Merge pull request #45 from osvita-io/oleks-clarify-parser-impl-disti…

…nction

Clarify relation between Parser and Parser.Impl(Mega)parsec

remarks.cabal

@@ -32,7 +32,7 @@ library
                      , Invalid
                      , MergeAsts
                      , Parser
-                     , Parser.ImplParsec
+                     , Parser.ImplMegaparsec
                      , Pending
                      , PointsChecker
                      , PrettyPrinter

src/Parser.hs

@@ -1,11 +1,22 @@
+{-|
+
+A wrapper module, exposing the main parsing types and functions.
+
+For a concrete implementation, see "Parser.ImplMegaparsec".
+
+This wrapping allows to both treat the parser as a black box (e.g.,
+[Parser.BlackBoxTests](https://github.com/DIKU-EDU/remarks/blob/master/test/Parser/BlackBoxTests.hs)),
+as well as import and use (i.e., test or debug)
+implementation-specific details.
+
+-}
 module Parser
   ( ParseError
   , parseString
   , parseFile
   ) where
 
-import Parser.ImplParsec
--- import Parser.Impl
+import Parser.ImplMegaparsec
   ( ParseError
   , parseString
   , parseFile

src/Parser/ImplParsec.hs → src/Parser/ImplMegaparsec.hs

@@ -1,6 +1,15 @@
 {-# LANGUAGE DeriveGeneric #-}
 
-module Parser.ImplParsec (parseString, parseFile, ParseError) where
+{-|
+
+An implementation of "Parser" using
+[megaparsec](https://hackage.haskell.org/package/megaparsec).
+
+The module declaration does not limit its exports to enable white-box
+testing and debugging.
+
+-}
+module Parser.ImplMegaparsec where
 
 import Ast
 import Config