ottparse-pretty 0.1.2.2 → 0.1.2.3

raw patch · 3 files changed

+83/−1 lines, 3 files

Files

• CHANGES +5/−0
• ottparse-pretty.cabal +2/−1
• src/Text/Ott/Pretty.hs +76/−0

@@ -1,3 +1,8 @@+* 0.1.2.3: 12 Oct 2012++  - add Text.Ott.Pretty to other-modules field so it gets included+    in the tarball+ * 0.1.2.2: 21 Aug 2012    - bump upper bound on base to <4.7 and split to <0.3

@@ -1,5 +1,5 @@ Name:                ottparse-pretty-Version:             0.1.2.2+Version:             0.1.2.3 Synopsis:            Pretty-printer for Ott parse trees Description:         Ott (<http://www.cl.cam.ac.uk/~pes20/ott/>) is a tool for 		     writing formal definitions of programming@@ -36,3 +36,4 @@                      parsec >= 3.0 && < 3.2,                      containers >= 0.3 && < 0.6,                      uniplate >= 1.6 && < 1.7+  Other-modules:     Text.Ott.Pretty

@@ -0,0 +1,76 @@+-----------------------------------------------------------------------------+-- |+-- Module      :  Text.Ott.Pretty+-- Copyright   :  (c) Brent Yorgey 2011+-- License     :  BSD-style (see LICENSE)+-- Maintainer  :  Brent Yorgey <byorgey@cis.upenn.edu>+-- Stability   :  experimental+--+-- Ott (<http://www.cl.cam.ac.uk/~pes20/ott/>) is a tool for writing+-- formal definitions of programming languages and calculi.  Often the+-- Ott grammars one defines end up being ambiguous, and Ott signals+-- its displeasure by spewing forth several massive parse trees in a+-- format requiring formidable patience to read.  Finding the slight+-- differences between two such parse trees is an exercise in+-- seizure-inducing tedium.+--+-- To the rescue comes ottparse-pretty!  Simply paste in each parse+-- and it is shown to you in a nicely formatted tree form with all the+-- extra meaningless cruft removed.+--+-- This module implements the internals of the tool: a simple parser+-- and a set of tree transformations.+-----------------------------------------------------------------------------+module Text.Ott.Pretty where++import Text.Parsec+import Control.Applicative ((<$>), (<*>), (*>), (<*), pure)++import Data.Tree+import Data.List.Split++import Data.Generics.Uniplate.Data+++type Parser a = Parsec String () a++type T = Tree String++-- | Parse a string dump of an Ott parse tree.+parseTree :: Parser T+parseTree = char '(' *> parseApp <* char ')' <* spaces+        <|> Node <$> parseId <*> pure [] <* spaces++-- | Parse an application, i.e. a parent node with one or more children.+parseApp :: Parser T+parseApp = Node <$> parseId <*> many1 parseTree++-- | Parse an identifier.+parseId :: Parser String+parseId = spaces *> many1 (alphaNum <|> char '_' <|> char ':' <|> char '\'') <* spaces++-- | \"Normalize\" a parse tree by deleting meaningless cruft.+normalizeTree :: T -> T+normalizeTree = transformBis [ [ transformer stripColonNames ]+                             , [ transformer deleteSteSt ]+                             , [ transformer deleteNonterm ]+                             , [ transformer replaceStNode ]+                             ]++deleteSteSt :: T -> T+deleteSteSt (Node "Ste_st" [c]) = c+deleteSteSt t = t++deleteNonterm :: T -> T+deleteNonterm (Node "St_nonterm" [n@(Node _ [])]) = n+deleteNonterm t = t++replaceStNode :: T -> T+replaceStNode (Node "St_node" (Node name [] : cs)) = Node name cs+replaceStNode t = t++stripColonNames :: T -> T+stripColonNames (Node s cs) =+  case split (dropDelims . dropBlanks $ onSublist ":") s of+    [_,n] -> Node n cs+    _     -> Node s cs