2 Debian Code Search: An Overview

4 Search result quality
Query is a library symbol When the query matches one of the library’s exported function
symbols, the package should get a much higher ranking. This is computationally cheap
but works only for C-like programming languages and libraries.
Query is in the package’s description The package description is a concise summary
of what the package does. Library packages often list their main areas or available
functions, so it is likely that the user’s search query matches the description, especially
if she is searching for an algorithm name.
4.2.3 Ranking factors which depend on the actual results
Indentation level of the result The vast majority of programming languages represents
different scopes by indentation 3 . Scopes represent a hierarchy: higher scopes mean
the symbol is more important (e.g. a function definition at the top-level scope in C
is more important than a variable declaration in a lower-level scope). To quickly and
language-independently decide whether one line is more important than another, the
amount of whitespace in front of it is counted.
Word boundary match To prefer more exact results, the regular expression features \b
can be used (match on word boundaries). As an example, \bXCreateWindow\b will
match Window XCreateWindow( but not register XCreateWindowEvent *ev = .
Since the position of the matching portion of text is known, it is used to further prefer
earlier matches over later matches.
Since programming languages are structured from left-to-right, earlier matches (such as
function definitions) are better than later matches (such as function parameter types).
3 Of the most popular languages in Debian, the first 10 (C, Perl, C++, Python, Java, Ruby, ocaml, LISP, Shell,
PHP, see section 4.6 (page 44)) use indentation.
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