0.9.0 2023-10-25

    - Handling square planar chirality.

0.8.6 2023-06-19

    - Implementing is_ring_atom().
    - No longer removing chiral centers from atoms in rings.
    - Accepting coloring subroutine references in
      is_unimportant_double_bond() and mark_all_double_bonds().
    - Returning false instead of undefined value.
    - Exporting %bond_order_to_symbol and %bond_symbol_to_order to simplify
      conversion between bond symbols and orders.

0.8.5 2023-01-26

    - Fixing incorrect chirality handling code as it did not consider all
      ring bonds up to now.

0.8.4 2022-11-29

    - Ceasing to mark unimportant double bonds in
      Chemistry::OpenSMILES::Stereo.

0.8.3 2022-11-03

    - Exporting %Chemistry::OpenSMILES::normal_valence.

0.8.2 2022-09-20

    - Adding Chemistry::OpenSMILES::Aromaticity and
      Chemistry::OpenSMILES::Stereo from smiles-scripts project v0.2.0.
    - Fixing prototypes of recently added functions.
    - Introducing Chemistry::OpenSMILES::is_double_bond().
    - Introducing Chemistry::OpenSMILES::is_ring_bond().

0.8.1 2022-05-11

    - Fixing a bug with incomplete cis/trans markers on ring bonds.
    - Introducing Chemistry::OpenSMILES::toggle_cistrans().
    - Introducing two functions for bond type determination.

0.8.0 2022-05-05

    - Implementing support for tetrahedral chiral centers having lone
      pairs.
    - Safeguarding against infinite cycles in
      Chemistry::OpenSMILES::Writer::_permutation_order().
    - Fixing mistake in Chemistry::OpenSMILES::Parser::parse()
      documentation.

0.7.0 2021-10-30

    - Fixing important issue with representing tetrahedral chiral centers
      by introducing 'chirality_neighbours' key to atom hashes.

0.6.0 2021-10-18

    - Allowing multi-digit hydrogen counts if enabled via parser option.
    - Standardizing chiral markers for allenal carbons.
    - Not standardizing chiral markers in raw output.
    - Reporting '@' and '@@' chiralities with other than 4 neighbours as
      they cannot be processed right now.

0.5.2 2021-10-11

    - Creating explicitly refvertexed Graph objects to get around all the
      problems caused by interpreting them as scalar values.

0.5.1 2021-08-29

    - Working around an incompatibility with Graph v0.9721.

0.5.0 2021-08-26

    - Handling raw parsing output in
      Chemistry::OpenSMILES::clean_chiral_centers().
    - Fixing a bug in position counting due to $1 pollution.
    - Detecting and reporting disconnected parts of moieties.
    - Introducing Chemistry::OpenSMILES::is_chiral() to detect both chiral
      atoms and moieties.
    - Fixing bug in Chemistry::OpenSMILES::clean_chiral_centers() which
      caused removal of all chiral centers, not just tetrahedral.
    - Introducing Chemistry::OpenSMILES::mirror() to invert chiral centers,
      currently only tetrahedral.
    - Fixing bug in printing of chiral centers, previously only tetrahedral
      centers were printed.

0.4.6 2021-04-14

    - Fixing reading/writing of cis/trans ring bonds.

0.4.5 2021-03-25

    - Fixing a bug in aromatic bond detection.

0.4.4 2021-03-09

    - Introducing Chemistry::OpenSMILES::clean_chiral_centers() to remove
      unnecessary tetrahedral chiral settings.

0.4.3 2021-01-25

    - Supporting tetrahedral chirality in
      Chemistry::OpenSMILES::Writer::write_SMILES().
    - Chiralities @TH1 and @TH2 are the same as @ and @@, respectively.
    - Specifying the requirement of Graph v0.97 or later.
    - Fixing issue with homepage.

0.4.2 2021-01-20

    - Exporting Chemistry::OpenSMILES::Writer::write_SMILES().
    - Removing chirality information from written SMILES, as code to
      write this reliably is not yet available.
    - Fixing writing of cis/trans bonds.

0.4.1 2021-01-12

    - Fixing an issue with 'scalar %hash' in t/01_atoms.t.
    - Listing a dependency on Graph::Traversal::DFS.

0.4.0 2021-01-11

    - Adding Chemistry::OpenSMILES::Writer, implementing a SMILES writer
      for the data structures built by Chemistry::OpenSMILES::Parser.
    - Converting 'charge' atom field to integer.
    - Exporting Chemistry::OpenSMILES::is_aromatic().

0.3.2 2020-10-05

    - Explicitly setting bond order to ':' on bonds between aromatic
      atoms.

0.3.1 2020-09-17

    - Establishing deterministic order while generating graph vertices
      for implicit hydrogen atoms.

0.3.0 2020-09-16

    - Deriving counts of implicit hydrogen atoms.
    - Default number of attached hydrogen atoms for atoms in square
      brackets is 0.
    - Supporting bracketless '*' atom.

0.2.1 2020-08-13

    - Adding 'number' atom field to store atom positions in the initial
      SMILES string.
    - Making 'class' atom field mandatory.
    - Making 'isotope' atom field an integer.

0.2.0 2020-05-20

    - Fixing an issue with graph merging.
    - Unifying the representation of single bonds.
    - Extending POD documentation.

0.1.3 2020-05-19

    - Detecting and reporting unbalanced parentheses.
    - Detecting and reporting unclosed ring bonds.
    - Fixing position pointers in error messages, removing line numbers.
    - Adding versioned dependency on Module::Build::Parse::Yapp v0.1.2.
    - Declaring minimum Perl version.
    - Fixing the POD.

0.1.2 2020-05-17

    - Turning hydrogen counts into real vertices. If 'raw' option is
      present, hydrogen counts are left as integers instead.

0.1.1 2020-05-14

    - Adding missing dependency on Graph::Undirected.
    - Adding POD.

0.1.0 2020-05-13

    - Initial release.