Add bits, precision, resolution constants

Author: juntyr

quaddtype/numpy_quaddtype/__init__.py

@@ -13,11 +13,13 @@
     'SleefQuadPrecDType', 'LongDoubleQuadPrecDType', 'is_longdouble_128', 
     # Constants
     'pi', 'e', 'log2e', 'log10e', 'ln2', 'ln10', 'max_value', 'epsilon',
-    'smallest_normal', 'smallest_subnormal',
+    'smallest_normal', 'smallest_subnormal', 'bits', 'precision', 'resolution',
     # QuadBLAS related functions
     'set_num_threads', 'get_num_threads', 'get_quadblas_version'
 ]
 
+import numpy as np
+
 def SleefQuadPrecision(value):
     return QuadPrecision(value, backend='sleef')
 
@@ -40,3 +42,6 @@ def LongDoubleQuadPrecDType():
 epsilon = get_sleef_constant("epsilon")
 smallest_normal = get_sleef_constant("smallest_normal")
 smallest_subnormal = get_sleef_constant("smallest_subnormal")
+bits = SleefQuadPrecDType().itemsize * 8
+precision = int(-np.log10(epsilon))
+resolution = SleefQuadPrecision(10) ** (-precision)

quaddtype/tests/test_quaddtype.py

@@ -19,11 +19,16 @@ def test_math_constant(name, expected):
     assert np.float64(getattr(numpy_quaddtype, name)) == expected
 
 
-@pytest.mark.parametrize("name", ["max_value", "epsilon", "smallest_normal", "smallest_subnormal"])
+@pytest.mark.parametrize("name", ["max_value", "epsilon", "smallest_normal", "smallest_subnormal", "resolution"])
 def test_finfo_constant(name):
     assert isinstance(getattr(numpy_quaddtype, name), QuadPrecision)
 
 
+@pytest.mark.parametrize("name,value", [("bits", 128), ("precision", 33)])
+def test_finfo_int_constant(name, value):
+    assert getattr(numpy_quaddtype, name) == value
+
+
 def test_basic_equality():
     assert QuadPrecision("12") == QuadPrecision(
         "12.0") == QuadPrecision("12.00")