RAT4TP.DOC
J Anthony Parker MD, 7-jun-80
Breif ratfor description (see Kernighan W, Plauser PJ: Software Tools
  Addison-Wesley, 1976).
Syntax <name> are metavariable names; {} enclose optional entries:
	<program> = <statement> | <program><; or newline><statement>
	<statement> =  FOR({<statement>};{<boolean>};{<statement>})<statement>
		     | WHILE(<boolean>) <statement>
		     | REPEAT <statement>
			{UNTIL(<boolean>)}
		     | IF(<boolean>) <statement>
			{ELSE <statement>}
		     | DO <limits>
			<statement>
		     | SWITCH (expression) [<case list>]
		     | [<program>]
		     | NEXT
		     | BREAK
		     | STRING <name> '<string>'
		     | <label statement>
		     | <label name> <statement>
		     | <almost any fortran statement>
		     | DEFINE <name> <string>
		     | UNDEFINE <name>
		     | INCLUDE <file specification>
	<limits> = Fortran limits e.g. I=1,10
	<case list> =  CASE <integer value> : <program>
		     | CASE DEFAULT : <program>
		     | CASE '<character>' : <program>
		     | <case list>
			CASE <integer or '<character>' or DEFAULT> : <program>
	<label statement> =  LABEL <label name>
			   | <label statement>, <label name>
Some semantics:
	FOR(initialization ; test ; reinitialization)
		The test is performed at the top of the loop.
	DO
		Fortran DO statement.
	STRING <name> '<string>'
		CHARACTER must be defined as BYTE.(i.e. DEFINE CHARACTER BYTE)
		SLEN is a preprocess time function which returns the length of
		the string. Within the string: \b=BS, \e=ESC, \f=FF, \l=LF,
		\n=CR-LF, \r=CR, \t=TAB, \\=\, \^*=<cntrl*>, \ddd=ddd<octal>.
	SWITCH
		Translates into a computed GOTO; therefore, a small integer
		range should be used.  Control falls throught the cases;
		therefore, each case is typically terminated with BREAK.
		\ string construction is supported.
	LABEL <label name>
		Label name can be used as a fortran statement label e.g. for
		format statements, or for ERR= and END= options.
		UNDEFINE will undefine label name.
Special features:
	longnames (including '_' and '&' in the versions running on PDP11's)
		are uniquely converted to fortran names.
	'%' as the first character in a line will pass a whole line
		through to the output unaltered.  In other positions
		it passes the next character.
	'@'<number> translates octal constant <number> to decimal constant.
	'#' starts a comment which is terminated with a newline.
	'/*' starts a comment which is terminated with '*/'.
	"'" or '"' can be used to delimit strings.
	'[', ']' or '{', '}' can be used to delimit statements.
	'\'<cr> continues a statement on the next line.  '\' is discarded.
	',', '*', '+', '-', '(', '&', and '|' at the end of a line
		cause the statement to be continued on the next line.
	'&' translates to .AND.
	'|' and '\' translate to .OR.
	'<' translates to .LT.
	'>' translates to .GT.
	'^' and '!' translate to .NOT.
	'<=' translates to .LE.
	'==' translates to .EQ.
	'>=' translates to .GE.
	'^=', '!=' and '<>' translate to .NE.