docs/library/enum.rst: Add Enum class.

Signed-off-by: Ihor Nehrutsa <[email protected]>

docs/library/enum.rst

@@ -0,0 +1,168 @@
+:mod:`enum` -- MicroPython Enum class like in the Python
+========================================================
+
+.. module:: enum
+   :synopsis: MicroPython Enum class like in the Python
+
+This module implements enumeration Enum class for the MicroPython.
+
+class Enum -- enumeration
+-------------------------
+
+Class Enum is based in dictionary `dict` class and provides a way to create enumeration
+objects with key-value pairs.
+
+Constructor
+-----------
+
+.. class:: Enum(arg)
+
+   Construct and return a new Enum object using the following parameter:
+
+      - *arg* is the dictionary of key-value pairs.
+
+Usage example::
+
+    from enum import Enum
+    e = Enum({"X": 1, "Y": 2})  # create Enum object from dictionary of key-value pairs
+    print(e)
+    e.A = 'a'                   # add new key-value pair
+    e.B = 'b'
+    print(e)
+    del e.B                     # delete key-value pair
+    print(e)
+    print(e.X)                  # get value from key
+    print(e.key_from_value(2))  # get key from value
+    print(e.B)                  # raise an exception due to no such a key attribute
+
+Output::
+
+    Enum({'X':1, 'Y':2})
+    Enum({'A':'a', 'B':'b', 'X':1, 'Y':2})
+    Enum({'A':'a', 'X':1, 'Y':2})
+    1
+    Y
+    KeyError: No such attribute: B
+
+Methods
+-------
+
+.. _Enum_append:
+.. method:: Enum.append(*arg, **enums):
+
+    Append key-value pairs with the following parameters:
+
+      - *arg* is the dictionary or tuple of dictionaryes or list of dictionaryes: [dict | tuple(dict1, dict2, ...) | list(dict1, dict2, ...)]
+      - *kw_args* are key1=value1, key2=value2, ...
+
+.. method:: Enum.is_value(value)
+
+    Check if value is in the Enum object.
+    Return True if value is in the Enum object, otherwise False.
+
+.. method:: Enum.key_from_value(value)
+
+    Get key from value. If value is not in the Enum object, raise an exception.
+
+Usage example::
+
+    from enum import Enum
+
+    class State(Enum):
+        Stop = 10
+        Run = 20
+        Ready = 30
+
+
+    state = State()
+    print("state:", State())
+
+    current_state = state.Stop
+    print("current_state:", current_state, state.key_from_value(current_state))
+    if current_state == state.Stop:
+        print(" Stop state")
+    if current_state != state.Ready:
+        print(" Not a Ready state")
+        print(" Run!")
+        current_state = state.Run
+    print("current_state:", current_state, state.key_from_value(current_state))
+    # some process
+    i = -1
+    while current_state != state.Ready:
+        i += 1
+        if state.is_value(i):
+            if int(str(State(i))) == state.Ready:
+                current_state = state.Ready
+        print(".", end="")
+    print()
+    print("current_state:", current_state, state.key_from_value(current_state))
+    print("Done!")
+
+Output::
+
+    state: State({'Run':20, 'Stop':10, 'Ready':30})
+    current_state: 10 State.Stop
+     Stop state
+     Not a Ready state
+     Run!
+    current_state: 20 State.Run
+    ...............................
+    current_state: 30 State.Ready
+    Done!
+
+.. warning::
+
+    There is the trouble with the isinstance()/type().
+
+    >>> isinstance(State.Run, State)
+    False
+    >>> State(State.Ready) == State.Ready
+    False
+    >>> int(str(State(State.Ready))) == State.Ready
+    True
+    >>> type(State(State.Ready))
+    <class 'State'>
+    >>> type(state(State.Ready))
+    <class 'int'>
+    >>> state(State.Ready) == State.Ready
+    True
+
+Function
+--------
+
+.. function:: enum(*arg, **kw_args)
+
+    Return Enum object using the following parameters: see :ref:`Enum.append <Enum_append>` method.
+
+Usage examples::
+
+    from enum import Enum
+    e = enum()
+    e
+    e = enum(X=1, Y=2)
+    e
+    e = enum({'X':1, 'Y':2})
+    e
+    e = enum(({'X':1, 'Y':2}, {'A':'a', 'B':'b'}, ))
+    e
+    e = enum([{'X':1, 'Y':2}, {'A':'a', 'B':'b'}, ])
+    e
+
+Output::
+
+    Enum()
+    Enum({'X':1, 'Y':2})
+    Enum({'X':1, 'Y':2})
+    Enum({ 'A':'a', 'B':'b', 'X':1, 'Y':2})
+    Enum({ 'A':'a', 'B':'b', 'X':1, 'Y':2})
+
+.. note::
+
+    ZZZ.
+
+.. seealso::
+
+..
+    :ref:`enum_test.py <enum_test.py>`
+
+    :ref:`enum.py <enum.py>`

docs/library/index.rst

@@ -62,6 +62,7 @@ library.
    builtins.rst
    cmath.rst
    collections.rst
+   enum.rst
    errno.rst
    gc.rst
    gzip.rst