feat(rpc): make python client compat with python 3.7

cryptol-remote-api/python/cryptol/bitvector.py

@@ -99,7 +99,7 @@ def widen(self, n : int) -> 'BV':
         Args:
             n (int): How many bits wider the returned ``BV`` should be than ``self`` (must be nonnegative).
         """
-        if not isinstance(n, int) or n < 0:
+        if not isinstance(n, int) or n < 0: # type: ignore
             raise ValueError(f'``widen`` expects a nonnegative integer, but got {n!r}')
         else:
             return BV(self.__size + n, self.__value)
@@ -124,7 +124,7 @@ def concat(self, *others : 'BV') -> 'BV':
                 ``others`` in order on the right.
         """
         return reduce(lambda acc, b: acc.__concat_single(b), others, self)
-    
+
     @staticmethod
     def join(*bs : 'BV') -> 'BV':
         """Concatenate the given ``BV``s in order.
@@ -178,6 +178,10 @@ def __index__(self) -> int:
         """Equivalent to ``self.value()``."""
         return self.__value
 
+    def __int__(self) -> int:
+        """Equivalent to ``self.value()``."""
+        return self.__value
+
     def __len__(self) -> int:
         """Equivalent to ``self.size()``."""
         return self.__size
@@ -190,10 +194,10 @@ def __bytes__(self) -> bytes:
 
     def split(self, size : int) -> List['BV']:
         """Split ``self`` into a list of ``BV``s of length ``size``.
-        
+
         :param size: Size of segments to partition ``self`` into (must evently divide ``self.size()``).
         """
-        if not isinstance(size, int) or size <= 0:
+        if not isinstance(size, int) or size <= 0: # type: ignore
             raise ValueError(f'`size` argument to splits must be a positive integer, got {size!r}')
         if not self.size() % size == 0:
             raise ValueError(f'{self!r} is not divisible into equal parts of size {size!r}')
@@ -209,7 +213,7 @@ def popcount(self) -> int:
     @staticmethod
     def from_bytes(bs : bytes, *, size : Optional[int] =None, byteorder : str ='big') -> 'BV':
         """Convert the given bytes ``bs`` into a ``BV``.
-        
+
         :param bs: Bytes to convert to a ``BV``.
         :param size, optional: Desired ``BV``'s size (must be large enough to represent ``bs``). The
             default (i.e., ``None``) will result in a ``BV`` of size ``len(bs) * 8``.
@@ -246,7 +250,7 @@ def with_bit(self, index : int, set_bit : bool) -> 'BV':
     def with_bits(self, low : int, bits : 'BV') -> 'BV':
         """Return a ``BV`` identical to ``self`` but with the bits from ``low`` to
         ``low + bits.size() - 1`` replaced by the bits from ``bits``."""
-        if not isinstance(low, int) or low < 0 or low >= self.__size:
+        if not isinstance(low, int) or low < 0 or low >= self.__size: # type: ignore
             raise ValueError(f'{low!r} is not a valid low bit index for {self!r}')
         elif not isinstance(bits, BV):
             raise ValueError(f'Expected a BV but got {bits!r}')

cryptol-remote-api/python/cryptol/connection.py

@@ -51,24 +51,39 @@ def connect(command : Optional[str]=None,
         if url is not None:
             raise ValueError("A Cryptol server URL cannot be specified with a command currently.")
         c = CryptolConnection(command, cryptol_path)
-    elif url is not None:
+    # User-passed url?
+    if c is None and url is not None:
         c = CryptolConnection(ServerConnection(HttpProcess(url)), cryptol_path)
-    elif (command := os.getenv('CRYPTOL_SERVER')) is not None and (command := find_executable(command)) is not None:
-        c = CryptolConnection(command+" socket", cryptol_path=cryptol_path)
-    elif (url := os.getenv('CRYPTOL_SERVER_URL')) is not None:
-        c = CryptolConnection(ServerConnection(HttpProcess(url)), cryptol_path)
-    elif (command := find_executable('cryptol-remote-api')) is not None:
-        c = CryptolConnection(command+" socket", cryptol_path=cryptol_path)
+    # Check `CRYPTOL_SERVER` env var if no connection identified yet
+    if c is None:
+        command = os.getenv('CRYPTOL_SERVER')
+        if command is not None:
+            command = find_executable(command)
+            if command is not None:
+                c = CryptolConnection(command+" socket", cryptol_path=cryptol_path)
+    # Check `CRYPTOL_SERVER_URL` env var if no connection identified yet
+    if c is None:
+        url = os.getenv('CRYPTOL_SERVER_URL')
+        if url is not None:
+            c = CryptolConnection(ServerConnection(HttpProcess(url)), cryptol_path)
+    # Check if `cryptol-remote-api` is in the PATH if no connection identified yet
+    if c is None:
+        command = find_executable('cryptol-remote-api')
+        if command is not None:
+            c = CryptolConnection(command+" socket", cryptol_path=cryptol_path)
+    # Raise an error if still no connection identified yet
+    if c is not None:
+        if reset_server:
+            CryptolResetServer(c)
+        return c
     else:
         raise ValueError(
             """cryptol.connect requires one of the following:",
                1) a command to launch a cryptol server is the first positional argument,
                2) a URL to connect to a running cryptol server is provided via the `url` keyword argument,
                3) the environment variable `CRYPTOL_SERVER` must refer to a valid server executable, or
                4) the environment variable `CRYPTOL_SERVER_URL` must refer to the URL of a running cryptol server.""")
-    if reset_server:
-        CryptolResetServer(c)
-    return c
+
 
 
 def connect_stdio(command : str, cryptol_path : Optional[str] = None) -> CryptolConnection:
@@ -102,7 +117,7 @@ class CryptolConnection:
     proc: ServerProcess
 
     def __init__(self,
-                command_or_connection : Union[str, ServerConnection, ServerProcess], 
+                command_or_connection : Union[str, ServerConnection, ServerProcess],
                 cryptol_path : Optional[str] = None) -> None:
         self.most_recent_result = None
         if isinstance(command_or_connection, ServerProcess):

cryptol-remote-api/python/pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "cryptol"
-version = "2.11.0"
+version = "2.11.1"
 readme = "README.md"
 keywords = ["cryptography", "verification"]
 description = "Cryptol client for the Cryptol 2.11 RPC server"
@@ -12,7 +12,7 @@ include = [
 ]
 
 [tool.poetry.dependencies]
-python = "^3.8"
+python = ">=3.7.0"
 requests = "^2.25.1"
 BitVector = "^3.4.9"
 argo-client = "0.0.4"