Large int bug (#238)

There was an issue where in some environments (but not all) large numbers such as 8.034023767017109e+27 whch were ints would be printed as an the int 8034023767017108950029959168 and then the C++ compiler would complain as that's more than the maximum int value. This has been fixed by only printing ints as ints if they are MIN_INT < number < MAX_INT else we print them as a float (and we get the sceintific notation).

RELEASE.md

@@ -1,5 +1,9 @@
 # Release 0.9.6
+- This release fixes a bug printing large integers, in some environments: Large numbers such as 8.034023767017109e+27 whch were actually ints would be printed as an the int 8034023767017108950029959168 and then the C++ compiler would complain as that's more than the maximum int value. This has been fixed by only printing ints as ints if they are `MIN_INT < number < MAX_INT` else we print them as a float (and we get the sceintific notation).
+
+# Release 0.9.6 (yanked)
 - Fixed tests to pass with sympy 1.10 and required latest cellmlmanip, which also workes with sympy1.10. Updated sympy requirement to be >=1.9, < 1.11
+- This release was yanked due to a bug printing large integers
 
 # Release 0.9.5
 - Corrected a type in the generated output for `--rush-larsen-c`

chaste_codegen/_chaste_printer.py

@@ -12,6 +12,10 @@
 from sympy.printing.precedence import precedence
 
 
+C_MAX_INT = 2147483647
+C_MIN_INT = -2147483647
+
+
 class ChastePrinter(Printer):
     """
     Converts Sympy expressions to strings for use in Chaste code generation.
@@ -141,18 +145,19 @@ def _print_ternary(self, cond, expr):
         return parts
 
     def _print_IntegerConstant(self, expr):
-        return cxxcode(int(expr), standard='C++11')
+        return self._print_int(float(expr))
 
     def _print_float(self, expr):
         """ Handles ``float``s. """
-        if expr.is_integer():
+        # print integers as int if they are between min & max int in c++
+        if expr.is_integer() and C_MIN_INT < expr < C_MAX_INT:
             return cxxcode(int(expr), standard='C++11')
         else:
-            return cxxcode(expr, standard='C++11')
+            return cxxcode(float(expr), standard='C++11')
 
     def _print_int(self, expr):
         """ Handles ``ints``s. """
-        return cxxcode(int(expr), standard='C++11')
+        return self._print_float(float(expr))
 
     def _print_ITE(self, expr):
         """ Handles ITE (if then else) objects by rewriting them as Piecewise """