//
// EBNF to be viewd at https://www.bottlecaps.de/rr/ui
//
// From Domingo Alvarez Duarte (20 September 2023)
//
// Copy and paste this at https://www.bottlecaps.de/rr/ui
// in the 'Edit Grammar' tab
// then click the 'View Diagram' tab.
//

program::=
	  decls

decls::=
	  /*%empty*/
	| decls decl

decl::=
	  record
	| proc
	| global
	| link
	| invocable

invocable::=
	  INVOCABLE invoclist

invoclist::=
	  invocop
	| invoclist COMMA invocop

invocop::=
	  IDENT
	| STRINGLIT
	| STRINGLIT COLON INTLIT

link::=
	  LINK lnklist

lnklist::=
	  lnkfile
	| lnklist COMMA lnkfile

lnkfile::=
	  IDENT
	| STRINGLIT

global::=
	  GLOBAL idlist

record::=
	  RECORD IDENT LPAREN fldlist RPAREN

fldlist::=
	  /*%empty*/
	| idlist

proc::=
	  prochead SEMICOL locals initial procbody END

prochead::=
	  PROCEDURE IDENT LPAREN arglist RPAREN

arglist::=
	  /*%empty*/
	| idlist
	| idlist LBRACK RBRACK

idlist::=
	  IDENT
	| idlist COMMA IDENT

locals::=
	  /*%empty*/
	| locals retention idlist SEMICOL

retention::=
	  LOCAL
	| STATIC

initial::=
	  /*%empty*/
	| INITIAL expr SEMICOL

procbody::=
	  /*%empty*/
	| nexpr SEMICOL procbody

nexpr::=
	  /*%empty*/
	| expr

expr::=
	  expr1a
	| expr AND expr1a

expr1a::=
	  expr1
	| expr1a QMARK expr1

expr1::=
	  expr2
	| expr2 SWAP expr1
	| expr2 ASSIGN expr1
	| expr2 REVSWAP expr1
	| expr2 REVASSIGN expr1
	| expr2 AUGCONCAT expr1
	| expr2 AUGLCONCAT expr1
	| expr2 AUGDIFF expr1
	| expr2 AUGUNION expr1
	| expr2 AUGPLUS expr1
	| expr2 AUGMINUS expr1
	| expr2 AUGSTAR expr1
	| expr2 AUGINTER expr1
	| expr2 AUGSLASH expr1
	| expr2 AUGMOD expr1
	| expr2 AUGCARET expr1
	| expr2 AUGNMEQ expr1
	| expr2 AUGEQUIV expr1
	| expr2 AUGNMGE expr1
	| expr2 AUGNMGT expr1
	| expr2 AUGNMLE expr1
	| expr2 AUGNMLT expr1
	| expr2 AUGNMNE expr1
	| expr2 AUGNEQUIV expr1
	| expr2 AUGSEQ expr1
	| expr2 AUGSGE expr1
	| expr2 AUGSGT expr1
	| expr2 AUGSLE expr1
	| expr2 AUGSLT expr1
	| expr2 AUGSNE expr1
	| expr2 AUGQMARK expr1
	| expr2 AUGAND expr1
	| expr2 AUGAT expr1

expr2::=
	  expr3
	| expr2 TO expr3
	| expr2 TO expr3 BY expr3

expr3::=
	  expr4
	| expr4 BAR expr3

expr4::=
	  expr5
	| expr4 SEQ expr5
	| expr4 SGE expr5
	| expr4 SGT expr5
	| expr4 SLE expr5
	| expr4 SLT expr5
	| expr4 SNE expr5
	| expr4 NMEQ expr5
	| expr4 NMGE expr5
	| expr4 NMGT expr5
	| expr4 NMLE expr5
	| expr4 NMLT expr5
	| expr4 NMNE expr5
	| expr4 EQUIV expr5
	| expr4 NEQUIV expr5

expr5::=
	  expr6
	| expr5 CONCAT expr6
	| expr5 LCONCAT expr6

expr6::=
	  expr7
	| expr6 PLUS expr7
	| expr6 DIFF expr7
	| expr6 UNION expr7
	| expr6 MINUS expr7

expr7::=
	  expr8
	| expr7 STAR expr8
	| expr7 INTER expr8
	| expr7 SLASH expr8
	| expr7 MOD expr8

expr8::=
	  expr9
	| expr9 CARET expr8

expr9::=
	  expr10
	| expr9 BACKSLASH expr10
	| expr9 AT expr10
	| expr9 BANG expr10

expr10::=
	  expr11
	| AT expr10
	| NOT expr10
	| BAR expr10
	| CONCAT expr10
	| LCONCAT expr10
	| DOT expr10
	| BANG expr10
	| DIFF expr10
	| PLUS expr10
	| STAR expr10
	| SLASH expr10
	| CARET expr10
	| INTER expr10
	| TILDE expr10
	| MINUS expr10
	| NMEQ expr10
	| NMNE expr10
	| SEQ expr10
	| SNE expr10
	| EQUIV expr10
	| UNION expr10
	| QMARK expr10
	| NEQUIV expr10
	| BACKSLASH expr10

expr11::=
	  literal
	| section
	| return
	| if
	| case
	| while
	| until
	| every
	| repeat
	| CREATE expr
	| IDENT
	| NEXT
	| BREAK nexpr
	| LPAREN exprlist RPAREN
	| LBRACE compound RBRACE
	| LBRACK exprlist RBRACK
	| expr11 LBRACK exprlist RBRACK
	| expr11 LBRACE RBRACE
	| expr11 LBRACE pdcolist RBRACE
	| expr11 LPAREN exprlist RPAREN
	| expr11 DOT IDENT
	| AND FAIL
	| AND IDENT

while::=
	  WHILE expr
	| WHILE expr DO expr

until::=
	  UNTIL expr
	| UNTIL expr DO expr

every::=
	  EVERY expr
	| EVERY expr DO expr

repeat::=
	  REPEAT expr

return::=
	  FAIL
	| RETURN nexpr
	| SUSPEND nexpr
	| SUSPEND expr DO expr

if::=
	  IF expr THEN expr
	| IF expr THEN expr ELSE expr

case::=
	  CASE expr OF LBRACE caselist RBRACE

caselist::=
	  cclause
	| caselist SEMICOL cclause

cclause::=
	  DEFAULT COLON expr
	| expr COLON expr

exprlist::=
	  nexpr
	| exprlist COMMA nexpr

pdcolist::=
	  nexpr
	| pdcolist COMMA nexpr

literal::=
	  INTLIT
	| REALLIT
	| STRINGLIT
	| CSETLIT

section::=
	  expr11 LBRACK expr sectop expr RBRACK

sectop::=
	  COLON
	| PCOLON
	| MCOLON

compound::=
	  nexpr
	| nexpr SEMICOL compound

//Tokens

/* reserved words */

BREAK ::= "break"
BY ::= "by"
CASE ::= "case"
CREATE ::= "create"
DEFAULT ::= "default"
DO ::= "do"
ELSE ::= "else"
END ::= "end"
EVERY ::= "every"
FAIL ::= "fail"
GLOBAL ::= "global"
IF ::= "if"
INITIAL ::= "initial"
INVOCABLE ::= "invocable"
LINK ::= "link"
LOCAL ::= "local"
NEXT ::= "next"
NOT ::= "not"
OF ::= "of"
PROCEDURE ::= "procedure"
RECORD ::= "record"
REPEAT ::= "repeat"
RETURN ::= "return"
STATIC ::= "static"
SUSPEND ::= "suspend"
THEN ::= "then"
TO ::= "to"
UNTIL ::= "until"
WHILE ::= "while"

operators ::= /* */

BANG ::= "!"
MOD ::= "%"
AUGMOD ::= "%:="
AND ::= "&"
AUGAND ::= "&:="
STAR ::= "*"
AUGSTAR ::= "*:="
INTER ::= "**"
AUGINTER ::= "**:="
PLUS ::= "+"
AUGPLUS ::= "+:="
UNION ::= "++"
AUGUNION ::= "++:="
MINUS ::= "-"
AUGMINUS ::= "-:="
DIFF ::= "--"
AUGDIFF ::= "--:="
DOT ::= "."
SLASH ::= "/"
AUGSLASH ::= "/:="
ASSIGN ::= ":="
SWAP ::= ":=:"
NMLT ::= "<"
AUGNMLT ::= "<:="
REVASSIGN ::= "<-"
REVSWAP ::= "<->"
SLT ::= "<<"
AUGSLT ::= "<<:="
SLE ::= "<<="
AUGSLE ::= "<<=:="
NMLE ::= "<="
AUGNMLE ::= "<=:="
NMEQ ::= "="
AUGNMEQ ::= "=:="
SEQ ::= "=="
AUGSEQ ::= "==:="
EQUIV ::= "==="
AUGEQUIV ::= "===:="
NMGT ::= ">"
AUGNMGT ::= ">:="
NMGE ::= ">="
AUGNMGE ::= ">=:="
SGT ::= ">>"
AUGSGT ::= ">>:="
SGE ::= ">>="
AUGSGE ::= ">>=:="
QMARK ::= "?"
AUGQMARK ::= "?:="
AT ::= "@"
AUGAT ::= "@:="
BACKSLASH ::= "\\"
CARET ::= "^"
AUGCARET ::= "^:="
BAR ::= "|"
CONCAT ::= "||"
AUGCONCAT ::= "||:="
LCONCAT ::= "|||"
AUGLCONCAT ::= "|||:="
TILDE ::= "~"
NMNE ::= "~="
AUGNMNE ::= "~=:="
SNE ::= "~=="
AUGSNE ::= "~==:="
NEQUIV ::= "~==="
AUGNEQUIV ::= "~===:="
LPAREN ::= "("
RPAREN ::= ")"
PCOLON ::= "+:"
COMMA ::= ","
MCOLON ::= "-:"
COLON ::= ":"
SEMICOL ::= ";"
LBRACK ::= "["
RBRACK ::= "]"
LBRACE ::= "{"
RBRACE ::= "}"