Dennis Ritchie’s first C compiler (c. 1972)

Re:Dennis Ritchie’s first C compiler (c. 1972) by colejohnson66 on Thursday March 11, 2021 @05:59PM (#26430106)

Is there an explanation on why C’s operator precedence is weird? Such as: why does the bitwise AND have higher precedence than logical AND?

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Re:Dennis Ritchie’s first C compiler (c. 1972) by compiler-guy on Friday March 12, 2021 @05:41PM (#26441847)

There is, and it is amusing

“In retrospect it would have been better to go ahead and change the precedence of & to higher than ==, but it seemed safer just to split & and && without moving & past an existing operator. (After all, we had several hundred kilobytes of source code, and maybe 3 installations....)“

https://www.lysator.liu.se/c/dmr-on-or.html

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Re:Dennis Ritchie’s first C compiler (c. 1972) by briantakita on Friday March 12, 2021 @03:27PM (#26440481)

> why does the bitwise AND have higher precedence than logical AND?

Why is this precedence weird? Bitwise AND tends to be used to transform data while a logical AND tends to be used for control flow.

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Re:Dennis Ritchie’s first C compiler (c. 1972) by colejohnson66 on Friday March 12, 2021 @03:42PM (#26440634)

I meant equals having a higher precedence than bitwise AND.

As in:

    if (x & 2 == 2)

...is actually parsed as:

    if (x & (2 == 2))

...which isn’t intuitive.

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Re:Dennis Ritchie’s first C compiler (c. 1972) by compiler-guy on Friday March 12, 2021 @05:42PM (#26441853)

See the above example from dmr himself

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