wsh Syntax - Version 6

abstract syntax 6

wsh = pipe? ('<>' pipe?)*

kind = '-' | '.' | '=' | '#' | '@'| ':' | '^' | '%'

op = '.' | '-' | '<' | '@' | '!' | '?' | '^' | '%'

primary = op* sConst | op* var | (op* ki)? block

var = name | '{' expr '}'

the first variant is for kindText which allows only text
the second variant is for kindCall or kindFun which are calls: var is the run to call, oPrBlEx give the facultativ arguments
the third variant for the other kinds
$/../ is a blockEnd, neither a primary nor an assignment, $[ is illegal

oPrBlEx = primary | ( op* ('#' | '=' | '<' ) | (op* kind )? spCom+ ) expr

pipe = ('<' oPrBlEx)* (( '>' | '>>') oPrBlEx)? exprStmts ( '|' exprStmts )*

default kind for oPrBlEx is =, default kind for expr given by context, for kind # everything is text

nmBlock = kind? '/' name '/' wsh '/' name '/'

block = kind? '[' wsh ']' | nmBlock

ass = ('='? var)? '=' oPrBlEx

stmt = '$$' oPrBlEx

| 'arg' (var | ',')+

| '@' oPrBlEx

| 'ct' stmt

| 'proc' var? stmt

| ( 'do' | 'with' ) (ass | expr ) stmt

| ('for' | 'forWith' ) var? stmt

exprStmts = ( expr | stmt | 'withNew' )+

	dolNlEscape	ignored	explanation
primary			no $, nl, spaces, comments except, of course within a started block
expr		com	$ only to start a primary, spaces are part of noDo, comments are squashed to 1 or 0 spaces
var		exStr
expP		com sp
pipe	< > >> \| stmt	com sp	com and sp are handled by expr if neighbouring, nl separates stmts and/or expr see stmtExpr and dolStmt
unit	;	com sp	com sp are handled by pipe if neighbouring
nmBlo	ending /.../
block	]
exprBlo		exStr
ass		com sp nl
stmt	stmt	com sp nl

ignored: lexcicals ignored within term, but not before and after (there rule for parent element applies)
exStr: leading and trailing spaces and comments around expr are stripped
dolNlEscape which syntax terms must be prefixed by an escape character, so they are recognized
- mandatory prefixed by '$' if kind is not £
- either prefixed by '$' or nl (sp | com)*, otherwise
stmtExpr = (spCom* | expr) ( nl expr)* (nl spCom*)?
- partial lines besides statements are ingored
dolStmt
- '$$' does neither need nor allow a third $
- both forms of the assignment statement must be prefixed by '$=', but not by '$=='
- all other statements must be prefixed by a single '$'. For historical reason a prefix of '$@' (but not '$@@') is allowed

com = '**' noNL* | '*+' noNL* nl | '$*(' text '$*)'
name = alfaChar (alfaNumChar | '_', '@')*
- wsh variable pool is casesensitive, but not rexx names!
- statement names for, with etc. are not a name, however ${for} is a primary
sp = a single space character
nl = new line (pseudo character in z/os for next line)
noNl = any single character except nl
noDo = any single character neither $ nor nl
text = any text possibly including '$' or nl until to the context dependent stopper, which must be prefixed by '$')
sConst = string constant: single or double quoted String with any nl's: 'abc', "e", 'I''m' etc.