Simplify redefinition of user envelopes or baselines.

Add the `replace` argument to makePDFBaseline and makePDFEnvelope.
Also use more informative name for the factory built classes.

Author: pavoljuhas

diffpy/srreal/pdfbaseline.py

@@ -68,7 +68,7 @@ def _baseline_reduce_with_state(self):
 
 # Python functions wrapper
 
-def makePDFBaseline(name, fnc, **dbattrs):
+def makePDFBaseline(name, fnc, replace=False, **dbattrs):
     '''Helper function for registering Python function as a PDFBaseline.
     This is required for using Python function as PDFCalculator.baseline.
 
@@ -79,6 +79,9 @@ def makePDFBaseline(name, fnc, **dbattrs):
                 float parameters.  The parameters need to be registered as
                 double attributes in the functor class.  The function fnc
                 must be picklable and it must return a float.
+    replace  -- when set replace any PDFBaseline type already registered
+                under the name.  Otherwise raise RuntimeError when the
+                name is taken.
     dbattrs  -- optional float parameters of the wrapped function.
                 These will be registered as double attributes in the
                 functor class.  The wrapped function must be callable as
@@ -102,7 +105,9 @@ def fshiftedline(x, aline, bline):
         # or pdfc.baseline = "shiftedline"
     '''
     from diffpy.srreal.wraputils import _wrapAsRegisteredUnaryFunction
-    return _wrapAsRegisteredUnaryFunction(PDFBaseline, name, fnc, **dbattrs)
+    rv = _wrapAsRegisteredUnaryFunction(PDFBaseline, name, fnc,
+                                        replace=replace, **dbattrs)
+    return rv
 
 # Import delayed tweaks of the extension classes.
 

diffpy/srreal/pdfenvelope.py

@@ -86,7 +86,7 @@ def _envelope_reduce_with_state(self):
 
 # Python functions wrapper
 
-def makePDFEnvelope(name, fnc, **dbattrs):
+def makePDFEnvelope(name, fnc, replace=False, **dbattrs):
     '''Helper function for registering Python function as a PDFEnvelope.
     This is required for using Python function as PDFCalculator envelope.
 
@@ -97,6 +97,9 @@ def makePDFEnvelope(name, fnc, **dbattrs):
                 float parameters.  The parameters need to be registered as
                 double attributes in the functor class.  The function fnc
                 must be picklable and it must return a float.
+    replace  -- when set replace any PDFEnvelope type already registered
+                under the name.  Otherwise raise RuntimeError when the
+                name is taken.
     dbattrs  -- optional float parameters of the wrapped function.
                 These will be registered as double attributes in the
                 functor class.  The wrapped function must be callable as
@@ -121,7 +124,9 @@ def fexpdecay(x, expscale, exptail):
         # or pdfc.addEnvelope("expdecay")
     '''
     from diffpy.srreal.wraputils import _wrapAsRegisteredUnaryFunction
-    return _wrapAsRegisteredUnaryFunction(PDFEnvelope, name, fnc, **dbattrs)
+    rv = _wrapAsRegisteredUnaryFunction(PDFEnvelope, name, fnc,
+                                        replace=replace, **dbattrs)
+    return rv
 
 # Import delayed tweaks of the extension classes.
 

diffpy/srreal/tests/testpdfbaseline.py

@@ -200,6 +200,16 @@ def test_makePDFBaseline(self):
                           parabola_baseline, a=1, b=2, c=3)
         self.assertRaises(RuntimeError, makePDFBaseline, 'parabolabaseline',
                           parabola_baseline, a=1, b=2, c=3)
+        # check replacement of an existing type.
+        makePDFBaseline('linear', parabola_baseline, replace=True,
+                        a=1, b=2, c=4)
+        pbl4 = PDFBaseline.createByType('linear')
+        self.assertEqual(set(('a', 'b', 'c')), pbl4._namesOfDoubleAttributes())
+        self.assertEqual(4, pbl4.c)
+        # check baseline with no attributes
+        pbl5 = makePDFBaseline('myzero', lambda x: 0.0)
+        self.assertEqual(0, pbl5(33))
+        self.assertEqual(set(), pbl5._namesOfDoubleAttributes())
         return
 
 # End of class TestPDFBaseline

diffpy/srreal/wraputils.py

@@ -58,7 +58,7 @@ def setattrFromKeywordArguments(obj, **kwargs):
     return
 
 
-def _wrapAsRegisteredUnaryFunction(cls, regname, fnc, **dbattrs):
+def _wrapAsRegisteredUnaryFunction(cls, regname, fnc, replace=False, **dbattrs):
     '''Helper function for wrapping Python function as PDFBaseline or
     PDFEnvelope functor.  Not intended for direct usage, this function
     is rather called from makePDFBaseline or makePDFEnvelope wrappers.
@@ -71,6 +71,9 @@ def _wrapAsRegisteredUnaryFunction(cls, regname, fnc, **dbattrs):
                 float parameters.  The parameters need to be registered as
                 dbattrs in the functor class.  The function fnc
                 must be picklable and it must return a float.
+    replace  -- when set replace any functor already registered under
+                the regname.  Otherwise raise RuntimeError when regname
+                is taken.
     dbattrs  -- optional float parameters of the wrapped function.
                 These will be registered as double attributes in the
                 functor class.  The wrapped function must be callable as
@@ -118,6 +121,9 @@ def __init__(self):
 
     # End of class RegisteredUnaryFunction
 
+    if replace:
+        RegisteredUnaryFunction._deregisterType(regname)
+    RegisteredUnaryFunction.__name__ = 'User' + cls.__name__ + '_' + regname
     RegisteredUnaryFunction()._registerThisType()
     rv = RegisteredUnaryFunction.createByType(regname)
     assert type(rv) is RegisteredUnaryFunction