def error_leader(self, infile=None, lineno=None):
if infile is None:<EOL><INDENT>infile = self.infile<EOL><DEDENT>if lineno is None:<EOL><INDENT>lineno = self.lineno<EOL><DEDENT>return "<STR_LIT>" % (infile, lineno)<EOL>
Emit a C-compiler-like, Emacs-friendly error-message leader.