=====================================================================
Version 1.5.1 - Sixth release on CRAN
=====================================================================

BUG FIXES:
- loadSNOMED would overwrite different versions of tables loaded from
  the same folder so some tables would not be loaded. This is now fixed

CHANGES:
- The CDB generation function can now include UMLS concepts
- Wordnet and manual synonyms tables that were used to generate a CDB
  are now included within it
- default set of acceptable provenance values changed to 0 (accurate
  maps only) for adding inactive concepts using the HISTORY table 
- addInactiveConcepts allows filtering on the ISAMBIGUOUS column of
  the HISTORY table
- ICD-10 and OPCS4 mapping algorithm is modified - now it returns the
  highest priority number map within each map group and block, as 
  this is more likely to correspond accurately to the SNOMED CT concept
- Additional files exported by exportMiADECDB to correspond with the
  new version of MiADE

=====================================================================
Version 1.5.0
=====================================================================

BUG FIXES:
- Changes to data.table equality tests to correct CRAN errors

CHANGES:
- The 'decompose' function now also checks for laterality not
  associated with a body structure
- The 'compose' function returns an exact match if possible

=====================================================================
Version 1.4.0 - Fifth release on CRAN
=====================================================================

BUG FIXES:
- Bug fixes in createCDB, decompose and compose
- Previous version required data.table >= 1.14.3 but this was not listed
  as a dependency, now it works with data.table >= 1.12.8
- Modifications to display of filenames in loadSNOMED messages to
  correct CRAN errors in Windows build

NEW FEATURES:
- Option to omit metadata in codelist export

CHANGES:
- New function addComposeLookupToCDB replaces createComposeLookup to
  add the composition lookup table to the CDB. The composition lookup
  table no longer needs to be supplied as a separate argument to compose
- Performance improvements for decompose and relatedConcepts

=====================================================================
Version 1.3 - Fourth release on CRAN
=====================================================================

BUG FIXES:
- Ensure that 'description' returns a 'type' column if there are 0 rows
  and include_synonyms = TRUE
- Ensure that 'description' returns only one Fully Specified Name per
  concept, and 'semanticType' returns only a single result per concept

NEW FEATURES:
- New function 'createTransitive' to generate a transitive closure
  table containing all ancestor-descendant pairs. This makes
  subsequent ancestor / descendant searches quicker
- Revised ancestor and descendant functions to be able to use a
  transitive closure table
- New function 'addInactiveConcepts' to add inactive concepts to
  codelists, using the history and query tables
- New functions 'createCDB' and 'createMiADECDB' to generate a
  concept database and lookups for named entity recognition
- New function 'createDisambiguationTrainer' to use longer SNOMED CT
  terms to create texts to help train disambiguation of short terms.
- New functions 'decompose', 'batchDecompose' and 'createComposeLookup'
  to create a lookup table for composition of SNOMED CT concepts
- New function 'compose' to select a detailed SNOMED CT concept
  based on a general concept and separate concepts for attributes such
  as body site

=====================================================================
Version 1.2 - Third release on CRAN
=====================================================================

BUG FIXES:
- as.integer64.SNOMEDconcept now allows additional optional arguments,
  like the generic as.integer64 function

NEW FEATURES:
- loadSNOMED also optionally loads history and query tables from a
  SNOMED CT distribution
- New function addInactiveConcepts to add inactive concepts to
  codelists, using the history and query tables

=====================================================================
Version 1.1
=====================================================================

BUG FIXES:
- Showing a concept description caused an error if there were
  multiple descriptions for a concept and duplicate concepts in the
  SNOMEDconcept vector
- SNOMEDcodelist timestamps were set to the user-supplied date instead
  of the system time
- Error on exporting SNOMEDcodelists with single row maps that had NULL
  values. Instead the NULLs are now zero-length character vectors, which
  can be exported correctly with fwrite.
- Ensure that SNOMED environment is passed from htmlCodelistHierarchy
  to showCodelistHierarchy
- Corrected bug in hasAttribute when SNOMED RELATIONSHIP table contains
  duplicate source-type-destination triples (e.g. if some are inactive)

CHANGES:
- New vignette 'customHierarchy.Rmd' explaining how to create a custom
  SNOMED-like database to enable the hierarchical view
- Vignette shows how to obtain 'History of' terms for phenotyping
  algorithms

=====================================================================
Version 1.0 - Second release on CRAN
=====================================================================

NEW FEATURES:
- New getMaps function to map a codelist to another terminology
  system
- New htmlCodelistHierarchy function to create an interactive HTML
  file to explore a codelist
- SNOMED CT simple reference sets included in the SNOMED environment,
  with new function getRefset
- Function to load a mapping table from the NHS Digital data
  migration pack (loadREADMAPS), for mapping to Read V2 and CTV3

CHANGES:
- SNOMEDcodelist S3 data type has been redesigned to include metadata
  as well as accommodate different formats of codelists
- SNOMEDcodelist no longer includes descendants by default
- SNOMED environment now includes mapping tables and simple refsets
- Updated method of displaying SNOMED CT codelists

=====================================================================
Version 0.2 - Initial release on CRAN
=====================================================================

- Initial release