andre
Effective Haskell:Chapter 13 (B9 - PDF version) - infinite loop when running the ClassyArchiver code
Refer to pages 508-511
I get an infinite loop when running the original parseArchive function, after adding a variable called "archiveDef, which codifies the example given on p.491.
archiveDef :: Text
archiveDef = Text.unlines $
[ "archive \"example.archive\":"
, ""
, "import \"./extras/example1.txt\""
, ""
, "new-file \"inline-example.txt\":"
, " this is some text"
, " it can have newlines"
, " but it needs to be indented"
, ""
, "import \"./extras/example2.txt\""
]
λ> runArchiver archiveDef parseArchive
I’ve changed the parseArchive function by removing “parseBlock”.
I commented out the original line and added the modification under it.
parseArchive :: Archiver Archive
parseArchive = do
expectText "archive"
dropSpaces
archiveName <- quotedString
expectText ":\n"
-- files <- parseBlock parseArchiveStatements
files <- parseArchiveStatements -- CHANGE HERE
pure $ Archive archiveName files
The infinite loop disappears when using this modified version.
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