Rc2Parser

An Rmd parser based on Antlr 4.

Building ANTLR4 files from grammar

• The antlr jar must be in your classpath
• java -Xmx500M org.antlr.v4.Tool -Dlanguage=Swift -o Sources/Rc2Parser/generated -visitor *.g4

Generator Error

For some reason, RFilter.eat will generate the lines (aprox line 333) try match(RFilter.Tokens.NL.rawValue) let token = _localctx.castdown(EatContext.self) as! WritableToken

which is incorrect as self will never be a writable token. The result of match, howver, will. let token = try match(RFilter.Tokens.NL.rawValue) as! WritableToken

RBaseListener needs throws added to enterEveryRule function

this change needs to be made everytime code is regeneratred.

Missing throw declarations

ParseTreeLiatener declares enter/exitEveryRule as throws. The generated listeners do not. A pull request has been sumbitted to antlr. Until then,

Testing

copy test1.Rmd to /tmp