%
-% (c) The University of Glasgow, 1992-2003
+% (c) The University of Glasgow, 1992-2006
%
-%************************************************************************
-%* *
-\section[SrcLoc]{The @SrcLoc@ type}
-%* *
-%************************************************************************
\begin{code}
+-- | This module contains types that relate to the positions of things
+-- in source files, and allow tagging of those things with locations
module SrcLoc (
+ -- * SrcLoc
SrcLoc, -- Abstract
- mkSrcLoc, isGoodSrcLoc, mkGeneralSrcLoc,
- noSrcLoc, -- "I'm sorry, I haven't a clue"
- advanceSrcLoc,
+ -- ** Constructing SrcLoc
+ mkSrcLoc, mkGeneralSrcLoc,
- importedSrcLoc, -- Unknown place in an interface
- wiredInSrcLoc, -- Something wired into the compiler
+ noSrcLoc, -- "I'm sorry, I haven't a clue"
generatedSrcLoc, -- Code generated within the compiler
interactiveSrcLoc, -- Code from an interactive session
+ advanceSrcLoc,
+
+ -- ** Unsafely deconstructing SrcLoc
+ -- These are dubious exports, because they crash on some inputs
srcLocFile, -- return the file name part
srcLocLine, -- return the line part
srcLocCol, -- return the column part
+
+ -- ** Misc. operations on SrcLoc
pprDefnLoc,
+
+ -- ** Predicates on SrcLoc
+ isGoodSrcLoc,
+ -- * SrcSpan
SrcSpan, -- Abstract
- noSrcSpan,
- mkGeneralSrcSpan,
- isGoodSrcSpan,
- mkSrcSpan, srcLocSpan,
+
+ -- ** Constructing SrcSpan
+ mkGeneralSrcSpan, mkSrcSpan,
+ noSrcSpan,
+ wiredInSrcSpan, -- Something wired into the compiler
+ srcLocSpan,
combineSrcSpans,
- srcSpanFile,
- srcSpanStartLine, srcSpanEndLine,
- srcSpanStartCol, srcSpanEndCol,
+
+ -- ** Deconstructing SrcSpan
srcSpanStart, srcSpanEnd,
-
- Located(..), getLoc, unLoc, noLoc, eqLocated, cmpLocated, combineLocs, addCLoc
+ srcSpanFileName_maybe,
+
+ -- ** Unsafely deconstructing SrcSpan
+ -- These are dubious exports, because they crash on some inputs
+ srcSpanFile,
+ srcSpanStartLine, srcSpanEndLine,
+ srcSpanStartCol, srcSpanEndCol,
+
+ -- ** Predicates on SrcSpan
+ isGoodSrcSpan, isOneLineSpan,
+
+ -- * Located
+ Located(..),
+
+ -- ** Constructing Located
+ noLoc,
+ mkGeneralLocated,
+
+ -- ** Deconstructing Located
+ getLoc, unLoc,
+
+ -- ** Combining and comparing Located values
+ eqLocated, cmpLocated, combineLocs, addCLoc,
+ leftmost_smallest, leftmost_largest, rightmost,
+ spans, isSubspanOf
) where
-#include "HsVersions.h"
-
-import Util ( thenCmp )
+import Util
import Outputable
import FastString
\end{code}
We keep information about the {\em definition} point for each entity;
this is the obvious stuff:
\begin{code}
+-- | Represents a single point within a file
data SrcLoc
= SrcLoc FastString -- A precise location (file name)
- !Int -- line number, begins at 1
- !Int -- column number, begins at 0
- -- Don't ask me why lines start at 1 and columns start at
- -- zero. That's just the way it is, so there. --SDM
-
- | ImportedLoc String -- Module name
-
+ {-# UNPACK #-} !Int -- line number, begins at 1
+ {-# UNPACK #-} !Int -- column number, begins at 1
| UnhelpfulLoc FastString -- Just a general indication
\end{code}
-Note that an entity might be imported via more than one route, and
-there could be more than one ``definition point'' --- in two or more
-\tr{.hi} files. We deemed it probably-unworthwhile to cater for this
-rare case.
-
%************************************************************************
%* *
-\subsection[SrcLoc-access-fns]{Access functions for names}
+\subsection[SrcLoc-access-fns]{Access functions}
%* *
%************************************************************************
-Things to make 'em:
\begin{code}
+mkSrcLoc :: FastString -> Int -> Int -> SrcLoc
mkSrcLoc x line col = SrcLoc x line col
-noSrcLoc = UnhelpfulLoc FSLIT("<no location info>")
-generatedSrcLoc = UnhelpfulLoc FSLIT("<compiler-generated code>")
-wiredInSrcLoc = UnhelpfulLoc FSLIT("<wired into compiler>")
-interactiveSrcLoc = UnhelpfulLoc FSLIT("<interactive session>")
+-- | Built-in "bad" 'SrcLoc' values for particular locations
+noSrcLoc, generatedSrcLoc, interactiveSrcLoc :: SrcLoc
+noSrcLoc = UnhelpfulLoc (fsLit "<no location info>")
+generatedSrcLoc = UnhelpfulLoc (fsLit "<compiler-generated code>")
+interactiveSrcLoc = UnhelpfulLoc (fsLit "<interactive session>")
+
+-- | Creates a "bad" 'SrcLoc' that has no detailed information about its location
mkGeneralSrcLoc :: FastString -> SrcLoc
mkGeneralSrcLoc = UnhelpfulLoc
-importedSrcLoc :: String -> SrcLoc
-importedSrcLoc mod_name = ImportedLoc mod_name
-
+-- | "Good" 'SrcLoc's have precise information about their location
+isGoodSrcLoc :: SrcLoc -> Bool
isGoodSrcLoc (SrcLoc _ _ _) = True
-isGoodSrcLoc other = False
+isGoodSrcLoc _other = False
+-- | Gives the filename of the 'SrcLoc' if it is available, otherwise returns a dummy value
srcLocFile :: SrcLoc -> FastString
srcLocFile (SrcLoc fname _ _) = fname
-srcLocFile other = FSLIT("<unknown file")
+srcLocFile _other = (fsLit "<unknown file")
+-- | Raises an error when used on a "bad" 'SrcLoc'
srcLocLine :: SrcLoc -> Int
-srcLocLine (SrcLoc _ l c) = l
-srcLocLine other = panic "srcLocLine: unknown line"
+srcLocLine (SrcLoc _ l _) = l
+srcLocLine _other = panic "srcLocLine: unknown line"
+-- | Raises an error when used on a "bad" 'SrcLoc'
srcLocCol :: SrcLoc -> Int
-srcLocCol (SrcLoc _ l c) = c
-srcLocCol other = panic "srcLocCol: unknown col"
+srcLocCol (SrcLoc _ _ c) = c
+srcLocCol _other = panic "srcLocCol: unknown col"
+-- | Move the 'SrcLoc' down by one line if the character is a newline
+-- and across by one character in any other case
advanceSrcLoc :: SrcLoc -> Char -> SrcLoc
-advanceSrcLoc (SrcLoc f l c) '\n' = SrcLoc f (l + 1) 0
+advanceSrcLoc (SrcLoc f l _) '\n' = SrcLoc f (l + 1) 1
advanceSrcLoc (SrcLoc f l c) _ = SrcLoc f l (c + 1)
advanceSrcLoc loc _ = loc -- Better than nothing
\end{code}
-- SrcLoc is an instance of Ord so that we can sort error messages easily
instance Eq SrcLoc where
loc1 == loc2 = case loc1 `cmpSrcLoc` loc2 of
- EQ -> True
- other -> False
+ EQ -> True
+ _other -> False
instance Ord SrcLoc where
compare = cmpSrcLoc
-
+
+cmpSrcLoc :: SrcLoc -> SrcLoc -> Ordering
cmpSrcLoc (UnhelpfulLoc s1) (UnhelpfulLoc s2) = s1 `compare` s2
-cmpSrcLoc (UnhelpfulLoc _) other = LT
-
-cmpSrcLoc (ImportedLoc _) (UnhelpfulLoc _) = GT
-cmpSrcLoc (ImportedLoc m1) (ImportedLoc m2) = m1 `compare` m2
-cmpSrcLoc (ImportedLoc _) other = LT
+cmpSrcLoc (UnhelpfulLoc _) _other = LT
cmpSrcLoc (SrcLoc s1 l1 c1) (SrcLoc s2 l2 c2)
- = (s1 `compare` s2) `thenCmp` (l1 `cmpline` l2) `thenCmp` (c1 `cmpline` c2)
- where
- l1 `cmpline` l2 | l1 < l2 = LT
- | l1 == l2 = EQ
- | otherwise = GT
-cmpSrcLoc (SrcLoc _ _ _) other = GT
+ = (s1 `compare` s2) `thenCmp` (l1 `compare` l2) `thenCmp` (c1 `compare` c2)
+cmpSrcLoc (SrcLoc _ _ _) _other = GT
instance Outputable SrcLoc where
ppr (SrcLoc src_path src_line src_col)
= getPprStyle $ \ sty ->
if userStyle sty || debugStyle sty then
- hcat [ ftext src_path, char ':',
- int src_line,
- char ':', int src_col
- ]
- else
- hcat [text "{-# LINE ", int src_line, space,
- char '\"', ftext src_path, text " #-}"]
-
- ppr (ImportedLoc mod) = ptext SLIT("Imported from") <+> text mod
+ hcat [ pprFastFilePath src_path, char ':',
+ int src_line,
+ char ':', int src_col
+ ]
+ else
+ hcat [text "{-# LINE ", int src_line, space,
+ char '\"', pprFastFilePath src_path, text " #-}"]
+
ppr (UnhelpfulLoc s) = ftext s
\end{code}
slightly by using more compact representations for single-line and
zero-length spans, both of which are quite common.
-The end position is defined to be the column *after* the end of the
+The end position is defined to be the column /after/ the end of the
span. That is, a span of (1,1)-(1,2) is one character long, and a
span of (1,1)-(1,1) is zero characters long.
-}
data SrcSpan
= SrcSpanOneLine -- a common case: a single line
- { srcSpanFile :: FastString,
- srcSpanLine :: !Int,
- srcSpanSCol :: !Int,
- srcSpanECol :: !Int
+ { srcSpanFile :: !FastString,
+ srcSpanLine :: {-# UNPACK #-} !Int,
+ srcSpanSCol :: {-# UNPACK #-} !Int,
+ srcSpanECol :: {-# UNPACK #-} !Int
}
| SrcSpanMultiLine
- { srcSpanFile :: FastString,
- srcSpanSLine :: !Int,
- srcSpanSCol :: !Int,
- srcSpanELine :: !Int,
- srcSpanECol :: !Int
+ { srcSpanFile :: !FastString,
+ srcSpanSLine :: {-# UNPACK #-} !Int,
+ srcSpanSCol :: {-# UNPACK #-} !Int,
+ srcSpanELine :: {-# UNPACK #-} !Int,
+ srcSpanECol :: {-# UNPACK #-} !Int
}
| SrcSpanPoint
- { srcSpanFile :: FastString,
- srcSpanLine :: !Int,
- srcSpanCol :: !Int
+ { srcSpanFile :: !FastString,
+ srcSpanLine :: {-# UNPACK #-} !Int,
+ srcSpanCol :: {-# UNPACK #-} !Int
}
- | ImportedSpan String -- Module name
-
- | UnhelpfulSpan FastString -- Just a general indication
+ | UnhelpfulSpan !FastString -- Just a general indication
-- also used to indicate an empty span
+#ifdef DEBUG
+ deriving (Eq, Show) -- Show is used by Lexer.x, becuase we
+ -- derive Show for Token
+#else
deriving Eq
+#endif
--- We want to order SrcSpans first by the start point, then by the end point.
-instance Ord SrcSpan where
- a `compare` b =
- (srcSpanStart a `compare` srcSpanStart b) `thenCmp`
- (srcSpanEnd a `compare` srcSpanEnd b)
-
-noSrcSpan = UnhelpfulSpan FSLIT("<no location info>")
+-- | Built-in "bad" 'SrcSpan's for common sources of location uncertainty
+noSrcSpan, wiredInSrcSpan :: SrcSpan
+noSrcSpan = UnhelpfulSpan (fsLit "<no location info>")
+wiredInSrcSpan = UnhelpfulSpan (fsLit "<wired into compiler>")
+-- | Create a "bad" 'SrcSpan' that has not location information
mkGeneralSrcSpan :: FastString -> SrcSpan
mkGeneralSrcSpan = UnhelpfulSpan
+-- | Create a 'SrcSpan' corresponding to a single point
+srcLocSpan :: SrcLoc -> SrcSpan
+srcLocSpan (UnhelpfulLoc str) = UnhelpfulSpan str
+srcLocSpan (SrcLoc file line col) = SrcSpanPoint file line col
+
+-- | Create a 'SrcSpan' between two points in a file
+mkSrcSpan :: SrcLoc -> SrcLoc -> SrcSpan
+mkSrcSpan (UnhelpfulLoc str) _ = UnhelpfulSpan str
+mkSrcSpan _ (UnhelpfulLoc str) = UnhelpfulSpan str
+mkSrcSpan loc1 loc2
+ | line1 == line2 = if col1 == col2
+ then SrcSpanPoint file line1 col1
+ else SrcSpanOneLine file line1 col1 col2
+ | otherwise = SrcSpanMultiLine file line1 col1 line2 col2
+ where
+ line1 = srcLocLine loc1
+ line2 = srcLocLine loc2
+ col1 = srcLocCol loc1
+ col2 = srcLocCol loc2
+ file = srcLocFile loc1
+
+-- | Combines two 'SrcSpan' into one that spans at least all the characters
+-- within both spans. Assumes the "file" part is the same in both inputs
+combineSrcSpans :: SrcSpan -> SrcSpan -> SrcSpan
+combineSrcSpans (UnhelpfulSpan _) r = r -- this seems more useful
+combineSrcSpans l (UnhelpfulSpan _) = l
+combineSrcSpans start end
+ = case line1 `compare` line2 of
+ EQ -> case col1 `compare` col2 of
+ EQ -> SrcSpanPoint file line1 col1
+ LT -> SrcSpanOneLine file line1 col1 col2
+ GT -> SrcSpanOneLine file line1 col2 col1
+ LT -> SrcSpanMultiLine file line1 col1 line2 col2
+ GT -> SrcSpanMultiLine file line2 col2 line1 col1
+ where
+ line1 = srcSpanStartLine start
+ col1 = srcSpanStartCol start
+ line2 = srcSpanEndLine end
+ col2 = srcSpanEndCol end
+ file = srcSpanFile start
+\end{code}
+
+%************************************************************************
+%* *
+\subsection[SrcSpan-predicates]{Predicates}
+%* *
+%************************************************************************
+
+\begin{code}
+-- | Test if a 'SrcSpan' is "good", i.e. has precise location information
+isGoodSrcSpan :: SrcSpan -> Bool
isGoodSrcSpan SrcSpanOneLine{} = True
isGoodSrcSpan SrcSpanMultiLine{} = True
isGoodSrcSpan SrcSpanPoint{} = True
isGoodSrcSpan _ = False
+isOneLineSpan :: SrcSpan -> Bool
+-- ^ True if the span is known to straddle only one line.
+-- For "bad" 'SrcSpan', it returns False
+isOneLineSpan s
+ | isGoodSrcSpan s = srcSpanStartLine s == srcSpanEndLine s
+ | otherwise = False
+
+\end{code}
+
+%************************************************************************
+%* *
+\subsection[SrcSpan-unsafe-access-fns]{Unsafe access functions}
+%* *
+%************************************************************************
+
+\begin{code}
+
+-- | Raises an error when used on a "bad" 'SrcSpan'
+srcSpanStartLine :: SrcSpan -> Int
+-- | Raises an error when used on a "bad" 'SrcSpan'
+srcSpanEndLine :: SrcSpan -> Int
+-- | Raises an error when used on a "bad" 'SrcSpan'
+srcSpanStartCol :: SrcSpan -> Int
+-- | Raises an error when used on a "bad" 'SrcSpan'
+srcSpanEndCol :: SrcSpan -> Int
+
srcSpanStartLine SrcSpanOneLine{ srcSpanLine=l } = l
srcSpanStartLine SrcSpanMultiLine{ srcSpanSLine=l } = l
srcSpanStartLine SrcSpanPoint{ srcSpanLine=l } = l
srcSpanEndCol SrcSpanPoint{ srcSpanCol=c } = c
srcSpanEndCol _ = panic "SrcLoc.srcSpanEndCol"
-srcSpanStart (ImportedSpan str) = ImportedLoc str
+\end{code}
+
+%************************************************************************
+%* *
+\subsection[SrcSpan-access-fns]{Access functions}
+%* *
+%************************************************************************
+
+\begin{code}
+
+-- | Returns the location at the start of the 'SrcSpan' or a "bad" 'SrcSpan' if that is unavailable
+srcSpanStart :: SrcSpan -> SrcLoc
+-- | Returns the location at the end of the 'SrcSpan' or a "bad" 'SrcSpan' if that is unavailable
+srcSpanEnd :: SrcSpan -> SrcLoc
+
srcSpanStart (UnhelpfulSpan str) = UnhelpfulLoc str
-srcSpanStart s =
- mkSrcLoc (srcSpanFile s)
- (srcSpanStartLine s)
- (srcSpanStartCol s)
+srcSpanStart s = mkSrcLoc (srcSpanFile s)
+ (srcSpanStartLine s)
+ (srcSpanStartCol s)
-srcSpanEnd (ImportedSpan str) = ImportedLoc str
srcSpanEnd (UnhelpfulSpan str) = UnhelpfulLoc str
srcSpanEnd s =
mkSrcLoc (srcSpanFile s)
(srcSpanEndLine s)
(srcSpanEndCol s)
-srcLocSpan :: SrcLoc -> SrcSpan
-srcLocSpan (ImportedLoc str) = ImportedSpan str
-srcLocSpan (UnhelpfulLoc str) = UnhelpfulSpan str
-srcLocSpan (SrcLoc file line col) = SrcSpanPoint file line col
+-- | Obtains the filename for a 'SrcSpan' if it is "good"
+srcSpanFileName_maybe :: SrcSpan -> Maybe FastString
+srcSpanFileName_maybe (SrcSpanOneLine { srcSpanFile = nm }) = Just nm
+srcSpanFileName_maybe (SrcSpanMultiLine { srcSpanFile = nm }) = Just nm
+srcSpanFileName_maybe (SrcSpanPoint { srcSpanFile = nm}) = Just nm
+srcSpanFileName_maybe _ = Nothing
-mkSrcSpan :: SrcLoc -> SrcLoc -> SrcSpan
-mkSrcSpan (ImportedLoc str) _ = ImportedSpan str
-mkSrcSpan (UnhelpfulLoc str) _ = UnhelpfulSpan str
-mkSrcSpan _ (ImportedLoc str) = ImportedSpan str
-mkSrcSpan _ (UnhelpfulLoc str) = UnhelpfulSpan str
-mkSrcSpan loc1 loc2
- | line1 == line2 = if col1 == col2
- then SrcSpanPoint file line1 col1
- else SrcSpanOneLine file line1 col1 col2
- | otherwise = SrcSpanMultiLine file line1 col1 line2 col2
- where
- line1 = srcLocLine loc1
- line2 = srcLocLine loc2
- col1 = srcLocCol loc1
- col2 = srcLocCol loc2
- file = srcLocFile loc1
+\end{code}
-combineSrcSpans :: SrcSpan -> SrcSpan -> SrcSpan
--- Assumes the 'file' part is the same in both
-combineSrcSpans (ImportedSpan str) _ = ImportedSpan str
-combineSrcSpans (UnhelpfulSpan str) r = r -- this seems more useful
-combineSrcSpans _ (ImportedSpan str) = ImportedSpan str
-combineSrcSpans l (UnhelpfulSpan str) = l
-combineSrcSpans start end
- = case line1 `compare` line2 of
- EQ -> case col1 `compare` col2 of
- EQ -> SrcSpanPoint file line1 col1
- LT -> SrcSpanOneLine file line1 col1 col2
- GT -> SrcSpanOneLine file line1 col2 col1
- LT -> SrcSpanMultiLine file line1 col1 line2 col2
- GT -> SrcSpanMultiLine file line2 col2 line1 col1
- where
- line1 = srcSpanStartLine start
- col1 = srcSpanStartCol start
- line2 = srcSpanEndLine end
- col2 = srcSpanEndCol end
- file = srcSpanFile start
+%************************************************************************
+%* *
+\subsection[SrcSpan-instances]{Instances}
+%* *
+%************************************************************************
+
+\begin{code}
+
+-- We want to order SrcSpans first by the start point, then by the end point.
+instance Ord SrcSpan where
+ a `compare` b =
+ (srcSpanStart a `compare` srcSpanStart b) `thenCmp`
+ (srcSpanEnd a `compare` srcSpanEnd b)
-pprDefnLoc :: SrcLoc -> SDoc
--- "defined at ..." or "imported from ..."
-pprDefnLoc loc
- | isGoodSrcLoc loc = ptext SLIT("Defined at") <+> ppr loc
- | otherwise = ppr loc
instance Outputable SrcSpan where
ppr span
= getPprStyle $ \ sty ->
if userStyle sty || debugStyle sty then
- pprUserSpan span
- else
- hcat [text "{-# LINE ", int (srcSpanStartLine span), space,
- char '\"', ftext (srcSpanFile span), text " #-}"]
+ pprUserSpan True span
+ else
+ hcat [text "{-# LINE ", int (srcSpanStartLine span), space,
+ char '\"', pprFastFilePath $ srcSpanFile span, text " #-}"]
+
+pprUserSpan :: Bool -> SrcSpan -> SDoc
+pprUserSpan show_path (SrcSpanOneLine src_path line start_col end_col)
+ = hcat [ ppWhen show_path (pprFastFilePath src_path <> colon)
+ , int line, char ':', int start_col
+ , ppUnless (end_col - start_col <= 1)
+ (char '-' <> int (end_col-1))
+ -- For single-character or point spans, we just
+ -- output the starting column number
+ ]
+
+
+pprUserSpan show_path (SrcSpanMultiLine src_path sline scol eline ecol)
+ = hcat [ ppWhen show_path (pprFastFilePath src_path <> colon)
+ , parens (int sline <> char ',' <> int scol)
+ , char '-'
+ , parens (int eline <> char ',' <>
+ if ecol == 0 then int ecol else int (ecol-1))
+ ]
+pprUserSpan show_path (SrcSpanPoint src_path line col)
+ = hcat [ ppWhen show_path $ (pprFastFilePath src_path <> colon)
+ , int line, char ':', int col ]
-pprUserSpan (SrcSpanOneLine src_path line start_col end_col)
- = hcat [ ftext src_path, char ':',
- int line,
- char ':', int start_col
- ]
- <> if end_col - start_col <= 1
- then empty
- -- for single-character or point spans, we just output the starting
- -- column number
- else char '-' <> int (end_col-1)
-
-pprUserSpan (SrcSpanMultiLine src_path sline scol eline ecol)
- = hcat [ ftext src_path, char ':',
- parens (int sline <> char ',' <> int scol),
- char '-',
- parens (int eline <> char ',' <>
- if ecol == 0 then int ecol else int (ecol-1))
- ]
-
-pprUserSpan (SrcSpanPoint src_path line col)
- = hcat [ ftext src_path, char ':',
- int line,
- char ':', int col
- ]
+pprUserSpan _ (UnhelpfulSpan s) = ftext s
-pprUserSpan (ImportedSpan mod) = ptext SLIT("Imported from") <+> quotes (text mod)
-pprUserSpan (UnhelpfulSpan s) = ftext s
+pprDefnLoc :: SrcSpan -> SDoc
+-- ^ Pretty prints information about the 'SrcSpan' in the style "defined at ..."
+pprDefnLoc loc
+ | isGoodSrcSpan loc = ptext (sLit "Defined at") <+> ppr loc
+ | otherwise = ppr loc
\end{code}
%************************************************************************
noLoc :: e -> Located e
noLoc e = L noSrcSpan e
+mkGeneralLocated :: String -> e -> Located e
+mkGeneralLocated s e = L (mkGeneralSrcSpan (fsLit s)) e
+
combineLocs :: Located a -> Located b -> SrcSpan
combineLocs a b = combineSrcSpans (getLoc a) (getLoc b)
+-- | Combine locations from two 'Located' things and add them to a third thing
addCLoc :: Located a -> Located b -> c -> Located c
addCLoc a b c = L (combineSrcSpans (getLoc a) (getLoc b)) c
-- not clear whether to add a general Eq instance, but this is useful sometimes:
+
+-- | Tests whether the two located things are equal
eqLocated :: Eq a => Located a -> Located a -> Bool
eqLocated a b = unLoc a == unLoc b
--- not clear whether to add a general Eq instance, but this is useful sometimes:
+-- not clear whether to add a general Ord instance, but this is useful sometimes:
+
+-- | Tests the ordering of the two located things
cmpLocated :: Ord a => Located a -> Located a -> Ordering
cmpLocated a b = unLoc a `compare` unLoc b
fmap f (L l e) = L l (f e)
instance Outputable e => Outputable (Located e) where
- ppr (L span e) = ppr e
- -- do we want to dump the span in debugSty mode?
+ ppr (L l e) = ifPprDebug (braces (pprUserSpan False l)) <> ppr e
+ -- Print spans without the file name etc
+\end{code}
+
+%************************************************************************
+%* *
+\subsection{Ordering SrcSpans for InteractiveUI}
+%* *
+%************************************************************************
+
+\begin{code}
+-- | Alternative strategies for ordering 'SrcSpan's
+leftmost_smallest, leftmost_largest, rightmost :: SrcSpan -> SrcSpan -> Ordering
+rightmost = flip compare
+leftmost_smallest = compare
+leftmost_largest a b = (srcSpanStart a `compare` srcSpanStart b)
+ `thenCmp`
+ (srcSpanEnd b `compare` srcSpanEnd a)
+
+
+-- | Determines whether a span encloses a given line and column index
+spans :: SrcSpan -> (Int, Int) -> Bool
+spans span (l,c) = srcSpanStart span <= loc && loc <= srcSpanEnd span
+ where loc = mkSrcLoc (srcSpanFile span) l c
+
+-- | Determines whether a span is enclosed by another one
+isSubspanOf :: SrcSpan -- ^ The span that may be enclosed by the other
+ -> SrcSpan -- ^ The span it may be enclosed by
+ -> Bool
+isSubspanOf src parent
+ | srcSpanFileName_maybe parent /= srcSpanFileName_maybe src = False
+ | otherwise = srcSpanStart parent <= srcSpanStart src &&
+ srcSpanEnd parent >= srcSpanEnd src
+
\end{code}
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