I've written a static code analyzer for C/C++ code. The javascript operator precedence table is almost the same as the C/C++ operator precedence table. So I was pleasantly surprised when I could also run the script on javascript code and have reasonable errors reported as well.
One bug that appeared is bitwise-AND followed by a comparison with no parentheses grouping the bitwise-AND operation. Obviously developers thought the bitwise-AND had higher precedence than the comparison. They were wrong. They obviously didn't test the code either.
Javascript code doesn't twiddle bits as often as C/C++ code so this bug doesn't appear as often.
For text editor support of this problem, what may work is to show that an expression with higher precedence IS evaluated first before the expression using an operator lower on the operator precedence table.
There was a suggestion in the Vim mailing list years ago to use background color to show the nesting depth of a block.
One could use background color or a font attribute, say underline or font-size, to indicate the evaluation order of a non-parenthesized multi-operator expression.
HN posts only support italics for font formatting so I'll use that in my example - hmmm, looks like I can't use block formatting in addition - just imagine the code indented in a fixed-width font
One bug that appeared is bitwise-AND followed by a comparison with no parentheses grouping the bitwise-AND operation. Obviously developers thought the bitwise-AND had higher precedence than the comparison. They were wrong. They obviously didn't test the code either.
Javascript code doesn't twiddle bits as often as C/C++ code so this bug doesn't appear as often.
For text editor support of this problem, what may work is to show that an expression with higher precedence IS evaluated first before the expression using an operator lower on the operator precedence table.
There was a suggestion in the Vim mailing list years ago to use background color to show the nesting depth of a block.
One could use background color or a font attribute, say underline or font-size, to indicate the evaluation order of a non-parenthesized multi-operator expression.
HN posts only support italics for font formatting so I'll use that in my example - hmmm, looks like I can't use block formatting in addition - just imagine the code indented in a fixed-width font
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if (x & 3 == 1) { // do something }
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