fix lint, add notes

vyper/codegen/expr.py

@@ -51,13 +51,7 @@
 )
 from vyper.semantics.types.bytestrings import _BytestringT
 from vyper.semantics.types.shortcuts import BYTES32_T, UINT256_T
-from vyper.utils import (
-    DECIMAL_DIVISOR,
-    bytes_to_int,
-    is_checksum_encoded,
-    string_to_bytes,
-    vyper_warn,
-)
+from vyper.utils import DECIMAL_DIVISOR, is_checksum_encoded, string_to_bytes, vyper_warn
 
 ENVIRONMENT_VARIABLES = {"block", "msg", "tx", "chain"}
 
@@ -142,15 +136,16 @@ def _make_bytelike(self, btype, bytez, bytez_length):
         assert isinstance(bytez, bytes)
         label = _freshname("bytesdata")
         len_ = len(bytez)
+        # NOTE: addl opportunities for optimization:
+        # - intern repeated bytestrings
+        # - instantiate into memory lazily, pass around bytestring
+        #   literals in IR.
         ret.append(["data", label, bytez])
         ret.append(["codecopy", placeholder + 32, ["symbol", label], len_])
         ret.append(["mstore", placeholder, len_])
         ret.append(placeholder)
         return IRnode.from_list(
-            ret,
-            typ=btype,
-            location=MEMORY,
-            annotation=f"Create {btype}: {bytez}",
+            ret, typ=btype, location=MEMORY, annotation=f"Create {btype}: {repr(bytez)}"
         )
 
     # True, False, None constants

vyper/utils.py

@@ -159,6 +159,7 @@ def hex_to_int(inp):
 
 
 # Converts bytes to an integer
+# TODO: use int.from_bytes
 def bytes_to_int(bytez):
     o = 0
     for b in bytez: