Regular expressions

GSL supports the use of regular expressions (regex).

Using regular expressions

You can apply regex patterns to various identifiers: atom names, residue names, group names, element names, element symbols, and labels.

  • Syntax:

    identifier r'<pattern>'

  • Examples:

    name r'^[1-9]?H.*'

    Selects all atoms with names matching the regex pattern (typically hydrogen atoms).

    resname r'^.*PC'

    Selects all residues with names ending in "PC".

    group r'^P'

    Selects all groups with names starting with 'P'.

Combining regular expressions with other identifiers

You can mix regex-based identifiers with standard identifiers in a single query.

  • Examples:

    name r'^C.*' and resname ALA GLY

    Selects atoms with names starting with 'C' in residues named ALA or GLY.

    name P r'^[1-9]?H.*'

    Selects atoms named 'P' and hydrogen atoms.

Syntax rules

  • Enclosure:
    The regex pattern must be enclosed within a "regular expression block" starting with r' and ending with '.

  • Case sensitivity:
    Regex patterns are case-sensitive unless specified otherwise within the pattern.

Supported regex features

GSL uses the regex crate for evaluating regular expressions. For detailed information on supported regex features, refer to the official documentation.