wsh3 Syntax

wsh2 → wsh3

wsh2	wsh3	comment
$>.fEdit()	$>. fEdit()	nach . kommt in wsh3 primary, damit es expression gibt, braucht es Space

wsh	ws2	comment
$-{...}	$-[...$]	geschweifte Klammern nur noch für Variabeln
$.$abc	$.abc	primary brauchen und erlauben keine $ mehr
$@abc()	$@abc	call syntax ohne Klammern
$@abc{arg}	$@%[abc arg$]	call syntax mit Argumenten
$@.<$dsn ::F	$@<-=[$dsn ::F$]	nach file Operator kommt primary, nicht expression (aber pipe redirect immer noch expr!)

todo

Implementation Problems

pipe: syntax für input String, und Mischung String files (wsh und pipe!)
$@ exprBlock hat nachteile: $@abc funktioniert nicht mehr direkt, $@.$.abc o.ä. (siehe tst) ist kontraintuitiv - besser primary?
directives: alte Syntax mit benannten units wirklich überflüssig - mit $@proc erreich man selbes ... --- syntax geändert sodass zwischen $#@ und nl verarbeitet wird

idee: var = name | '{' exprS '}' und { } brauchen wir nur noch für das, block wird nur [] oder //

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

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

primary = sConst | var | block

var = name | '{' expr '}'

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

pipe = ('<' oPrBlEx)* (( '>' | '>>') oPrBlEx)? ( stmt | expr )+ ( '|' ( stmt | expr )+ )*

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

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

nmBlock = kind? '/' name '/' unit '/' name '/'

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

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

default kind for oPrBlEx is =, at least one '=', without var only if a named block, see assCon

stmt = '$$' oPrBlEx

| '@' oPrBlEx

| 'ct' stmt

| 'proc' var? stmt

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

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

| 'table' (var | '.' expr)? nl? ('<'? var '>'? )+

wsh = nl'$#version'version)? (nl unit)? ( nl'$#' ( kind (spCom* nl)? unit | hook nl unit | ('*' | 'out' | 'end') textLi+ ) )*

hook = name noNl*

The details of the syntax is different depending on the context (which '=' is mandatory, optional, forbidden)

	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 | '$*(' clText '$*)'
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 singel character except nl
noDo = any single character neither $ nor nl
textLi = any text possibly including '$' until nl (end of line) , or the context dependent stopper, which must be prefixed by '$' and start at the beginning of the line)
sConst = string constant: single or double quoted String with any nl's: 'abc', "e", 'I''m' etc.