/**
* Common code for PyFloat, {@link PyInteger} and {@link PyLong} to prepare a {@link
* FloatFormatter} from a parsed specification. The object returned has format method {@link
* FloatFormatter#format(double)}.
*
* @param spec a parsed PEP-3101 format specification.
* @return a formatter ready to use, or null if the type is not a floating point format type.
* @throws PyException(ValueError) if the specification is faulty.
*/
@SuppressWarnings("fallthrough")
static FloatFormatter prepareFormatter(Spec spec) {
// Slight differences between format types
switch (spec.type) {
case 'n':
if (spec.grouping) {
throw Formatter.notAllowed("Grouping", "float", spec.type);
}
// Fall through
case Spec.NONE:
case 'e':
case 'f':
case 'g':
case 'E':
case 'F':
case 'G':
case '%':
// Check for disallowed parts of the specification
if (spec.alternate) {
throw FloatFormatter.alternateFormNotAllowed("float");
}
// spec may be incomplete. The defaults are those commonly used for numeric formats.
spec = spec.withDefaults(Spec.NUMERIC);
return new FloatFormatter(spec);
default:
return null;
}
}
@ExposedMethod(doc = BuiltinDocs.float___format___doc)
final PyObject float___format__(PyObject formatSpec) {
// Parse the specification
Spec spec = InternalFormat.fromText(formatSpec, "__format__");
// Get a formatter for the specification
FloatFormatter f = prepareFormatter(spec);
if (f != null) {
// Bytes mode if formatSpec argument is not unicode.
f.setBytes(!(formatSpec instanceof PyUnicode));
// Convert as per specification.
f.format(value);
// Return a result that has the same type (str or unicode) as the formatSpec argument.
return f.pad().getPyResult();
} else {
// The type code was not recognised in prepareFormatter
throw Formatter.unknownFormat(spec.type, "float");
}
}