Advanced Searches in emplode v2.0

2001-10-25 19:29:00 +0000

emplode v2.0 adds the ability to search your music database. It provides two methods of doing this: simple searches (which are hopefully so simple that I won’t explain them here), and advanced searches.

Syntax

search  ::= conj [or conj]*
conj    ::= term [and term]*
term    ::= item [relop item]
item    ::= literal | tag | "(" search ")" | not item
literal ::= dquote-char (alpha|numeric|punctuation)* dquote-char
          | numeric+
          | "true" | "false"
tag     ::= alpha*

Tags

Essentially, anything that appears in a *1 file is fine. We also allow the following pseudo-tags:

Some of them return time_t values, which aren’t terribly useful. We’ll come up with a way to express these for matching later.

Boolean Values

“true” and “false” are valid values. They evaluate as you’d expect. Strings evaluate to false if empty, true otherwise.

Case-sensitivity

String comparisons are case-insensitive. Tag names are case-insensitive, except for the pseudo-tags. This is a bug.