Rename function prepend to append

and swap the arguments, for consistency with `Mapping.then`

include/astshim/functional.h

@@ -48,17 +48,15 @@ namespace ast {
  * original FrameSets (in particular, reassignments of their base or current
  * frames) shall not affect it.
  *
- * @param second, first the FrameSets to concatenate. The operations are given
- *                      in right-to-left order for consistency with, e.g.,
- *                      Mapping::of.
+ * @param first, second the FrameSets to concatenate.
  * @return a pointer to a combined FrameSet as described above
  *
  * Example: if `first` has 3 frames and `second `has 4, then the result shall
  *          contain 7 frames, of which frames 1-3 are the same as frames 1-3 of
- *          `first`, in order, and merged frames `4-7` are the same as frames
+ *          `first`, in order, and frames 4-7 are the same as frames
  *          1-4 of `second`, in order.
  */
-std::shared_ptr<FrameSet> prepend(FrameSet const& second, FrameSet const& first);
+std::shared_ptr<FrameSet> append(FrameSet const& first, FrameSet const& second);
 
 }  // namespace ast
 

python/astshim/functional.cc

@@ -34,7 +34,7 @@ PYBIND11_PLUGIN(functional) {
 
     py::module::import("astshim.frameSet");
 
-    mod.def("prepend", &prepend, "second"_a, "first"_a);
+    mod.def("append", &append, "first"_a, "second"_a);
 
     return mod.ptr();
 }

src/functional.cc

@@ -25,7 +25,7 @@
 
 namespace ast {
 
-std::shared_ptr<FrameSet> prepend(FrameSet const& second, FrameSet const& first) {
+std::shared_ptr<FrameSet> append(FrameSet const& first, FrameSet const& second) {
     std::shared_ptr<FrameSet> const merged = first.copy();
     std::shared_ptr<FrameSet> const newFrames = second.copy();
 

tests/test_prepend.py → tests/test_append.py

@@ -2,11 +2,11 @@
 import unittest
 from numpy.testing import assert_allclose
 
-from astshim import Frame, SkyFrame, UnitMap, FrameSet, prepend
+from astshim import Frame, SkyFrame, UnitMap, FrameSet, append
 from astshim.test import makeForwardPolyMap, makeTwoWayPolyMap
 
 
-class TestFrameSetPrepend(unittest.TestCase):
+class TestFrameSetAppend(unittest.TestCase):
 
     def makeFrameSet(self, nIn, nOut):
         """Create a FrameSet with the specified dimensions.
@@ -41,16 +41,16 @@ def makeFrameSet(self, nIn, nOut):
         assert frameSet.getFrame(4).ident == "fork"
         return frameSet
 
-    def test_PrependEffect(self):
+    def test_AppendEffect(self):
         """Check that a concatenated FrameSet transforms correctly.
         """
         set1 = self.makeFrameSet(2, 3)
         set2 = self.makeFrameSet(3, 1)
-        set12 = prepend(set2, set1)
+        set12 = append(set1, set2)
 
         # Can't match 1D output to 2D input
         with self.assertRaises(RuntimeError):
-            prepend(set1, set2)
+            append(set2, set1)
 
         x = [1.2, 3.4]
         y_merged = set12.tranForward(x)
@@ -68,15 +68,15 @@ def test_PrependEffect(self):
         self.assertEqual(set2.base, 1)
         self.assertEqual(set2.current, 3)
 
-    def test_PrependFrames(self):
+    def test_AppendFrames(self):
         """Check that a concatenated FrameSet preserves all Frames.
         """
         set1 = self.makeFrameSet(1, 3)
         # AST docs say FrameSets always have contiguously numbered frames,
         # but let's make sure
         set1.removeFrame(2)
         set2 = self.makeFrameSet(3, 2)
-        set12 = prepend(set2, set1)
+        set12 = append(set1, set2)
 
         self.assertEquals(set1.nFrame + set2.nFrame,
                           set12.nFrame)
@@ -100,13 +100,13 @@ def test_PrependFrames(self):
             else:
                 self.assertFalse(offset + i == set12.current)
 
-    def test_PrependIndependent(self):
+    def test_AppendIndependent(self):
         """Check that a concatenated FrameSet is not affected by changes
         to its constituents.
         """
         set1 = self.makeFrameSet(3, 3)
         set2 = self.makeFrameSet(3, 3)
-        set12 = prepend(set2, set1)
+        set12 = append(set1, set2)
 
         nTotal = set12.nFrame
         x = [1.2, 3.4, 5.6]
@@ -122,14 +122,14 @@ def test_PrependIndependent(self):
         self.assertEquals(set12.nFrame, nTotal)
         self.assertEquals(set12.tranForward(x), y)
 
-    def test_PrependMismatch(self):
-        """Check that prepend behaves as expected when joining non-identical frames.
+    def test_AppendMismatch(self):
+        """Check that append behaves as expected when joining non-identical frames.
         """
         set1 = self.makeFrameSet(3, 2)
         set2 = self.makeFrameSet(2, 3)
         set1.addFrame(FrameSet.CURRENT, makeForwardPolyMap(2, 2),
                       SkyFrame("Ident=sky"))
-        set12 = prepend(set2, set1)
+        set12 = append(set1, set2)
 
         x = [1.2, 3.4, 5.6]
         y_merged = set12.tranForward(x)