Improvements

Author: ShikharJ

symengine/printing.py

@@ -1,8 +1,12 @@
-from symengine.lib.symengine_wrapper import ccode, _sympify
+from symengine.lib.symengine_wrapper import ccode, _sympify, Basic
 
 class CCodePrinter:
 
     def doprint(self, expr, assign_to=None):
+        if not isinstance(assign_to, (Basic, type(None), str)):
+            raise TypeError("{0} cannot assign to object of type {1}".format(
+                    type(self).__name__, type(assign_to)))
+
         expr = _sympify(expr)
         if not assign_to:
             if expr.is_Matrix:

symengine/tests/CMakeLists.txt

@@ -8,6 +8,7 @@ install(FILES __init__.py
     test_number.py
     test_matrices.py
     test_ntheory.py
+    test_printing.py
     test_sage.py
     test_series_expansion.py
     test_subs.py

symengine/tests/test_printing.py

@@ -0,0 +1,27 @@
+from symengine.utilities import raises
+from symengine.lib.symengine_wrapper import (ccode, Symbol, sqrt, Pow, Max, sin, Integer, MutableDenseMatrix)
+from symengine.printing import CCodePrinter
+
+def test_ccode():
+    x = Symbol("x")
+    y = Symbol("y")
+    assert ccode(x) == "x"
+    assert ccode(x**3) == "pow(x, 3)"
+    assert ccode(x**(y**3)) == "pow(x, pow(y, 3))"
+    assert ccode(x**-1.0) == "pow(x, -1.0)"
+    assert ccode(Max(x, x*x)) == "max(x, pow(x, 2))"
+    assert ccode(sin(x)) == "sin(x)"
+    assert ccode(Integer(67)) == "67"
+    assert ccode(Integer(-1)) == "-1"
+
+def test_CCodePrinter():
+    x = Symbol("x")
+    y = Symbol("y")
+    myprinter = CCodePrinter()
+
+    assert myprinter.doprint(1+x, "bork") == "bork = 1 + x;"
+    assert myprinter.doprint(1*x) == "x"
+    assert myprinter.doprint(MutableDenseMatrix(1, 2, [x, y]), "larry") == "larry[0] = x;\nlarry[1] = y;"
+    raises(TypeError, lambda: myprinter.doprint(sin(x), Integer))
+    raises(RuntimeError, lambda: myprinter.doprint(MutableDenseMatrix(1, 2, [x, y])))
+