Equality in Julia is tested using == x = 5 if x == 5 println("x is five!") end However, a mistake I make all the time, even several times a day, over a period of several years, is to use = instead of == : x = 5 if x = 5 # error println("x is five!") end Recent Example 1: I was writing some J…

Some languages do that – the interpretation of = depends on context.

[image] viraltux: I wonder, couldn’t the compiler decide the context if we use = for assignments and bool comparisons? But how would the compiler know whether the user deliberately used assignment, or intended to use comparison, but misspelled it? [image] viraltux: One might think that a…

[image] DNF: Multiple dispatch has to do with the types used, not with the context. In a wide sense the type is also “context”, a==b has a boolean type, which provides context in this sense. [image] DNF: But how would the compiler know whether the user deliberately used assignment, or in…

[image] viraltux: In a wide sense the type is also “context”, a==b has a boolean type, which provides context in this sense. But you are not talking about deciding this based on types, as far as I can tell. Types are a kind of context, but context is not a kind of type. [image] viraltux: …

[image] DNF: if (x = a) would be bad, because the user could intend this exact thing, and it makes sense to do, even if it’s less common. I think this case is already handled by context in Julia when not a bool: julia> if (x=a) print(1) end ERROR: TypeError: non-boolean (Int6…

What would the context of if (a=b) < 5 then be? VBA does what you are proposing (it uses = for assignment and for equality checking), but it’s syntax is very poor and constrained. You can special-case all the places where one choice is made over the other, but that just makes things inconsistent a…

If we go down the path of actually just using = then we need to agree on some convention to break ambiguities. For instance, let’s agree that in a Boolean context = is always an equality test, and in your example [image] heetbeet: if (a=b) < 5 (a=b) would be an equality test, and if we meant…

At what point does the cognitive load of interpreting what = might mean in whatever context become greater than simply remembering and applying different operators, however they may look? It is arguably easier (and more efficient) for humans to parse different symbols. Then, this discussion becomes…

Irrespective of how good or bad == is (I’m pro), please never write if (flag = booleanfunction()). Even if it’s intentional, you are just making the code harder to interpret. For what, a single line less of code? Why don’t we just go back to the C hacks like while(*a++ = *b++)? Contrary to popular b…

[image] doit: I would love to use ** instead of ^ Wooow, what? That’s interesting. Would you mind explaining? I always found this to be one of the most bizarre things in python. The ^ is almost universally used as the superscript/exponentiation symbol, to the point where I’m pretty sure most…

My Brain Is Hard-Wired Against ==; Help Me, Julia

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blackeneth July 5, 2021, 1:38am 101

It is explained here

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My Brain Is Hard-Wired Against ==; Help Me, Julia

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