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Keyword expression syntax

MiaRec supports very powerful expression syntax for matching keywords / phrases in text.

The following operators are supported:

  • AND
  • OR
  • &
  • |
  • NOT
  • NOTIN
  • NEAR
  • NOTNEAR
  • ONEAR
  • MATCHES

Additionally, it supports:

  • parentheses "(" and ")" for grouping.
  • Wildcard

Boolean operators (AND, OR, NOT, & and |)

Expression Description
quick OR brown matches "quick fox" and "brown fox"
quick AND fox matches "quick fox"
NOT brown AND fox matches "quick fox" but not "brown fox"

Synonyms & and I

Symbols & and | are synonyms to AND and OR respectively.

Expression Equivalent form
quick | brown quick OR brown
quick & fox quick AND fox
(quick | brown | grey ) & fox (quick OR brown OR grey) AND fox

When using | and & symbols, a space charter between words is optional. The following are valid expressions:

  • (quick | brown | grey ) & fox
  • (quick|brown|grey)&fox

Case in operator names

A case in operator name is important. AND is treated as an operator, while and is treated literally as a word and in text "what a beautiful and amazing day".

Order of term match

An order of matched words is not taken into account. If an order is important, then use ONEAR operator.

Expression Description
quick AND fox matches both "quick fox" and "fox quick"

Distance between matched words

A distance between words is not taken into account. Use operators quoted term or NEAR, ONEAR and NOTNEAR if a distance is important.

Expression Description
quick AND fox matches both "quick fox" and "quick dog was chasing a fox"
"quick fox" matches "dog was chasing a quick fox" bot not "quick dog was chasing a fox"
quick NEAR:3 fox matches "quick fox" and "quick and cute fox" but not "quick dog was chasing a fox", because of a distance between quick and fox words is more than 3 words.

Quoted term

Use quotes (") to search for an exact phrase.

Expression Description
"quick fox" matches "dog was chasing a quick fox" bot not "quick dog was chasing a fox"
quick fox matches both "quick fox" and "quick dog was chasing a fox", because of such expression is equivalent to "quick NEAR:5 fox", i.e. words quick and fox can be found up to 5 words in distance between each other.

Wildcards

A wildcard character is used to substitute one or more characters in a string.

Supported wildcard characters:

Symbol Description Example
* Represents zero or more characters bl* finds bl, black, blue, and blob
? Represents a single character h?t finds hot, hat, and hit
[ ] Represents any single character within the brackets h[oa]t finds hot and hat, but not hit
! Represents any character not in the brackets h[!oa]t finds hit, but not hot and hat
- Represents a range of characters c[a-b]t finds cat and cbt

To use one wildcard characters literally, escape it with \ symbol. For example yes\! expression will find yes! text.

Grouping

Multiple terms or clauses can be grouped together with parentheses, to form sub-queries:

Examples:

  • (quick OR brown) AND fox
  • (quick | brown | grey) fox
  • NOT brown AND (fox OR dog)

Proximity operators (NEAR, ONEAR, NOTNEAR, NOTIN)

Proximity operators allow you to locate one searched term within a certain distance of another.

NEAR[:x]

Finds the phrase where the terms joined by the operator are within the specified number of words of each other. \ Where x is a maximum distance between the searched terms.

Note 1. A distance parameter is optional. If omitted, a default distance of 5 is used, i.e. NEAR is equivalent to NEAR:5

Note 2. An order of the found terms is not taken into account, i.e. brown NEAR fox will match both "dog is chasing brown fox" and "fox is chasing brown dog".

Note 3. When chaining multiple operators, then parentheses must be used when a distance is not the same. For example, expressions brown NEAR quick NEAR fox and brown NEAR:2 quick NEAR:2 fox are both valid, but brown NEAR:2 quick NEAR:5 fox is not valid because a distance is 2 in one case and 5 in another. Parentheses must be added to make such expression valid: (brown NEAR:2 quick) NEAR:5 fox

Expression Description
cancel* NEAR order Matches "cancel my order", "order is cancelled", but not "cancel my account and then place an order", because of a distance between cancel and order in the last example is more than default 5 words.
cancel* NEAR:1 order Matches "cancel order", but not "cancel my order" because of distance between words is more than requested (1).
brown NEAR quick NEAR fox Matches "brown and quick fox", but not "brown fox"

ONEAR[:x]

Similar to NEAR operator, but an order of the matched terms is taken into account. For example brown NEAR fox will match "brown fox" but not "fox brown".

Expression Description
cancel* ONEAR order Matches "cancel my order" but not "order is cancelled", because of the order of terms is important.

Note 1. A distance parameter is optional. If omitted, a default distance of 5 is used, i.e. ONEAR is equivalent to ONEAR:5

Note 2. When chaining multiple operators, then parentheses must be used when a distance is not the same. For example, expressions brown ONEAR quick ONEAR fox and brown ONEAR:2 quick ONEAR:2 fox are both valid, but brown ONEAR:2 quick ONEAR:5 fox is not valid because a distance is 2 in one case and 5 in another. Parentheses must be added to make such expression valid: (brown ONEAR:2 quick) ONEAR:5 fox

NOTNEAR[:x]

Syntax:

<term-1> NOTNEAR[:x] <term-2>

Operator NOTNEAR finds the term on the left side of the operator (\) that is not in close proximity to the term on the right side of operator (\).

Expression Description
cancel* NOTNEAR account Matches "cancel order", "order is cancelled", but neither "cancel my account" not "this account is cancelled".
cancel* NOTNEAR:1 account Matches "cancel my bank account" but not "cancel account", because of a required distance between terms is maximum 1.

Note 1. A distance parameter is optional. If omitted, a default distance of 5 is used, i.e. NOTNEAR is equivalent to NOTNEAR:5

Note 2. An order of the found terms is not taken into account, i.e. cancel* NOTNEAR account will exclude both "cancel account" and "account canceled"

Note 3. A chaining of operator NOTNEAR is not supported. Use parentheses to specifically group multiple expressions. For example, cancel* NOTNEAR bank* NOTNEAR account must be rewritten as cancel* NOTNEAR (bank* NOTNEAR account)

NOTIN

Operator NOTIN allows to match terms that are not part of a longer term. For example, you would like to find word "problem", but not when it is part of phrase "not a problem".

Examples:

  • problem NOTIN "not a problem"
  • problem NOTIN "no problem"
  • problem NOTIN ((no|not) ONEAR problem)
  • problem NOTIN no* ONEAR:2 problem

Count occurrences (MATCHES)

Operator MATCHES finds the term, that occurs the requested number of times in a text. For example, it can be used to find phrase where at least 8 digits are spoken.

Syntax:

<term> MATCHES: N[-M]

Where:

  • \ is a search expression, which can be a word, phrase or a complex expression like (brown | quick)
  • N is a minimum number of occurrences of the term in the text
  • M is a maximum number of occurrences of the term in the text. If omitted, then maximum M is equal to N, i.e brown MATCHES: 2 is the same as brown MATCHES: 2-2
Expression Description
(one|two|three|four|five|six|seven|eight|nine|ten) MATCHES: 5-10 Matches "one two two four five seven" but not "one two"

Precedence rules

When no parentheses are present, then the operators are evaluated in the following order:

  • NOTNEAR
  • ONEAR
  • NEAR
  • NOTIN
  • MATCHES
  • NOT
  • AND
  • OR
Expression Equivalent form
quick OR brown AND fox quick OR (brown AND fox)
quick NEAR brown AND fox (quick NEAR brown) AND fox

Default operator

If no operator is included between terms, then a default NEAR operator is used:

Expression Equivalent form
brown fox brown NEAR fox
(quick OR brown) fox (quick OR brown) NEAR fox
quick OR brown fox quick OR (brown NEAR fox)

Note, NEAR operator has a higher priority than OR and AND (see Precedence rules section).

Combining operators

Multiple operators can be combined together to form a complex expression.

Expression Description
cancel* NEAR (order|account) matches "cancel order", "order is cancelled", "I am cancelling my account", "I want to cancel this order"
definitely NOTIN "definitely not" matches "