# This is a [Parser Tools] peg grammar for an [ISBL] like language # # This peg parser has special annotations in the comments on the # right to associate the rules with template actions that will # be evaluated when the AST of the recognosed text is executed. # # Procedures (or methods) for rules without annotations are provided # for each rule individualy. # PEG isblparser (Phrase) Phrase <- WS Assign WS EOF / WS TopExpr WS EOF ; # action eval TopExpr <- RelExpr ; RelValue<- "(" WS RelExpr WS ")" / Table ; # action eval leaf: Table <- Ident ; RelExpr <- Sum ; # action eval ProjOp <- "%" ; # action token Tupple <- ProjOp WS Cols ; void: MapOp <- "->" / "as" ; leaf: Column <- Ident ; # action token Project <- Tupple / RelValue WS (ProjOp WS Cols)* ; Cols <- Col WS (","? WS Col)* ; Col <- CFunc / CMap / "!" WS CDel / CName / CAll ; CFunc <- Name WS "(" WS InArgs? WS "|" WS OutArgs WS ")" WS ; leaf: InArgs<- ( Value WS ("," WS Value)* ) ? ; # action token leaf: OutArgs<- Name WS ("," WS Name)* ; # action token leaf: CName <- Ident ; CMap <- Expr WS MapOp WS Column ; leaf: CDel <- Ident ; leaf: CAll <- "*" ; SelOp <- ":" ; # action token Select <- Project WS (SelOp WS SelExpr)* ; leaf: SelExpr <- Expr ; # action token JoinOp <- "*" ; # action token Join <- Select WS (JoinOp WS Select)* ; SumOp <- "+" / "-" / "." ; # action token Sum <- Join WS (SumOp WS Join)* ; AssOp <- "=" / "+=" / "-=" / ":=" ; # action token SetOp <- "*=" ; # action token Assign <- Table WS SetOp WS RelExpr WS "set" WS AssList / Table WS AssOp WS RelExpr ; AssList<- Update WS (Comma WS AssCol ) ? ; # action eval Update <- Name WS Equ WS Value ; # action eval Comma <- "," ; # action token Equ <- "=" ; # action token RP <- "(" ; # action token LP <- ")" ; # action token # These rules are elaborated to enable future tracking of # the data type of scaler expressions, but that is not # implimented yet. # leaf: VName <- Ident ; Value <- RP WS Expr WS LP / Func / NULL / Real / Int / String / VName ; # action eval leaf: Func <- Name RP Args? LP ; # action token Args <- Expr ("," Expr)* ; # action eval StrOp <- "||" ; # action token StrExpr <- Value WS (StrOp WS Value)* ; # action eval MulOp <- "*" / "/" / "%" ; # action token MulExpr <- StrExpr WS (MulOp WS StrExpr)* ; # action eval AddOp <- "+" / "-" ; # action token AddExpr <- MulExpr WS (AddOp WS MulExpr)* ; # action eval BitOp <- "<<" / ">>" / "&" / "|" ; # action token BitExpr <- AddExpr WS (BitOp WS AddExpr)* ; # action eval CmpOp <- "<" / "<=" / ">" / ">=" "=" / "==" / "!=" / "<>" "IS" / "IS NOT" / "IN" / "LIKE" "is" / "is not" / "in" / "like" "GLOB" / "MATCH" / "REGEXP" "glob" / "match" / "regexp" ; # action token CmpExpr <- BitExpr WS (CmpOp WS BitExpr)* ; # action eval AndOp <- "AND" / "and" ; # action token AndExpr <- CmpExpr WS (AndOp WS CmpExpr)* ; # action eval OrOp <- "OR" / "or" ; # action token OrExpr <- AndExpr WS ( OrOp WS AndExpr)* ; # action eval Expr <- OrExpr ; # action eval void: WS <- * ; leaf: String <- '"' (!'"' .)* '"' / "'" (!'"' .)* "'" ; NULL <- "NULL" ; # action token leaf: Name <- Ident ; # action token Number <- Real / Int ; Real <- Sign? (+)? Frac ; Int <- Sign? + ; Sign <- '+' / '-' ; Frac <- '.' * ; Ident <- [_A-Za-z0-9]* ; EOF <- !. ; END;