pegged.parser

# This is the PEG extended grammar used by Pegged Pegged:

# Syntactic rules: Grammar <- Spacing GrammarName Definition+ :eoi Definition <- LhsName Arrow Expression Expression <- FirstExpression / LongestExpression FirstExpression <- :OR? Sequence (:OR Sequence)+ LongestExpression <- :(OR / LONGEST_OR)? Sequence (:LONGEST_OR Sequence)* Sequence <- Prefix+ Prefix <- (POS / NEG / FUSE / DISCARD / KEEP / DROP / PROPAGATE)* Suffix Suffix <- Primary (OPTION / ZEROORMORE / ONEORMORE / Action)* Primary <- !(LhsName Arrow) ( RhsName / :OPEN Expression :CLOSE / Literal / CILiteral / CharClass / ANY) # Lexical syntax Identifier <- identifier GrammarName <- Identifier ParamList? Spacing :':' Spacing LhsName <- Identifier ParamList? Spacing RhsName <- Identifier ArgList? (NAMESEP Identifier ArgList?)* Spacing # NAMESEP is *not* discarded ParamList <- :OPEN Param (:SEPARATOR Param)* :CLOSE Param <- DefaultParam / SingleParam DefaultParam <- Identifier Spacing :ASSIGN Expression SingleParam <- Identifier Spacing ArgList <- :OPEN Expression (:SEPARATOR Expression)* :CLOSE

Literal <- quote ~(!quote Char)* quote !'i' Spacing / doublequote ~(!doublequote Char)* doublequote !'i' Spacing CILiteral <- quote ~(!quote Char)* quote :'i' Spacing / doublequote ~(!doublequote Char)* doublequote :'i' Spacing CharClass <- :'[' (!']' CharRange)* :']' Spacing CharRange <- Char '-' Char / Char

# Terminals Char <~ backslash ( quote / doublequote / backquote / backslash / '-' / '[' / ']' / nrt / [0-2][0-7][0-7] / [0-7][0-7]? / 'x' hexDigit hexDigit / 'u' hexDigit hexDigit hexDigit hexDigit / 'U' hexDigit hexDigit hexDigit hexDigit hexDigit hexDigit hexDigit hexDigit ) / . # or anything else

Arrow <- LEFTARROW / FUSEARROW / DISCARDARROW / KEEPARROW / DROPARROW / PROPAGATEARROW / ACTIONARROW / SPACEARROW LEFTARROW <- '<-' Spacing FUSEARROW <- '<~' Spacing DISCARDARROW <- '<:' Spacing KEEPARROW <- '<^' Spacing DROPARROW <- '<;' Spacing PROPAGATEARROW <- '<%' Spacing SPACEARROW <- '<' Spacing ACTIONARROW <- '<' Action Spacing

OR <- '/' Spacing LONGEST_OR <- '|' Spacing

POS <- '&' Spacing NEG <- '!' Spacing FUSE <- '~' Spacing DISCARD <- ':' Spacing KEEP <- '^' Spacing DROP <- ';' Spacing PROPAGATE <- '%' Spacing

OPTION <- '?' Spacing ZEROORMORE <- '*' Spacing ONEORMORE <- '+' Spacing ACTIONOPEN <- '{' Spacing ACTIONCLOSE <- '}' Spacing SEPARATOR <- ',' Spacing ASSIGN <- '=' Spacing NAMESEP <- '.' # No Spacing OPEN <- '(' Spacing CLOSE <- ')' Spacing ANY <- '.' Spacing Spacing <: (blank / Comment)* Comment <- '#' (!eol .)* :eol Space <- spacing / "\\t" / "\\n" / "\\r"

# Action Rule Action <- :ACTIONOPEN Spacing ((Lambda / qualifiedIdentifier) (:SEPARATOR (Lambda / qualifiedIdentifier))*) Spacing :ACTIONCLOSE Lambda <~ (!(ACTIONCLOSE/SEPARATOR) (LambdaItems / NestedList('{',LambdaItems,'}') / .))*

LambdaItems <- ~DComment / ~DString / ~DParamList DString <- WYSString / DBQString / TKNString / DLMString

WYSString <- 'r' doublequote (!doublequote .)* doublequote / backquote (!backquote .)* backquote

DBQString <- doublequote (!doublequote Char)* doublequote

TKNString <- (&'q{' ('q' NestedList('{',DString,'}')))

DLMString <- ('q' doublequote) ( (&'{' NestedList('{',DString,'}')) / (&'[' NestedList('[',DString,']')) / (&'(' NestedList('(',DString,')')) / (&'<' NestedList('<',DString,'>')) ) doublequote

DComment <- DLineComment / DBlockComment / DNestingBlockComment

DLineComment <- "//" (!endOfLine .)* endOfLine DBlockComment <- "/*" (!"*/" .)* "*/" DNestingBlockComment <- NestedList("/+","+/")

DParamList <- NestedList('(',')')

# Linear nested lists with and without special items NestedList(L,Items,R) <- ^L ( !(L/R/Items) . )* ( Items / NestedList(L,Items,R) / ( !(L/R/Items) . )* )* ( !(L/R/Items) . )* ^R

NestedList(L,R) <- ^L ( !(L/R) . )* (NestedList(L,R) / ( !(L/R) . )*)* ( !(L/R) . )* ^R