// advanceParam attempts to advance to the start of the next
// parameter and returns true if the advance succeeded, otherwise
// false if the lexer is at EOF or if unexpected characters were
// found.
func advanceParam(l *lexrec.Lexer) bool {
if l.Peek() == lexrec.EOF {
return false
}
l.AcceptRun(whitespace)
if l.Next() != ',' {
l.Errorf("advanceParam: expected comma, got %q", l.Peek())
return false
}
l.AcceptRun(whitespace)
l.Skip()
return true
}