5 ms·

This is a beautiful way to express multiple ?: expressions.

by beobab 7y ago

kazinator 7y ago
I don't agree. It occludes the nested structure. We can regard the condition as the head of a clause, and the ? and : as heads of sub-clauses: A ? B : C which leads to: return a < b ? -1 : a > b ? 1 : 0;
- atq2119 7y ago
  What you're writing here is equivalent to insisting that people do: if (a < b) { return -1; } else { if (a > b) { return 1; } else { return 0; } }
  - deleted 7y ago
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  - kazinator 7y ago
    Nope, since I haven't added any non-whitespace characters, rather it is like insisting that people do: if (a < b) { return -1; } else if (a > b) { return 1; } else { return 0; } Unlike your perfectly formatted code there, this has a bit of a visual problem: a one-liner consequent is fully braced, whereas a multi-line alternative isn't. Ternary operators are different. They have confusing nesting and do not support the equivalent of the "if/else ladder" pattern very well.
- naasking 7y ago
  > It occludes the nested structure. The nesting is irrelevant to understanding the semantics, so this objection doesn't fly. The idiom is basically just a truth table with conditions on the left and the matching value on the right. You read it left-to-right, top-to-bottom, just like all other code. The first condition on the left that matches returns the value on right-hand side.
  - kazinator 7y ago
    > The nesting is irrelevant to understanding the semantics The nesting is absolutely relevant to producing the semantics. The following uses deceptive whitespace to suggest a nesting that is contrary to the actual nesting, interfering with understanding: if (foo) if (bar) xyzzy(); else flop(); The ternary operator A ? B : C is the goofy invention of demented mind. In nested situations, it is mind-bendingly unreadable. It behooves us to style it in a way that reveals the abstract syntax tree structure. In C, I would in fact recommend: #define if3(a, b, c) ((a) ? (c) : (c)) return if3(a < b, -1, if3(a > b, 1, 0)); Now we can have it in one line, yet it's clear.
    - naasking 7y ago
      > The following uses deceptive whitespace to suggest a nesting that is contrary to the actual nesting, interfering with understanding Fortunately, the ternary pattern doesn't exhibit this problem. So again, this objection doesn't fly.

This is a beautiful way to express multiple ?: expressions.

by beobab 7y ago

This is a beautiful way to express multiple ?: expressions.

I don't agree. It occludes the nested structure. We can regard the condition as the head of a clause, and the ? and : as heads of sub-clauses: A ? B : C which leads to: return a < b ? -1 : a > b ? 1 : 0;

atq2119 7y ago
What you're writing here is equivalent to insisting that people do: if (a < b) { return -1; } else { if (a > b) { return 1; } else { return 0; } }
- deleted 7y ago
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- deleted 7y ago
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- kazinator 7y ago
  Nope, since I haven't added any non-whitespace characters, rather it is like insisting that people do: if (a < b) { return -1; } else if (a > b) { return 1; } else { return 0; } Unlike your perfectly formatted code there, this has a bit of a visual problem: a one-liner consequent is fully braced, whereas a multi-line alternative isn't. Ternary operators are different. They have confusing nesting and do not support the equivalent of the "if/else ladder" pattern very well.
naasking 7y ago
> It occludes the nested structure. The nesting is irrelevant to understanding the semantics, so this objection doesn't fly. The idiom is basically just a truth table with conditions on the left and the matching value on the right. You read it left-to-right, top-to-bottom, just like all other code. The first condition on the left that matches returns the value on right-hand side.
- kazinator 7y ago
  > The nesting is irrelevant to understanding the semantics The nesting is absolutely relevant to producing the semantics. The following uses deceptive whitespace to suggest a nesting that is contrary to the actual nesting, interfering with understanding: if (foo) if (bar) xyzzy(); else flop(); The ternary operator A ? B : C is the goofy invention of demented mind. In nested situations, it is mind-bendingly unreadable. It behooves us to style it in a way that reveals the abstract syntax tree structure. In C, I would in fact recommend: #define if3(a, b, c) ((a) ? (c) : (c)) return if3(a < b, -1, if3(a > b, 1, 0)); Now we can have it in one line, yet it's clear.
  - naasking 7y ago
    > The following uses deceptive whitespace to suggest a nesting that is contrary to the actual nesting, interfering with understanding Fortunately, the ternary pattern doesn't exhibit this problem. So again, this objection doesn't fly.