"Name Type Description "ab strregular expression for the start of an alternate comment" "ae strregular expression for the end of an alternate comment" "pb strregular expression for start of a procedure" "bb strregular expression for start of a lexical block" "be strregular expression for the end of a lexical block" "cb strregular expression for the start of a comment" "ce strregular expression for the end of a comment" "sb strregular expression for the start of a string" "se strregular expression for the end of a string" "lb strregular expression for the start of a character constant" "le strregular expression for the end of a character constant" "nc strregular expression for a non-comment (see below)" "tl bool present means procedures are only defined at the top lexical level" "oc bool present means upper and lower case are equivalent" "kw stra list of keywords separated by spaces"
Non-comments are required to describe a certain context where a sequence that would normally start a comment loses its special meaning. A typical example for this can be found in Perl, where comments are normally starting with ‘#’, while the string ‘$#’ is an operator on an array.
matches any alphanumeric name. In a procedure definition (pb) the string that matches this symbol is used as the procedure name.
()
grouping
|
alternation
?
last item is optional
\e
preceding any string means that the string will not match an input string if the input string is preceded by an escape character (\). This is typically used for languages (like C) which can include the string delimiter in a string by escaping it.
Unlike other regular expressions in the system, these match words and not characters. Hence something like "(tramp|steamer)flies?" would match "tramp", "steamer", "trampflies", or "steamerflies".
