Building a C Compiler Type System – Part 1: The Formidable Declarator

Re:Building a C Compiler Type System – Part 1: The Formidabl... by jotux on Thursday July 07, 2016 @03:20PM (#12051529)

C's comma operator syntax is also weird and, in my experience, many people don't really understand it that well.

edit: In reference to the last line: "oh this was a stupid idea, let's not take advantage of it".

It's a weird feature that generally makes the code more difficult to understand but people still use it a lot, similar to multiple declarations on a single line with pointers mixed in.

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Re:Building a C Compiler Type System – Part 1: The Formidabl... by bluetomcat on Thursday July 07, 2016 @03:53PM (#12051689)

The comma acts as a separator in declarations, function calls and initializers.

In ordinary expressions it is a normal binary operator (just like / or &&), but has the lowest precedence and simply evaluates the left-hand side, discarding the result, then (in that order) evaluates the right-hand side, returning its value as the result.

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Re:Building a C Compiler Type System – Part 1: The Formidabl... by penguinduck on Thursday July 07, 2016 @03:45PM (#12051652)

Maybe you don't understand it that well because the described usage of a comma is not a comma operator (or any kind of operator).

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Re:Building a C Compiler Type System – Part 1: The Formidabl... by imtringued on Friday July 08, 2016 @01:26AM (#12053686)

https://en.wikipedia.org/wiki/Comma_operator

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Re:Building a C Compiler Type System – Part 1: The Formidabl... by penguinduck on Friday July 08, 2016 @01:54AM (#12053778)

Your point? The multiple declaration syntax which is being discussed here uses comma separators, not operators.

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