From b9e1c6f167a5179999a648880d76a5c5e877633c Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Fri, 20 Aug 2021 11:55:04 +0100
Subject: [PATCH] 3540: small improvements to the validator (#3747)

---
 EIPS/eip-3540.md | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/EIPS/eip-3540.md b/EIPS/eip-3540.md
index fab85885..81cf42cf 100644
--- a/EIPS/eip-3540.md
+++ b/EIPS/eip-3540.md
@@ -274,6 +274,8 @@ All cases should be checked for creation transaction, `CREATE` and `CREATE2`.
 
 ## Reference Implementation
 
+### Generic Implementation
+
 ```python
 FORMAT = 0xEF
 MAGIC = 0x00 # To be defined
@@ -288,9 +290,7 @@ def validate_eof(code: bytes):
         return
 
     # Validate format and magic
-    assert(len(code) >= 3)
-    assert(code[1] == MAGIC)
-    assert(code[2] == VERSION)
+    assert(len(code) >= 3 and code[1] == MAGIC and code[2] == VERSION)
 
     # Process section headers
     section_sizes = {S_CODE: 0, S_DATA: 0}
@@ -303,30 +303,31 @@ def validate_eof(code: bytes):
         if section_id == S_TERMINATOR:
             break
 
-        # Unknown section
-        if not section_id in section_sizes:
-            break
+        # Disallow unknown sections
+        assert(section_id in section_sizes)
 
         # Data section preceding code section
-        assert(!(section_id == S_DATA and section_sizes[S_CODE] == 0))
+        assert(not (section_id == S_DATA and section_sizes[S_CODE] == 0))
 
-        # Multiple sections
+        # Multiple sections with the same id
         assert(section_sizes[section_id] == 0)
+
         # Truncated section size
         assert((pos + 1) < len(code))
         section_sizes[section_id] = (code[pos] << 8) | code[pos + 1]
         pos += 2
+
         # Empty section
         assert(section_sizes[section_id] != 0)
 
     # Code section cannot be absent
     assert(section_sizes[S_CODE] != 0)
 
-    # The entire container was scanned
+    # The entire container must be scanned
     assert(len(code) == (pos + section_sizes[S_CODE] + section_sizes[S_DATA]))
 ```
 
-### Simplified implementations
+### Simplified Implementation
 
 Given the rigid rules of EOF1 it is possible to implement support for the container in clients using very simple pattern matching: