YAML itself does not define a way to store coordinate systems or transformations - such definitions
must be provided by a suitable WCS-oriented schema. The scheme to use is defined by the
YamlEncoding attribute. Currently, the only schema supported by this class is
" , defined by
the Space Telescope Science Institute. (see http://asdf-standard.readthedocs.io). At some point in the
future support will be added for the AST NATIVE scheme.
Normally, when you use a YamlChan, you should provide
" routines which
connect it to an external data store by reading and writing the resulting text. These routines should
perform any conversions needed between external character encodings and the internal ASCII
encoding. If no such routines are supplied, a Channel will read from standard input and write to
This class uses the limyaml library to read and write yaml. If the libyaml library cannot be found when the AST library is configured, then an error will be reported if any YamlChan methods are invoked.