Inner functions

It is possible to use the following inner functions within other ContexQL functions that use String arguments, to enhance the flexibility of the queries with pattern matching functionality:

1. regex(pattern)

   • The function checks whether a match of a POSIX regular expression pattern occurs within a string.
   • In case a specific location in a string is needed, metacharacters ^ and $ can be used to bind to start and end of the string respectively.
   • Allows complex pattern matching based on regular expression syntax.
   • Example: @has_symbol(regex("MAX"))
     • This matches all objects that contain a symbol with a MAX substring in its name.
   tip

   This function can also be used to check the length of a string metadata entry. For example, the following code will check if the entry is at least 150 characters long:

   @match_object_meta($some_meta regex("^.{150,}$"))

   The upper limit of a bound in POSIX regex is 255, therefore if you need to enforce longer strings you need to repeat the matching block or multiply it.

2. iregex(pattern)

   • A case-insensitive version of regex.
   • Performs matching without regard to case differences.
   • Example: @has_name(iregex("\\.exe$"))
     • This matches all objects that have names ending with .exe, regardless of letter casing.

3. starts_with(prefix)

   • Matches values that start with the specified string prefix.
   • Useful for straightforward, prefix-based matching without the complexity of regular expressions.
   • Example:

     @match_object_meta($properties.application starts_with("Microsoft"))
     • This matches objects that have a $properties.application metadata key, and its value begins with Microsoft.

4. in statement

   • Checks if a given value belongs to a defined set.
   • Useful for matching against multiple different values.
   • Example:

     @has_name(in ("123.exe", iregex("invoice"))
     • This matches objects that have a name 123.exe or the name contains case-insensitive substring invoice.