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PollRobots/peg-3-pegOfPeg.ex.fs

Last active December 12, 2015 01:18
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peg-3-pegOfPeg.ex.fs
// unary <- ([!&] unary) / (atom [*+?])?
let parseUnary _ = function
| Production [TerminalSymbol "!"; Parsed x] -> Parsed <| Not x
| Production [TerminalSymbol "&"; Parsed x] -> Parsed <| And x
| Production [Parsed x; TerminalSymbol "*"] -> Parsed <| ZeroOrMore x
| Production [Parsed x; TerminalSymbol "+"] -> Parsed <| OneOrMore x
| Production [Parsed x; TerminalSymbol "?"] -> Parsed <| Optional x
| Production [Parsed _ as x; EmptyMatch] -> x
| x -> unexpected x
let unaryRule = GrammarRule<Expression>(Choice [Sequence [TerminalOneOf "!&"; NonTerminal "unary"];
Sequence [NonTerminal "atom"; Optional(TerminalOneOf "*+?")]], parseUnary)
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