precedence lossage

/pre's*-dens los'*j/ A misunderstanding of operator precedence resulting in unintended grouping of arithmetic or logical operators when coding an expression. Used especially of mistakes in C code due to the nonintuitively low precedence of "&", "|", "^", "<<" and ">>". For example, the following C expression, intended to test the least significant bit of x,

	x & 1 == 0

is parsed as

	x & (1 == 0)

which is always zero (false).

Some lazy programmers ignore precedence and parenthesise everything. Lisp fans enjoy pointing out that this can't happen in *their* favourite language, which eschews precedence entirely, requiring one to use explicit parentheses everywhere.

[Jargon File]

Last updated: 1994-12-16

Try this search on Wikipedia, OneLook, Google

Nearby terms: PRE-CC « PRECCX « precedence « precedence lossage » precharge » precision » predecessor


Loading

Copyright Denis Howe 1985

directoryold.com. General Business Directory. http://hotbookee.com.