1 # Copyright 2014-2015 ARM Limited 2 # 3 # Licensed under the Apache License, Version 2.0 (the "License"); 4 # you may not use this file except in compliance with the License. 5 # You may obtain a copy of the License at 6 # 7 # http://www.apache.org/licenses/LICENSE-2.0 8 # 9 # Unless required by applicable law or agreed to in writing, software 10 # distributed under the License is distributed on an "AS IS" BASIS, 11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 # See the License for the specific language governing permissions and 13 # limitations under the License. 14 # 15 16 17 """ 18 Routines for doing various type conversions. These usually embody some higher-level 19 semantics than are present in standard Python types (e.g. ``boolean`` will convert the 20 string ``"false"`` to ``False``, where as non-empty strings are usually considered to be 21 ``True``). 22 23 A lot of these are intened to stpecify type conversions declaratively in place like 24 ``Parameter``'s ``kind`` argument. These are basically "hacks" around the fact that Python 25 is not the best language to use for configuration. 26 27 """ 28 import math 29 30 from devlib.utils.misc import isiterable, to_identifier, ranges_to_list, list_to_mask 31 32 33 def identifier(text): 34 """Converts text to a valid Python identifier by replacing all 35 whitespace and punctuation.""" 36 return to_identifier(text) 37 38 39 def boolean(value): 40 """ 41 Returns bool represented by the value. This is different from 42 calling the builtin bool() in that it will interpret string representations. 43 e.g. boolean('0') and boolean('false') will both yield False. 44 45 """ 46 false_strings = ['', '0', 'n', 'no', 'off'] 47 if isinstance(value, basestring): 48 value = value.lower() 49 if value in false_strings or 'false'.startswith(value): 50 return False 51 return bool(value) 52 53 54 def integer(value): 55 """Handles conversions for string respresentations of binary, octal and hex.""" 56 if isinstance(value, basestring): 57 return int(value, 0) 58 else: 59 return int(value) 60 61 62 def numeric(value): 63 """ 64 Returns the value as number (int if possible, or float otherwise), or 65 raises ``ValueError`` if the specified ``value`` does not have a straight 66 forward numeric conversion. 67 68 """ 69 if isinstance(value, int): 70 return value 71 try: 72 fvalue = float(value) 73 except ValueError: 74 raise ValueError('Not numeric: {}'.format(value)) 75 if not math.isnan(fvalue) and not math.isinf(fvalue): 76 ivalue = int(fvalue) 77 if ivalue == fvalue: # yeah, yeah, I know. Whatever. This is best-effort. 78 return ivalue 79 return fvalue 80 81 82 class caseless_string(str): 83 """ 84 Just like built-in Python string except case-insensitive on comparisons. However, the 85 case is preserved otherwise. 86 87 """ 88 89 def __eq__(self, other): 90 if isinstance(other, basestring): 91 other = other.lower() 92 return self.lower() == other 93 94 def __ne__(self, other): 95 return not self.__eq__(other) 96 97 def __cmp__(self, other): 98 if isinstance(basestring, other): 99 other = other.lower() 100 return cmp(self.lower(), other) 101 102 def format(self, *args, **kwargs): 103 return caseless_string(super(caseless_string, self).format(*args, **kwargs)) 104 105 106 def bitmask(value): 107 if isinstance(value, basestring): 108 value = ranges_to_list(value) 109 if isiterable(value): 110 value = list_to_mask(value) 111 if not isinstance(value, int): 112 raise ValueError(value) 113 return value 114
