single character. Regardless of how operators are encoded, as single- or multiple-characters, a good text editor for source code allows one to change the correspondence between pressed keys and the inserted text. Because assignment is used more frequently, even when using ASCII a text editor can be configured to insert ":=" when you press "=", and, for example, to insert "=" for ctrl-= and "!=" for alt-=, in order to minimize key presses.
    - zozbot234 4y ago
      Many early programming languages were even more limited than ASCII itself, for the sake of portability. In Algol itself the operators and keywords were defined as abstract representations, with multiple possible ways of serializing those to computer-encoded text.

adrian_b 4y ago

Your examples would have looked much better and without suggestions of wrong precedence if C would not have also replaced the Algol operators ":=" and "=" with "=" and "==". In my opinion this is one of the greatest mistakes of C, and which unfortunately has been inherited by too many other languages. Even Dennis Ritchie has admitted that this might have not been a good idea.

Tozen 4y ago
Agree.
a1369209993 4y ago
> if C would not have also replaced the Algol operators ":=" and "=" with "=" and "==". That wouldn't help "!=" and "<=", and "=" is used far too often (in typical code, hence the "(probably, usually)" above) to be multi-character.
- adrian_b 4y ago
  That is due to the limitation of the source code to ASCII, which I consider obsolete. "!=", "<=" and the like were single-character operators in Algol and in many other early programming languages. They have been replaced with 2-character operators only because IBM and most other important US computer manufacturers were not willing to support character sets with enough characters for covering the needs of mathematics and of other languages than English. The target for the US character sets was only the text that may appear in commercial letters written in English. For any other uses, like programming languages, characters have been accepted only when they could occupy one of the few vacant places in the character map. The dominance of the US-made computer hardware forced this ugly limitation upon the programming languages. So the programming languages had to use various commercial characters, e.g. !, @, #, $, %, instead of more appropriate traditional mathematical symbols. Now, with Unicode and UTF-8, I consider the use of ASCII for source code as stupid. In Unicode, also the ":=" of Algol exists as a single character. Regardless of how operators are encoded, as single- or multiple-characters, a good text editor for source code allows one to change the correspondence between pressed keys and the inserted text. Because assignment is used more frequently, even when using ASCII a text editor can be configured to insert ":=" when you press "=", and, for example, to insert "=" for ctrl-= and "!=" for alt-=, in order to minimize key presses.
  - zozbot234 4y ago
    Many early programming languages were even more limited than ASCII itself, for the sake of portability. In Algol itself the operators and keywords were defined as abstract representations, with multiple possible ways of serializing those to computer-encoded text.