[Input] rename --id to --phase in ck2yaml options

The option --phase is consistent with the resulting yaml entry in 'phases'.
The --id option is still supported, with a warning being issued.

include/cantera/base/SolutionBase.h

@@ -78,18 +78,18 @@ public:
     void setTransport(shared_ptr<Transport> transport);
 
     //! Accessor for the ThermoPhase object
-    shared_ptr<ThermoPhase> thermo() {
-        return m_thermo;
+    ThermoPhase& thermo() {
+        return *m_thermo;
     }
 
     //! Accessor for the Kinetics object
-    shared_ptr<Kinetics> kinetics() {
-        return m_kinetics;
+    Kinetics& kinetics() {
+        return *m_kinetics;
     }
 
     //! Accessor for the Transport object
-    shared_ptr<Transport> transport() {
-        return m_transport;
+    Transport& transport() {
+        return *m_transport;
     }
 
 protected:

interfaces/cython/cantera/ck2yaml.py

@@ -12,7 +12,7 @@ Usage:
             [--thermo=<filename>]
             [--transport=<filename>]
             [--surface=<filename>]
-            [--id=<phase-id>]
+            [--phase=<phasename>]
             [--output=<filename>]
             [--permissive]
             [-d | --debug]
@@ -32,7 +32,8 @@ specified as 'input' and the surface phase input file should be specified as
 'surface'.
 
 The '--permissive' option allows certain recoverable parsing errors (e.g.
-duplicate transport data) to be ignored.
+duplicate transport data) to be ignored. The '--phase=<phasename>' option
+is used to override default phase names (i.e. 'gas').
 """
 
 from collections import defaultdict, OrderedDict
@@ -1797,7 +1798,7 @@ class Parser:
             if speciesName in self.species_dict:
                 if len(data) != 7:
                     raise InputError('Unable to parse line {} of {}:\n"""\n{}"""\n'
-                        '6 transport parameters expected, but found {}.', 
+                        '6 transport parameters expected, but found {}.',
                             line_offset + i, filename, original_line, len(data)-1)
 
                 if self.species_dict[speciesName].transport is None:
@@ -2024,9 +2025,9 @@ def convert_mech(input_file, thermo_file=None, transport_file=None, surface_file
 
 def main(argv):
 
-    longOptions = ['input=', 'thermo=', 'transport=', 'surface=', 'id=',
+    longOptions = ['input=', 'thermo=', 'transport=', 'surface=', 'phase=',
                    'output=', 'permissive', 'help', 'debug', 'quiet',
-                   'no-validate']
+                   'no-validate', 'id=']
 
     try:
         optlist, args = getopt.getopt(argv, 'dh', longOptions)
@@ -2054,7 +2055,13 @@ def main(argv):
     quiet = '--quiet' in options
     transport_file = options.get('--transport')
     surface_file = options.get('--surface')
-    phase_name = options.get('--id', 'gas')
+
+    if '--id' in options:
+        phase_name = options.get('--id', 'gas')
+        logging.warning("\nFutureWarning: "
+                        "option '--id=...' is superseded by '--phase=...'")
+    else:
+        phase_name = options.get('--phase', 'gas')
 
     if not input_file and not thermo_file:
         print('At least one of the arguments "--input=..." or "--thermo=..."'

interfaces/cython/cantera/composite.py

@@ -38,9 +38,9 @@ class Solution(ThermoPhase, Kinetics, Transport):
         gas = ct.Solution('diamond.yaml', phase='gas')
         diamond = ct.Solution('diamond.yaml', phase='diamond')
 
-    The name of the `Solution` object needs to be unique and defaults to the 
-    *phase* specified in the input file. If another object using the same 
-    constituting information already exists, the name is automatically appended 
+    The name of the `Solution` object needs to be unique and defaults to the
+    *phase* specified in the input file. If another object using the same
+    constituting information already exists, the name is automatically appended
     by a suffix. A custom name can be set via the ``name`` keyword argument of
     the constructor, i.e.::
 
@@ -60,6 +60,12 @@ class Solution(ThermoPhase, Kinetics, Transport):
     ``species`` and ``reactions`` keyword arguments are lists of `Species` and
     `Reaction` objects, respectively.
 
+    Types of underlying models that form the composite `Solution` object are
+    queried using the ``thermo_model``, ``kinetics_model`` and
+    ``transport_model`` attributes; further, the ``composite`` attribute is a
+    shorthand returning a tuple containing the types of the three contitutive
+    models.
+
     For non-trivial uses cases of this functionality, see the examples
     `extract_submechanism.py <https://cantera.org/examples/python/extract_submechanism.py.html>`_
     and `mechanism_reduction.py <https://cantera.org/examples/python/mechanism_reduction.py.html>`_.
@@ -72,7 +78,7 @@ class Solution(ThermoPhase, Kinetics, Transport):
             ideal_gas(name='gas', elements='O H Ar',
                       species='gri30: all',
                       reactions='gri30: all',
-                      options=['skip_undeclared_elements', 'skip_undeclared_species', 
+                      options=['skip_undeclared_elements', 'skip_undeclared_species',
                                'skip_undeclared_third_bodies'],
                       initial_state=state(temperature=300, pressure=101325))'''
         gas = ct.Solution(source=cti_def)