Merge branch 'master' into pretty-print-expectations

# Conflicts: # script/cibuild-semantic-diff # script/cibuild-semantic-diff-linux # test/RangeSpec.hs # test/Spec.hs
2024-12-25 07:55:12 +03:00 · 2016-09-20 05:56:12 +09:00 · 2016-09-20 05:56:12 +09:00 · 8cec95aad4
commit 8cec95aad4
parent 5e3583240b 68cf915836
29 changed files with 198 additions and 99 deletions
--- a/semantic-diff.cabal
+++ b/semantic-diff.cabal
@ -24,7 +24,6 @@ library
                     , Data.Record
                     , Data.Mergeable
                     , Data.Mergeable.Generic
-                     , Data.These.Arbitrary
                     , Diff
                     , Diff.Arbitrary
                     , Diffing
@ -33,6 +32,7 @@ library
                     , Language
                     , Language.C
                     , Language.JavaScript
+                     , Language.Markdown
                     , Parser
                     , Patch
                     , Patch.Arbitrary
@ -59,6 +59,7 @@ library
                     , blaze-html
                     , blaze-markup
                     , bytestring
+                     , cmark
                     , containers
                     , directory
                     , dlist
@ -84,7 +85,7 @@ library
                     , quickcheck-instances
  default-language:    Haskell2010
  default-extensions:  DeriveFunctor, DeriveFoldable, DeriveTraversable, DeriveGeneric, FlexibleContexts, FlexibleInstances, OverloadedStrings, NoImplicitPrelude, RecordWildCards, LambdaCase
-  ghc-options:        -Wall -fno-warn-name-shadowing -O2 -threaded -fprof-auto "-with-rtsopts=-N -p -s -h -i0.1" -j
+  ghc-options:        -Wall -fno-warn-name-shadowing -O2 -fprof-auto -j

 benchmark semantic-diff-bench
  type:                exitcode-stdio-1.0
@ -114,6 +115,8 @@ test-suite test
                     , DiffSummarySpec
                     , InterpreterSpec
                     , PatchOutputSpec
+                     , RangeSpec
+                     , Source.Spec
                     , TermSpec
  build-depends:       base
                     , bifunctors
--- a/src/Alignment.hs
+++ b/src/Alignment.hs
@ -24,7 +24,7 @@ import Info
 import Patch
 import Prologue hiding (fst, snd)
 import Range
-import Source hiding (break, fromList, uncons, (++))
+import Source hiding (break, fromList, uncons)
 import SplitDiff
 import Syntax
 import Term
@ -38,7 +38,7 @@ numberedRows = countUp (both 1 1)
        nextLineNumbers from row = modifyJoin (fromThese identity identity) (succ <$ row) <*> from

 -- | Determine whether a line contains any patches.
-hasChanges :: (Prologue.Foldable f, Functor f) => SplitDiff f annotation -> Bool
+hasChanges :: (Foldable f, Functor f) => SplitDiff f annotation -> Bool
 hasChanges = or . (True <$)

 -- | Align a Diff into a list of Join These SplitDiffs representing the (possibly blank) lines on either side.
--- a/src/Category.hs
+++ b/src/Category.hs
@ -16,8 +16,8 @@ data Category
  | Boolean
  -- | A bitwise operator.
  | BitwiseOperator
-  -- | An operator with 2 operands.
-  | BinaryOperator
+  -- | A boolean operator (e.g. ||, &&).
+  | BooleanOperator
  -- | A literal key-value data structure.
  | DictionaryLiteral
  -- | A pair, e.g. of a key & value
@ -104,6 +104,8 @@ data Category
  | RelationalOperator
  -- | An empty statement. (e.g. ; in JavaScript)
  | Empty
+  -- | A mathematical operator (e.g. +, -, *, /).
+  | MathOperator
  deriving (Eq, Generic, Ord, Show)

 -- Instances
@ -115,7 +117,8 @@ instance Arbitrary Category where
      pure Program
    , pure Error
    , pure Boolean
-    , pure BinaryOperator
+    , pure BooleanOperator
+    , pure MathOperator
    , pure DictionaryLiteral
    , pure Pair
    , pure FunctionCall
--- a/src/Data/Bifunctor/Join/Arbitrary.hs
+++ b/src/Data/Bifunctor/Join/Arbitrary.hs
@ -4,7 +4,6 @@ module Data.Bifunctor.Join.Arbitrary where
 import Data.Bifunctor.Join
 import Data.Functor.Both as Both
 import Data.These
-import Data.These.Arbitrary ()
 import Prologue
 import Test.QuickCheck

--- a/src/Data/Functor/Both.hs
+++ b/src/Data/Functor/Both.hs
@ -24,6 +24,10 @@ fst = Prologue.fst . runJoin
 snd :: Both a -> a
 snd = Prologue.snd . runJoin

-instance Monoid a => Monoid (Join (,) a) where
+instance (Semigroup a, Monoid a) => Monoid (Join (,) a) where
  mempty = pure mempty
-  mappend a b = mappend <$> a <*> b
+  mappend = (<>)
+
+
+instance (Semigroup a) => Semigroup (Join (,) a) where
+  a <> b = Join $ runJoin a <> runJoin b
--- a/src/Data/RandomWalkSimilarity.hs
+++ b/src/Data/RandomWalkSimilarity.hs
@ -32,7 +32,7 @@ import Test.QuickCheck hiding (Fixed)
 import Test.QuickCheck.Random

 -- | Given a function comparing two terms recursively, and a function to compute a Hashable label from an unpacked term, compute the diff of a pair of lists of terms using a random walk similarity metric, which completes in log-linear time. This implementation is based on the paper [_RWS-Diff—Flexible and Efficient Change Detection in Hierarchical Data_](https://github.com/github/semantic-diff/files/325837/RWS-Diff.Flexible.and.Efficient.Change.Detection.in.Hierarchical.Data.pdf).
-rws :: forall f fields. (Eq (Record fields), Prologue.Foldable f, Functor f, Eq (f (Cofree f (Record fields))), HasField fields (Vector.Vector Double))
+rws :: forall f fields. (Foldable f, Functor f, HasField fields (Vector.Vector Double))
  => (Cofree f (Record fields) -> Cofree f (Record fields) -> Maybe (Free (CofreeF f (Both (Record fields))) (Patch (Cofree f (Record fields))))) -- ^ A function which compares a pair of terms recursively, returning 'Just' their diffed value if appropriate, or 'Nothing' if they should not be compared.
  -> [Cofree f (Record fields)] -- ^ The list of old terms.
  -> [Cofree f (Record fields)] -- ^ The list of new terms.
@ -83,7 +83,7 @@ rws compare as bs
        deleteRemaining diffs (_, unmappedA, _) = foldl' (flip (List.insertBy (comparing fst))) diffs ((termIndex &&& deleting . term) <$> unmappedA)

 -- | Computes a constant-time approximation to the edit distance of a diff. This is done by comparing at most _m_ nodes, & assuming the rest are zero-cost.
-editDistanceUpTo :: (Prologue.Foldable f, Functor f) => Integer -> Free (CofreeF f (Both a)) (Patch (Cofree f a)) -> Int
+editDistanceUpTo :: (Foldable f, Functor f) => Integer -> Free (CofreeF f (Both a)) (Patch (Cofree f a)) -> Int
 editDistanceUpTo m = diffSum (patchSum termSize) . cutoff m
  where diffSum patchCost diff = sum $ fmap (maybe 0 patchCost) diff

--- a/src/Data/These/Arbitrary.hs
+++ b/src/Data/These/Arbitrary.hs
@ -1,12 +0,0 @@
-{-# OPTIONS_GHC -fno-warn-orphans #-}
-module Data.These.Arbitrary where
-
-import Data.These
-import Prologue
-import Test.QuickCheck
-
-instance (Arbitrary a, Arbitrary b) => Arbitrary (These a b) where
-  arbitrary = oneof [ This <$> arbitrary
-                    , That <$> arbitrary
-                    , These <$> arbitrary <*> arbitrary ]
-  shrink = these (fmap This . shrink) (fmap That . shrink) (\ a b -> (This <$> shrink a) ++ (That <$> shrink b) ++ (These <$> shrink a <*> shrink b))
--- a/src/Diff.hs
+++ b/src/Diff.hs
@ -19,26 +19,26 @@ type SyntaxDiff leaf fields = Diff (Syntax leaf) (Record fields)


 type instance Base (Free f a) = FreeF f a
-instance Functor f => Foldable.Foldable (Free f a) where project = runFree
-instance Functor f => Foldable.Unfoldable (Free f a) where embed = free
+instance Functor f => Recursive (Free f a) where project = runFree
+instance Functor f => Corecursive (Free f a) where embed = free

-diffSum :: (Prologue.Foldable f, Functor f) => (Patch (Term f annotation) -> Int) -> Diff f annotation -> Int
+diffSum :: (Foldable f, Functor f) => (Patch (Term f annotation) -> Int) -> Diff f annotation -> Int
 diffSum patchCost diff = sum $ fmap patchCost diff

 -- | The sum of the node count of the diff’s patches.
-diffCost :: (Prologue.Foldable f, Functor f) => Diff f annotation -> Int
+diffCost :: (Foldable f, Functor f) => Diff f annotation -> Int
 diffCost = diffSum $ patchSum termSize

 -- | Merge a diff using a function to provide the Term (in Maybe, to simplify recovery of the before/after state) for every Patch.
-mergeMaybe :: (Functor f, Mergeable f) => (Patch (Term f annotation) -> Maybe (Term f annotation)) -> Diff f annotation -> Maybe (Term f annotation)
+mergeMaybe :: Mergeable f => (Patch (Term f annotation) -> Maybe (Term f annotation)) -> Diff f annotation -> Maybe (Term f annotation)
 mergeMaybe transform = iter algebra . fmap transform
  where algebra :: Mergeable f => TermF f (Both annotation) (Maybe (Term f annotation)) -> Maybe (Term f annotation)
        algebra (annotations :< syntax) = cofree . (Both.fst annotations :<) <$> sequenceAlt syntax

 -- | Recover the before state of a diff.
-beforeTerm :: (Functor f, Mergeable f) => Diff f annotation -> Maybe (Term f annotation)
+beforeTerm :: Mergeable f => Diff f annotation -> Maybe (Term f annotation)
 beforeTerm = mergeMaybe before

 -- | Recover the after state of a diff.
-afterTerm :: (Functor f, Mergeable f) => Diff f annotation -> Maybe (Term f annotation)
+afterTerm :: Mergeable f => Diff f annotation -> Maybe (Term f annotation)
 afterTerm = mergeMaybe after
--- a/src/DiffSummary.hs
+++ b/src/DiffSummary.hs
@ -24,7 +24,7 @@ import Source

 data Identifiable a = Identifiable a | Unidentifiable a

-identifiable :: (HasCategory leaf, HasField fields Category, HasField fields Range) => SyntaxTerm leaf fields -> Identifiable (SyntaxTerm leaf fields)
+identifiable :: SyntaxTerm leaf fields -> Identifiable (SyntaxTerm leaf fields)
 identifiable term = isIdentifiable (unwrap term) $ term
  where isIdentifiable = \case
          S.FunctionCall{} -> Identifiable
@ -161,14 +161,14 @@ toTermName source term = case unwrap term of
        termNameFromSource term = termNameFromRange (range term)
        termNameFromRange range = toText $ Source.slice range source
        range = characterRange . extract
-        toArgName :: (HasCategory leaf, HasField fields Category, HasField fields Range) => SyntaxTerm leaf fields -> Text
+        toArgName :: SyntaxTerm leaf fields -> Text
        toArgName arg = case identifiable arg of
                          Identifiable arg -> toTermName' arg
                          Unidentifiable _ -> "…"

 maybeParentContext :: Maybe (Category, Text) -> Doc
 maybeParentContext = maybe "" (\annotation ->
-  space <> "in the" <+> (toDoc $ snd annotation) <+> toDoc (toCategoryName $ fst annotation))
+  space P.<> "in the" <+> (toDoc $ snd annotation) <+> toDoc (toCategoryName $ fst annotation))

 toDoc :: Text -> Doc
 toDoc = string . toS
@ -221,7 +221,8 @@ instance HasCategory Text where
 instance HasCategory Category where
  toCategoryName = \case
    ArrayLiteral -> "array"
-    BinaryOperator -> "binary operator"
+    BooleanOperator -> "boolean operator"
+    MathOperator -> "math operator"
    BitwiseOperator -> "bitwise operator"
    RelationalOperator -> "relational operator"
    Boolean -> "boolean"
@ -241,7 +242,7 @@ instance HasCategory Category where
    C.Case -> "case statement"
    C.SubscriptAccess -> "subscript access"
    C.MathAssignment -> "math assignment"
-    C.Ternary -> "ternary"
+    C.Ternary -> "ternary expression"
    C.Operator -> "operator"
    Identifier -> "identifier"
    IntegerLiteral -> "integer"
@ -269,18 +270,18 @@ instance HasCategory Category where
    C.CommaOperator -> "comma operator"
    C.Empty -> "empty statement"

-instance (HasCategory leaf, HasField fields Category) => HasCategory (SyntaxTerm leaf fields) where
+instance HasField fields Category => HasCategory (SyntaxTerm leaf fields) where
  toCategoryName = toCategoryName . category . extract

 instance Arbitrary Branch where
  arbitrary = oneof [ pure BIndexed, pure BFixed ]
  shrink = genericShrink

-instance (Eq a, Arbitrary a) => Arbitrary (DiffSummary a) where
+instance Arbitrary a => Arbitrary (DiffSummary a) where
  arbitrary = DiffSummary <$> arbitrary <*> arbitrary
  shrink = genericShrink

 instance P.Pretty DiffInfo where
  pretty LeafInfo{..} = squotes (string $ toSL termName) <+> (string $ toSL categoryName)
-  pretty BranchInfo{..} = mconcat $ punctuate (string "," <> space) (pretty <$> branches)
+  pretty BranchInfo{..} = mconcat $ punctuate (string "," P.<> space) (pretty <$> branches)
  pretty ErrorInfo{..} = squotes (string $ toSL termName) <+> "at" <+> (string . toSL $ displayStartEndPos errorSpan) <+> "in" <+> (string . toSL $ spanName errorSpan)
--- a/src/Diffing.hs
+++ b/src/Diffing.hs
@ -1,8 +1,8 @@
 {-# LANGUAGE DataKinds, RankNTypes, TypeOperators #-}
 module Diffing where

-import qualified Prologue
 import Prologue hiding (fst, snd)
+import Category
 import qualified Data.ByteString.Char8 as B1
 import Data.Functor.Both
 import Data.Functor.Foldable
@ -18,6 +18,7 @@ import Diff
 import Info
 import Interpreter
 import Language
+import Language.Markdown
 import Parser
 import Patch
 import Range
@ -26,7 +27,7 @@ import Renderer.JSON
 import Renderer.Patch
 import Renderer.Split
 import Renderer.Summary
-import Source hiding ((++))
+import Source
 import Syntax
 import System.Directory
 import System.FilePath
@ -35,7 +36,6 @@ import Term
 import TreeSitter
 import Text.Parser.TreeSitter.Language
 import qualified Data.Text as T
-import Category
 import Data.Aeson (toJSON, toEncoding)
 import Data.Aeson.Encoding (encodingToLazyByteString)

@ -43,7 +43,7 @@ import Data.Aeson.Encoding (encodingToLazyByteString)
 -- | result.
 -- | Returns the rendered result strictly, so it's always fully evaluated
 -- | with respect to other IO actions.
-diffFiles :: (HasField fields Category, HasField fields Cost, HasField fields Range, Eq (Record fields)) => Parser (Syntax Text) (Record fields) -> Renderer (Record (Vector.Vector Double ': fields)) -> Both SourceBlob -> IO Output
+diffFiles :: (HasField fields Category, HasField fields Cost) => Parser (Syntax Text) (Record fields) -> Renderer (Record (Vector.Vector Double ': fields)) -> Both SourceBlob -> IO Output
 diffFiles parser renderer sourceBlobs = do
  terms <- traverse (fmap (defaultFeatureVectorDecorator getLabel) . parser) sourceBlobs

@ -70,6 +70,7 @@ parserForType :: Text -> Parser (Syntax Text) (Record '[Range, Category])
 parserForType mediaType = case languageForType mediaType of
  Just C -> treeSitterParser C ts_language_c
  Just JavaScript -> treeSitterParser JavaScript ts_language_javascript
+  Just Markdown -> cmarkParser
  Just Ruby -> treeSitterParser Ruby ts_language_ruby
  _ -> lineByLineParser

@ -129,7 +130,7 @@ decorateTerm :: Functor f => TermDecorator f fields field -> Cofree f (Record fi
 decorateTerm decorator = cata $ \ c -> cofree ((decorator (extract <$> c) .: headF c) :< tailF c)

 -- | Term decorator computing the cost of an unpacked term.
-termCostDecorator :: (Prologue.Foldable f, Functor f) => TermDecorator f a Cost
+termCostDecorator :: (Foldable f, Functor f) => TermDecorator f a Cost
 termCostDecorator c = 1 + sum (cost <$> tailF c)

 -- | Determine whether two terms are comparable based on the equality of their categories.
@ -143,7 +144,7 @@ diffCostWithCachedTermCosts diff = unCost $ case runFree diff of
  Pure patch -> sum (cost . extract <$> patch)

 -- | Returns a rendered diff given a parser, diff arguments and two source blobs.
-textDiff :: (Eq (Record fields), HasField fields Category, HasField fields Cost, HasField fields Range) => Parser (Syntax Text) (Record fields) -> DiffArguments -> Both SourceBlob -> IO Output
+textDiff :: (HasField fields Category, HasField fields Cost, HasField fields Range) => Parser (Syntax Text) (Record fields) -> DiffArguments -> Both SourceBlob -> IO Output
 textDiff parser arguments = diffFiles parser $ case format arguments of
  Split -> split
  Patch -> patch
@ -159,7 +160,7 @@ truncatedDiff arguments sources = pure $ case format arguments of
  Summary -> SummaryOutput mempty

 -- | Prints a rendered diff to stdio or a filepath given a parser, diff arguments and two source blobs.
-printDiff :: (Eq (Record fields), HasField fields Category, HasField fields Cost, HasField fields Range) => Parser (Syntax Text) (Record fields) -> DiffArguments -> Both SourceBlob -> IO ()
+printDiff :: (HasField fields Category, HasField fields Cost, HasField fields Range) => Parser (Syntax Text) (Record fields) -> DiffArguments -> Both SourceBlob -> IO ()
 printDiff parser arguments sources = do
  rendered <- textDiff parser arguments sources
  let renderedText = case rendered of
--- a/src/Interpreter.hs
+++ b/src/Interpreter.hs
@ -25,7 +25,7 @@ type Comparable f annotation = Term f annotation -> Term f annotation -> Bool
 type DiffConstructor f annotation = TermF f (Both annotation) (Diff f annotation) -> Diff f annotation

 -- | Diff two terms recursively, given functions characterizing the diffing.
-diffTerms :: (Eq leaf, Eq (Record fields), HasField fields Category, HasField fields (Vector.Vector Double))
+diffTerms :: (Eq leaf, HasField fields Category, HasField fields (Vector.Vector Double))
  => DiffConstructor (Syntax leaf) (Record fields) -- ^ A function to wrap up & possibly annotate every produced diff.
  -> Comparable (Syntax leaf) (Record fields) -- ^ A function to determine whether or not two terms should even be compared.
  -> SES.Cost (SyntaxDiff leaf fields) -- ^ A function to compute the cost of a given diff node.
@ -35,7 +35,7 @@ diffTerms :: (Eq leaf, Eq (Record fields), HasField fields Category, HasField fi
 diffTerms construct comparable cost a b = fromMaybe (replacing a b) $ diffComparableTerms construct comparable cost a b

 -- | Diff two terms recursively, given functions characterizing the diffing. If the terms are incomparable, returns 'Nothing'.
-diffComparableTerms :: (Eq leaf, Eq (Record fields), HasField fields Category, HasField fields (Vector.Vector Double)) => DiffConstructor (Syntax leaf) (Record fields) -> Comparable (Syntax leaf) (Record fields) -> SES.Cost (SyntaxDiff leaf fields) -> SyntaxTerm leaf fields -> SyntaxTerm leaf fields -> Maybe (SyntaxDiff leaf fields)
+diffComparableTerms :: (Eq leaf, HasField fields Category, HasField fields (Vector.Vector Double)) => DiffConstructor (Syntax leaf) (Record fields) -> Comparable (Syntax leaf) (Record fields) -> SES.Cost (SyntaxDiff leaf fields) -> SyntaxTerm leaf fields -> SyntaxTerm leaf fields -> Maybe (SyntaxDiff leaf fields)
 diffComparableTerms construct comparable cost = recur
  where recur a b
          | (category <$> a) == (category <$> b) = hylo construct runCofree <$> zipTerms a b
@ -71,7 +71,7 @@ algorithmWithTerms construct t1 t2 = case (unwrap t1, unwrap t2) of
        branch constructor a b = bySimilarity a b >>= annotate . constructor

 -- | Run an algorithm, given functions characterizing the evaluation.
-runAlgorithm :: (Functor f, GAlign f, Eq a, Eq (Record fields), Eq (f (Cofree f (Record fields))), Prologue.Foldable f, Traversable f, HasField fields (Vector.Vector Double))
+runAlgorithm :: (GAlign f, Traversable f, HasField fields (Vector.Vector Double))
  => (CofreeF f (Both (Record fields)) (Free (CofreeF f (Both (Record fields))) (Patch (Cofree f (Record fields)))) -> Free (CofreeF f (Both (Record fields))) (Patch (Cofree f (Record fields)))) -- ^ A function to wrap up & possibly annotate every produced diff.
  -> (Cofree f (Record fields) -> Cofree f (Record fields) -> Maybe (Free (CofreeF f (Both (Record fields))) (Patch (Cofree f (Record fields))))) -- ^ A function to diff two subterms recursively, if they are comparable, or else return 'Nothing'.
  -> SES.Cost (Free (CofreeF f (Both (Record fields))) (Patch (Cofree f (Record fields)))) -- ^ A function to compute the cost of a given diff node.
--- a/src/Language.hs
+++ b/src/Language.hs
@ -20,6 +20,7 @@ data Language =
    | HTML
    | Java
    | JavaScript
+    | Markdown
    | ObjectiveC
    | Perl
    | PHP
@ -35,6 +36,7 @@ languageForType mediaType = case mediaType of
    ".h" -> Just C
    ".c" -> Just C
    ".js" -> Just JavaScript
+    ".md" -> Just Markdown
    ".rb" -> Just Ruby
    _ -> Nothing

--- a/src/Language/JavaScript.hs
+++ b/src/Language/JavaScript.hs
@ -88,8 +88,8 @@ categoryForJavaScriptProductionName name = case name of
  "undefined" -> Identifier
  "arrow_function" -> Function
  "generator_function" -> Function
-  "math_op" -> BinaryOperator -- bitwise operator, e.g. +, -, *, /.
-  "bool_op" -> BinaryOperator -- boolean operator, e.g. ||, &&.
+  "math_op" -> MathOperator -- math operator, e.g. +, -, *, /.
+  "bool_op" -> BooleanOperator -- boolean operator, e.g. ||, &&.
  "comma_op" -> CommaOperator -- comma operator, e.g. expr1, expr2.
  "delete_op" -> Operator -- delete operator, e.g. delete x[2].
  "type_op" -> Operator -- type operator, e.g. typeof Object.
--- a/src/Language/Markdown.hs
+++ b/src/Language/Markdown.hs
@ -0,0 +1,38 @@
+{-# LANGUAGE DataKinds #-}
+module Language.Markdown where
+
+import CMark
+import Data.Record
+import Data.Text
+import Info
+import Parser
+import Prologue
+import Range
+import Source
+import SourceSpan
+import Syntax
+
+cmarkParser :: Parser (Syntax Text) (Record '[Range, Category])
+cmarkParser SourceBlob{..} = pure . toTerm (totalRange source) $ commonmarkToNode [ optSourcePos, optSafe ] (toText source)
+  where toTerm :: Range -> Node -> Cofree (Syntax Text) (Record '[Range, Category])
+        toTerm within (Node position t children) = let range = maybe within (sourceSpanToRange source . toSpan) position in cofree $ (range .: toCategory t .: RNil) :< case t of
+          -- Leaves
+          CODE text -> Leaf text
+          TEXT text -> Leaf text
+          CODE_BLOCK _ text -> Leaf text
+          -- Branches
+          _ -> Indexed (toTerm range <$> children)
+
+        toCategory :: NodeType -> Category
+        toCategory (TEXT _) = Other "text"
+        toCategory (CODE _) = Other "code"
+        toCategory (HTML_BLOCK _) = Other "html"
+        toCategory (HTML_INLINE _) = Other "html"
+        toCategory (HEADING _) = Other "heading"
+        toCategory (LIST (ListAttributes{..})) = Other $ case listType of
+          BULLET_LIST -> "unordered list"
+          ORDERED_LIST -> "ordered list"
+        toCategory (LINK{}) = Other "link"
+        toCategory (IMAGE{}) = Other "image"
+        toCategory t = Other (show t)
+        toSpan PosInfo{..} = SourceSpan "" (SourcePos (pred startLine) (pred startColumn)) (SourcePos (pred endLine) endColumn)
--- a/src/Prologue.hs
+++ b/src/Prologue.hs
@ -1,7 +1,6 @@
 module Prologue
 ( module X
 , lookup
-, traceShowId
 ) where

 import Protolude as X
@ -10,10 +9,3 @@ import Data.List (lookup)
 import Control.Comonad.Trans.Cofree as X
 import Control.Monad.Trans.Free as X
 import Control.Comonad as X
-
-import qualified GHC.Show as P
-import qualified Debug.Trace as T
-
-{-# WARNING traceShowId "'traceShowId' remains in code" #-}
-traceShowId :: P.Show a => a -> a
-traceShowId a = T.trace (P.show a) a
--- a/src/Renderer.hs
+++ b/src/Renderer.hs
@ -13,7 +13,7 @@ import Syntax
 -- | A function that will render a diff, given the two source blobs.
 type Renderer annotation = Both SourceBlob -> Diff (Syntax Text) annotation -> Output

-data DiffArguments = DiffArguments { format :: Format, output :: Maybe FilePath, outputPath :: FilePath }
+data DiffArguments = DiffArguments { format :: Format, output :: Maybe FilePath }
 deriving (Show)

 -- | The available types of diff rendering.
--- a/src/Renderer/Patch.hs
+++ b/src/Renderer/Patch.hs
@ -126,14 +126,14 @@ hunks diff blobs = hunksInRows (pure 1) $ alignDiff (source <$> blobs) diff

 -- | Given beginning line numbers, turn rows in a split diff into hunks in a
 -- | patch.
-hunksInRows :: (Prologue.Foldable f, Functor f) => Both (Sum Int) -> [Join These (SplitDiff f annotation)] -> [Hunk (SplitDiff f annotation)]
+hunksInRows :: (Foldable f, Functor f) => Both (Sum Int) -> [Join These (SplitDiff f annotation)] -> [Hunk (SplitDiff f annotation)]
 hunksInRows start rows = case nextHunk start rows of
  Nothing -> []
  Just (hunk, rest) -> hunk : hunksInRows (offset hunk <> hunkLength hunk) rest

 -- | Given beginning line numbers, return the next hunk and the remaining rows
 -- | of the split diff.
-nextHunk :: (Prologue.Foldable f, Functor f) => Both (Sum Int) -> [Join These (SplitDiff f annotation)] -> Maybe (Hunk (SplitDiff f annotation), [Join These (SplitDiff f annotation)])
+nextHunk :: (Foldable f, Functor f) => Both (Sum Int) -> [Join These (SplitDiff f annotation)] -> Maybe (Hunk (SplitDiff f annotation), [Join These (SplitDiff f annotation)])
 nextHunk start rows = case nextChange start rows of
  Nothing -> Nothing
  Just (offset, change, rest) -> let (changes, rest') = contiguousChanges rest in Just (Hunk offset (change : changes) $ take 3 rest', drop 3 rest')
@ -145,7 +145,7 @@ nextHunk start rows = case nextChange start rows of

 -- | Given beginning line numbers, return the number of lines to the next
 -- | the next change, and the remaining rows of the split diff.
-nextChange :: (Prologue.Foldable f, Functor f) => Both (Sum Int) -> [Join These (SplitDiff f annotation)] -> Maybe (Both (Sum Int), Change (SplitDiff f annotation), [Join These (SplitDiff f annotation)])
+nextChange :: (Foldable f, Functor f) => Both (Sum Int) -> [Join These (SplitDiff f annotation)] -> Maybe (Both (Sum Int), Change (SplitDiff f annotation), [Join These (SplitDiff f annotation)])
 nextChange start rows = case changeIncludingContext leadingContext afterLeadingContext of
  Nothing -> Nothing
  Just (change, afterChanges) -> Just (start <> mconcat (rowIncrement <$> skippedContext), change, afterChanges)
@ -155,12 +155,12 @@ nextChange start rows = case changeIncludingContext leadingContext afterLeadingC
 -- | Return a Change with the given context and the rows from the begginning of
 -- | the given rows that have changes, or Nothing if the first row has no
 -- | changes.
-changeIncludingContext :: (Prologue.Foldable f, Functor f) => [Join These (SplitDiff f annotation)] -> [Join These (SplitDiff f annotation)] -> Maybe (Change (SplitDiff f annotation), [Join These (SplitDiff f annotation)])
+changeIncludingContext :: (Foldable f, Functor f) => [Join These (SplitDiff f annotation)] -> [Join These (SplitDiff f annotation)] -> Maybe (Change (SplitDiff f annotation), [Join These (SplitDiff f annotation)])
 changeIncludingContext leadingContext rows = case changes of
  [] -> Nothing
  _ -> Just (Change leadingContext changes, afterChanges)
  where (changes, afterChanges) = span rowHasChanges rows

 -- | Whether a row has changes on either side.
-rowHasChanges :: (Prologue.Foldable f, Functor f) => Join These (SplitDiff f annotation) -> Bool
+rowHasChanges :: (Foldable f, Functor f) => Join These (SplitDiff f annotation) -> Bool
 rowHasChanges row = or (hasChanges <$> row)
--- a/src/Renderer/Split.hs
+++ b/src/Renderer/Split.hs
@ -10,7 +10,7 @@ import Data.Record
 import qualified Data.Text.Lazy as TL
 import Data.These
 import Info
-import Prologue hiding (div, head, fst, snd, link)
+import Prologue hiding (div, head, fst, snd, link, (<>))
 import qualified Prologue
 import Renderer
 import Source
@ -33,7 +33,8 @@ styleName :: Category -> Text
 styleName category = "category-" <> case category of
  Program -> "program"
  C.Error -> "error"
-  BinaryOperator -> "binary_operator"
+  BooleanOperator -> "boolean_operator"
+  MathOperator -> "math_operator"
  BitwiseOperator -> "bitwise_operator"
  RelationalOperator -> "relational_operator"
  Boolean -> "boolean"
@ -114,9 +115,9 @@ split blobs diff = SplitOutput . TL.toStrict . renderHtml
    numberedLinesToMarkup numberedLines = tr $ runBothWith (<>) (renderLine <$> Join (fromThese Nothing Nothing (runJoin (Just <$> numberedLines))) <*> sources) <> string "\n"

    renderLine (Just (number, line)) source = toMarkup $ Cell (hasChanges line) number (Renderable source line)
-    renderLine _ _ =
-      td mempty ! A.class_ (stringValue "blob-num blob-num-empty empty-cell")
-      <> td mempty ! A.class_ (stringValue "blob-code blob-code-empty empty-cell")
+    renderLine _ _
+      =  (td mempty ! A.class_ (stringValue "blob-num blob-num-empty empty-cell"))
+      <> (td mempty ! A.class_ (stringValue "blob-code blob-code-empty empty-cell"))
      <> string "\n"

 -- | A cell in a table, characterized by whether it contains changes & its line number.
@ -142,12 +143,12 @@ wrapIn f p = f p

 -- Instances

-instance (ToMarkup f, HasField fields Category, HasField fields Cost, HasField fields Range) => ToMarkup (Renderable (SyntaxTermF leaf fields (f, Range))) where
+instance (ToMarkup f, HasField fields Category, HasField fields Range) => ToMarkup (Renderable (SyntaxTermF leaf fields (f, Range))) where
  toMarkup (Renderable source (info :< syntax)) = classifyMarkup (category info) $ case syntax of
    Leaf _ -> span . string . toString $ slice (characterRange info) source
    _ -> ul . mconcat $ wrapIn li <$> contentElements source (characterRange info) (toList syntax)

-instance (HasField fields Category, HasField fields Cost, HasField fields Range) => ToMarkup (Renderable (SyntaxTerm leaf fields)) where
+instance (HasField fields Category, HasField fields Range) => ToMarkup (Renderable (SyntaxTerm leaf fields)) where
  toMarkup (Renderable source term) = Prologue.fst $ cata (\ t -> (toMarkup $ Renderable source t, characterRange (headF t))) term

 instance (HasField fields Category, HasField fields Cost, HasField fields Range) => ToMarkup (Renderable (SplitSyntaxDiff leaf fields)) where
@ -159,7 +160,10 @@ instance (HasField fields Category, HasField fields Cost, HasField fields Range)
                                       | otherwise = identity

 instance ToMarkup a => ToMarkup (Cell a) where
-  toMarkup (Cell hasChanges num line) =
-    td (string $ show num) ! A.class_ (stringValue $ if hasChanges then "blob-num blob-num-replacement" else "blob-num")
-    <> td (toMarkup line) ! A.class_ (stringValue $ if hasChanges then "blob-code blob-code-replacement" else "blob-code")
+  toMarkup (Cell hasChanges num line)
+    =  (td (string (show num)) ! A.class_ (stringValue $ if hasChanges then "blob-num blob-num-replacement" else "blob-num"))
+    <> (td (toMarkup line) ! A.class_ (stringValue $ if hasChanges then "blob-code blob-code-replacement" else "blob-code"))
    <> string "\n"
+
+(<>) :: Monoid m => m -> m -> m
+(<>) = mappend
--- a/src/Source.hs
+++ b/src/Source.hs
@ -7,6 +7,7 @@ import Data.String
 import qualified Data.Vector as Vector
 import Numeric
 import Range
+import SourceSpan

 -- | The source, oid, path, and Maybe SourceKind of a blob in a Git repo.
 data SourceBlob = SourceBlob { source :: Source Char, oid :: String, path :: FilePath, blobKind :: Maybe SourceKind }
@ -77,24 +78,31 @@ uncons (Source vector) = if null vector then Nothing else Just (Vector.head vect
 break :: (a -> Bool) -> Source a -> (Source a, Source a)
 break predicate (Source vector) = let (start, remainder) = Vector.break predicate vector in (Source start, Source remainder)

-- | Concatenate two sources.
-(++) :: Source a -> Source a -> Source a
-(++) (Source a) = Source . (a Vector.++) . getVector
-
 -- | Split the contents of the source after newlines.
 actualLines :: Source Char -> [Source Char]
 actualLines source | null source = [ source ]
 actualLines source = case Source.break (== '\n') source of
  (l, lines') -> case uncons lines' of
    Nothing -> [ l ]
-    Just (_, lines') -> (l Source.++ fromList "\n") : actualLines lines'
+    Just (_, lines') -> (l <> fromList "\n") : actualLines lines'

 -- | Compute the line ranges within a given range of a string.
 actualLineRanges :: Range -> Source Char -> [Range]
 actualLineRanges range = drop 1 . scanl toRange (Range (start range) (start range)) . actualLines . slice range
  where toRange previous string = Range (end previous) $ end previous + length string

+-- | Compute the character range corresponding to a given SourceSpan within a Source.
+sourceSpanToRange :: Source Char -> SourceSpan -> Range
+sourceSpanToRange source SourceSpan{..} = Range start end
+  where start = sumLengths leadingRanges + column spanStart
+        end = start + sumLengths (take (line spanEnd - line spanStart) remainingRanges) + (column spanEnd - column spanStart)
+        (leadingRanges, remainingRanges) = splitAt (line spanStart) (actualLineRanges (totalRange source) source)
+        sumLengths = sum . fmap (\ Range{..} -> end - start)
+
+
+instance Semigroup (Source a) where
+  Source a <> Source b = Source (a Vector.++ b)

 instance Monoid (Source a) where
  mempty = fromList []
-  mappend = (Source.++)
+  mappend = (<>)
--- a/src/Term.hs
+++ b/src/Term.hs
@ -18,18 +18,18 @@ type SyntaxTermF leaf fields = TermF (Syntax leaf) (Record fields)
 type SyntaxTerm leaf fields = Term (Syntax leaf) (Record fields)

 type instance Base (Term f a) = TermF f a
-instance Functor f => Foldable.Foldable (Term f a) where project = runCofree
-instance Functor f => Foldable.Unfoldable (Term f a) where embed = cofree
+instance Functor f => Recursive (Term f a) where project = runCofree
+instance Functor f => Corecursive (Term f a) where embed = cofree

 -- | Zip two terms by combining their annotations into a pair of annotations.
 -- | If the structure of the two terms don't match, then Nothing will be returned.

-zipTerms :: (Eq annotation, Traversable f, GAlign f) => Term f annotation -> Term f annotation -> Maybe (Term f (Both annotation))
+zipTerms :: (Traversable f, GAlign f) => Term f annotation -> Term f annotation -> Maybe (Term f (Both annotation))
 zipTerms t1 t2 = iter go (alignCofreeWith galign (const Nothing) both (These t1 t2))
  where go (a :< s) = cofree . (a :<) <$> sequenceA s

 -- | Return the node count of a term.
-termSize :: (Prologue.Foldable f, Functor f) => Term f annotation -> Int
+termSize :: (Foldable f, Functor f) => Term f annotation -> Int
 termSize = cata size where
  size (_ :< syntax) = 1 + sum syntax

--- a/src/Term/Arbitrary.hs
+++ b/src/Term/Arbitrary.hs
@ -1,7 +1,7 @@
 {-# LANGUAGE TypeFamilies #-}
 module Term.Arbitrary where

-import Data.Functor.Foldable (Base, cata, unfold, Unfoldable(embed))
+import Data.Functor.Foldable (Base, cata, unfold, Corecursive(embed))
 import Data.Text.Arbitrary ()
 import Prologue
 import Syntax
@ -27,7 +27,7 @@ arbitraryTermSize = cata (succ . sum) . toTerm
 -- Instances

 type instance Base (ArbitraryTerm leaf annotation) = TermF (Syntax leaf) annotation
-instance Unfoldable (ArbitraryTerm leaf annotation) where embed (a :< s) = ArbitraryTerm a s
+instance Corecursive (ArbitraryTerm leaf annotation) where embed (a :< s) = ArbitraryTerm a s

 instance (Eq leaf, Eq annotation, Arbitrary leaf, Arbitrary annotation) => Arbitrary (ArbitraryTerm leaf annotation) where
  arbitrary = sized $ \ n -> do
--- a/src/TreeSitter.hs
+++ b/src/TreeSitter.hs
@ -2,7 +2,6 @@
 module TreeSitter (treeSitterParser) where

 import Prologue hiding (Constructor)
-import Control.Monad
 import Category
 import Data.Record
 import Language
--- a/test/AlignmentSpec.hs
+++ b/test/AlignmentSpec.hs
@ -10,7 +10,7 @@ import Data.Bifunctor.Join
 import Data.Bifunctor.Join.Arbitrary ()
 import Data.Functor.Both as Both
 import Data.List (nub)
-import Data.Monoid
+import Data.Monoid hiding ((<>))
 import Data.Record
 import Data.String
 import Data.Text.Arbitrary ()
@ -270,7 +270,7 @@ prettyDiff sources = PrettyDiff sources . fmap (fmap ((getRange &&& identity) .
 data PrettyDiff a = PrettyDiff { unPrettySources :: Both (Source.Source Char), unPrettyLines :: [Join These (Range, a)] }
  deriving Eq

-instance Show a => Show (PrettyDiff a) where
+instance Show (PrettyDiff a) where
  showsPrec _ (PrettyDiff sources lines) = (prettyPrinted ++) -- . (("\n" ++ show lines) ++)
    where prettyPrinted = showLine (maximum (0 : (maximum . fmap length <$> shownLines))) <$> shownLines >>= ('\n':)
          shownLines = catMaybes $ toBoth <$> lines
--- a/test/Data/RandomWalkSimilarity/Spec.hs
+++ b/test/Data/RandomWalkSimilarity/Spec.hs
@ -5,6 +5,7 @@ import Data.Functor.Both
 import Data.Functor.Foldable (cata)
 import Data.RandomWalkSimilarity
 import Data.Record
+import qualified Data.Vector as Vector
 import Diff
 import Info
 import Patch
@ -21,17 +22,16 @@ spec = parallel $ do
  let positively = succ . abs
  describe "pqGramDecorator" $ do
    prop "produces grams with stems of the specified length" $
-      \ (term, p, q) -> pqGramDecorator (rhead . headF) (positively p) (positively q) (toTerm term :: Term (Syntax Text) (Record '[Text])) `shouldSatisfy` all ((== (positively p)) . length . stem . rhead)
+      \ (term, p, q) -> pqGramDecorator (rhead . headF) (positively p) (positively q) (toTerm term :: Term (Syntax Text) (Record '[Text])) `shouldSatisfy` all ((== positively p) . length . stem . rhead)

    prop "produces grams with bases of the specified width" $
-      \ (term, p, q) -> pqGramDecorator (rhead . headF) (positively p) (positively q) (toTerm term :: Term (Syntax Text) (Record '[Text])) `shouldSatisfy` all ((== (positively q)) . length . base . rhead)
+      \ (term, p, q) -> pqGramDecorator (rhead . headF) (positively p) (positively q) (toTerm term :: Term (Syntax Text) (Record '[Text])) `shouldSatisfy` all ((== positively q) . length . base . rhead)

  describe "featureVectorDecorator" $ do
    prop "produces a vector of the specified dimension" $
-      \ (term, p, q, d) -> featureVectorDecorator (rhead . headF) (positively p) (positively q) (positively d) (toTerm term :: Term (Syntax Text) (Record '[Text])) `shouldSatisfy` all ((== (positively d)) . length . rhead)
+      \ (term, p, q, d) -> featureVectorDecorator (rhead . headF) (positively p) (positively q) (positively d) (toTerm term :: Term (Syntax Text) (Record '[Text])) `shouldSatisfy` all ((== positively d) . length . rhead)

  describe "rws" $ do
-    let decorate = defaultFeatureVectorDecorator (category . headF)
    let toTerm' = decorate . toTerm
    prop "produces correct diffs" . forAll (scale (`div` 4) arbitrary) $
      \ (as, bs) -> let tas = toTerm' <$> (as :: [ArbitraryTerm Text (Record '[Category])])
@ -41,7 +41,7 @@ spec = parallel $ do
        (beforeTerm diff, afterTerm diff) `shouldBe` (Just (root (stripTerm <$> tas)), Just (root (stripTerm <$> tbs)))

    it "produces unbiased insertions within branches" $
-      let (a, b) = (decorate (cofree ((StringLiteral .: RNil) :< Indexed [ cofree ((StringLiteral .: RNil) :< Leaf "a") ])), decorate (cofree ((StringLiteral .: RNil) :< Indexed [ cofree ((StringLiteral .: RNil) :< Leaf "b") ]))) in
+      let (a, b) = (decorate (cofree ((StringLiteral .: RNil) :< Indexed [ cofree ((StringLiteral .: RNil) :< Leaf ("a" :: Text)) ])), decorate (cofree ((StringLiteral .: RNil) :< Indexed [ cofree ((StringLiteral .: RNil) :< Leaf "b") ]))) in
      fmap stripDiff (rws compare [ b ] [ a, b ]) `shouldBe` fmap stripDiff [ inserting a, copying b ]

  where compare :: (HasField fields Category, Functor f, Eq (Cofree f Category)) => Cofree f (Record fields) -> Cofree f (Record fields) -> Maybe (Free (CofreeF f (Both (Record fields))) (Patch (Cofree f (Record fields))))
@ -49,3 +49,5 @@ spec = parallel $ do
                    | otherwise = if ((==) `on` category . extract) a b then Just (replacing a b) else Nothing
        copying :: Functor f => Cofree f (Record fields) -> Free (CofreeF f (Both (Record fields))) (Patch (Cofree f (Record fields)))
        copying = cata wrap . fmap pure
+        decorate :: SyntaxTerm leaf '[Category] -> SyntaxTerm leaf '[Vector.Vector Double, Category]
+        decorate = defaultFeatureVectorDecorator (category . headF)
--- a/test/RangeSpec.hs
+++ b/test/RangeSpec.hs
@ -1,9 +1,9 @@
 module RangeSpec where

 import Prologue
+import Range
 import Test.Hspec (Spec, describe, it, parallel)
 import Test.Hspec.Expectations.Pretty
-import Range

 spec :: Spec
 spec = parallel $ do
--- a/test/Source/Spec.hs
+++ b/test/Source/Spec.hs
@ -0,0 +1,53 @@
+module Source.Spec where
+
+import qualified Prelude
+import Prologue
+import Range
+import Source
+import SourceSpan
+import Test.Hspec
+import Test.Hspec.QuickCheck
+
+spec :: Spec
+spec = parallel $ do
+  describe "actualLineRanges" $ do
+    prop "produces 1 more range than there are newlines" $
+      \ s -> length (actualLineRanges (totalRange s) (fromList s)) `shouldBe` succ (length (filter (== '\n') s))
+
+    prop "produces exhaustive ranges" $
+      \ s -> let source = fromList s in
+        foldMap (`slice` source) (actualLineRanges (totalRange s) source) `shouldBe` source
+
+  describe "sourceSpanToRange" $ do
+    prop "computes single-line ranges" $
+      \ s -> let source = fromList s
+                 spans = zipWith (\ i Range {..} -> SourceSpan "" (SourcePos i 0) (SourcePos i (end - start))) [0..] ranges
+                 ranges = actualLineRanges (totalRange source) source in
+        sourceSpanToRange source <$> spans `shouldBe` ranges
+
+    prop "computes multi-line ranges" $
+      \ s -> let source = fromList s in
+        sourceSpanToRange source (totalSpan source) `shouldBe` totalRange source
+
+    prop "computes sub-line ranges" $
+      \ s -> let source = fromList ('*' : s <> "*") in
+        sourceSpanToRange source (insetSpan (totalSpan source)) `shouldBe` insetRange (totalRange source)
+
+  describe "totalSpan" $ do
+    prop "covers single lines" $
+      \ n -> totalSpan (fromList (replicate n '*')) `shouldBe` SourceSpan "" (SourcePos 0 0) (SourcePos 0 (max 0 n))
+
+    prop "covers multiple lines" $
+      \ n -> totalSpan (fromList (intersperse '\n' (replicate n '*'))) `shouldBe` SourceSpan "" (SourcePos 0 0) (SourcePos (max 0 (pred n)) (if n > 0 then 1 else 0))
+
+totalSpan :: Source Char -> SourceSpan
+totalSpan source = SourceSpan "" (SourcePos 0 0) (SourcePos (pred (length ranges)) (end lastRange - start lastRange))
+  where ranges = actualLineRanges (totalRange source) source
+        lastRange = Prelude.last ranges
+
+insetSpan :: SourceSpan -> SourceSpan
+insetSpan sourceSpan = sourceSpan { spanStart = (spanStart sourceSpan) { column = succ (column (spanStart sourceSpan)) }
+                                  , spanEnd = (spanEnd sourceSpan) { column = pred (column (spanEnd sourceSpan)) } }
+
+insetRange :: Range -> Range
+insetRange Range {..} = Range (succ start) (pred end)
--- a/test/Spec.hs
+++ b/test/Spec.hs
@ -10,6 +10,7 @@ import qualified DiffSummarySpec
 import qualified InterpreterSpec
 import qualified PatchOutputSpec
 import qualified RangeSpec
+import qualified Source.Spec
 import qualified TermSpec
 import Test.Hspec

@ -23,5 +24,6 @@ main = hspec . parallel $ do
  describe "DiffSummary" DiffSummarySpec.spec
  describe "Interpreter" InterpreterSpec.spec
  describe "PatchOutput" PatchOutputSpec.spec
-  describe "RangeSpec" RangeSpec.spec
+  describe "Range" RangeSpec.spec
+  describe "Source" Source.Spec.spec
  describe "Term" TermSpec.spec
--- a/vendor/gitlib
+++ b/vendor/gitlib
@ -1 +1 @@
-Subproject commit 4828dbf14adfc4ce0ac3536f8b192e65828e97bc
+Subproject commit 77df9cce6bbc37f36f4554a31b36336ba887fcd2