Keyword Search Expressions

Keyword search expressions are used to specify a matching criteria for a keyword list. For any given keyword list, they evaluate to either true (matched) or false (unmatched).

The following syntax can be used for keyword search expressions:

expression

element [operator element [operator element [...]]]

element

keyword True if keyword exists in the list

"keyword" True if keyword exists in the list ¹

* True if keyword list is not empty

# True if keyword list contains at least one non-hidden keyword ²

(expression) True if expression is true

!element True if element is false

operator

& AND: True if both elements are true

| OR: True if either element is true (or both elements are true)

Operators are executed strictly from left to right. Expressions inside parentheses are always executed first.

¹ If a keyword contains one of the special characters above (*#()!&|), it should be enclosed in quotes ("").

² A hidden keyword is a keyword that begins with the underscore ( _ ) character.

Examples:

1. color Matches any keyword list that contains the keyword "color".

2. "b&w" Matches any keyword list that contains the keyword "b&w". "b&w" must be in quotes since "&" is an operator.

3. one|two|three Matches any keyword list that contains any or all of the keywords "one", "two", or "three".

4. one|two&!three Matches any keyword list that contains the keyword "one" and/or "two", but does not contain the keyword "three".

5. *&!two Matches any keyword list that contains at least one keyword, but does not contain the keyword "two".

6. (1|one)&(3|three) Matches any keyword list that contains the digit or word "one" and the digit or word "three".

Table of Contents

`expression`
	`element` [`operator` `element` [`operator` `element` [...]]]

`element`
	`keyword`	True if keyword exists in the list
	"`keyword`"	True if keyword exists in the list ¹
	*	True if keyword list is not empty
	#	True if keyword list contains at least one non-hidden keyword ²
	(`expression`)	True if expression is true
	!`element`	True if element is false

`operator`
	&	AND: True if both elements are true
	\|	OR: True if either element is true (or both elements are true)

1.	`color`	Matches any keyword list that contains the keyword "color".
2.	`"b&w"`	Matches any keyword list that contains the keyword "b&w". "b&w" must be in quotes since "&" is an operator.
3.	`one\|two\|three`	Matches any keyword list that contains any or all of the keywords "one", "two", or "three".
4.	`one\|two&!three`	Matches any keyword list that contains the keyword "one" and/or "two", but does not contain the keyword "three".
5.	`*&!two`	Matches any keyword list that contains at least one keyword, but does not contain the keyword "two".
6.	`(1\|one)&(3\|three)`	Matches any keyword list that contains the digit or word "one" and the digit or word "three".