Closes #32

README.md

@@ -788,8 +788,12 @@ Parsed fields:
 
 ### Signal validation and parse errors
 
-`SG_` statements are matched completely. Signal names must be nonempty and
-contain no whitespace. Spaces and tabs are accepted between syntax elements;
+`SG_` statements are read completely with an iterative scanner. Signal parsing
+and numeric conversion do not use recursive regular-expression matching, so long
+fields do not consume stack space proportional to their length. No new statement
+length limit is imposed; valid long fields are preserved, and malformed statements
+return the usual source diagnostics. Signal names must be nonempty and contain no
+whitespace. Spaces and tabs are accepted between syntax elements;
 byte order and signedness remain adjacent (`@0+`, `@0-`, `@1+`, or `@1-`).
 A quoted unit (which may be empty) and a nonempty comma-separated receiver
 list are required. Unexpected trailing fields are rejected.