ghc-7.0.4: The GHC API

SrcLoc

Contents

- SrcLoc
  - Constructing SrcLoc
  - Unsafely deconstructing SrcLoc
  - Misc. operations on SrcLoc
  - Predicates on SrcLoc
- SrcSpan
  - Constructing SrcSpan
  - Deconstructing SrcSpan
  - Unsafely deconstructing SrcSpan
  - Predicates on SrcSpan
- Located
  - Constructing Located
  - Deconstructing Located
  - Combining and comparing Located values

Description

This module contains types that relate to the positions of things in source files, and allow tagging of those things with locations

Synopsis

- data SrcLoc
- mkSrcLoc :: FastString -> Int -> Int -> SrcLoc
- mkGeneralSrcLoc :: FastString -> SrcLoc
- noSrcLoc :: SrcLoc
- generatedSrcLoc :: SrcLoc
- interactiveSrcLoc :: SrcLoc
- advanceSrcLoc :: SrcLoc -> Char -> SrcLoc
- srcLocFile :: SrcLoc -> FastString
- srcLocLine :: SrcLoc -> Int
- srcLocCol :: SrcLoc -> Int
- pprDefnLoc :: SrcSpan -> SDoc
- isGoodSrcLoc :: SrcLoc -> Bool
- data SrcSpan
- mkGeneralSrcSpan :: FastString -> SrcSpan
- mkSrcSpan :: SrcLoc -> SrcLoc -> SrcSpan
- noSrcSpan :: SrcSpan
- wiredInSrcSpan :: SrcSpan
- srcLocSpan :: SrcLoc -> SrcSpan
- combineSrcSpans :: SrcSpan -> SrcSpan -> SrcSpan
- srcSpanStart :: SrcSpan -> SrcLoc
- srcSpanEnd :: SrcSpan -> SrcLoc
- srcSpanFileName_maybe :: SrcSpan -> Maybe FastString
- srcSpanFile :: SrcSpan -> FastString
- srcSpanStartLine :: SrcSpan -> Int
- srcSpanEndLine :: SrcSpan -> Int
- srcSpanStartCol :: SrcSpan -> Int
- srcSpanEndCol :: SrcSpan -> Int
- isGoodSrcSpan :: SrcSpan -> Bool
- isOneLineSpan :: SrcSpan -> Bool
- data Located e = L SrcSpan e
- noLoc :: e -> Located e
- mkGeneralLocated :: String -> e -> Located e
- getLoc :: Located e -> SrcSpan
- unLoc :: Located e -> e
- eqLocated :: Eq a => Located a -> Located a -> Bool
- cmpLocated :: Ord a => Located a -> Located a -> Ordering
- combineLocs :: Located a -> Located b -> SrcSpan
- addCLoc :: Located a -> Located b -> c -> Located c
- leftmost_smallest :: SrcSpan -> SrcSpan -> Ordering
- leftmost_largest :: SrcSpan -> SrcSpan -> Ordering
- rightmost :: SrcSpan -> SrcSpan -> Ordering
- spans :: SrcSpan -> (Int, Int) -> Bool
- isSubspanOf :: SrcSpan -> SrcSpan -> Bool

# SrcLoc

data SrcLoc

Represents a single point within a file

Instances

Eq SrcLoc |
Ord SrcLoc |
Outputable SrcLoc |

## Constructing SrcLoc

mkSrcLoc :: FastString -> Int -> Int -> SrcLoc

mkGeneralSrcLoc :: FastString -> SrcLoc

Creates a bad `SrcLoc` that has no detailed information about its location

noSrcLoc :: SrcLoc

generatedSrcLoc :: SrcLoc

Built-in bad `SrcLoc` values for particular locations

interactiveSrcLoc :: SrcLoc

advanceSrcLoc :: SrcLoc -> Char -> SrcLoc

Move the `SrcLoc` down by one line if the character is a newline, to the next 8-char tabstop if it is a tab, and across by one character in any other case

## Unsafely deconstructing SrcLoc

srcLocFile :: SrcLoc -> FastString

Gives the filename of the `SrcLoc` if it is available, otherwise returns a dummy value

srcLocLine :: SrcLoc -> Int

Raises an error when used on a bad `SrcLoc`

srcLocCol :: SrcLoc -> Int

Raises an error when used on a bad `SrcLoc`

## Misc. operations on SrcLoc

pprDefnLoc :: SrcSpan -> SDoc

Pretty prints information about the `SrcSpan` in the style defined at ...

## Predicates on SrcLoc

isGoodSrcLoc :: SrcLoc -> Bool

Good `SrcLoc`s have precise information about their location

# SrcSpan

data SrcSpan

A SrcSpan delimits a portion of a text file. It could be represented by a pair of (line,column) coordinates, but in fact we optimise 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 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.

Instances

Eq SrcSpan |
Data SrcSpan |
Ord SrcSpan |
Typeable SrcSpan |
Outputable SrcSpan |

## Constructing SrcSpan

mkGeneralSrcSpan :: FastString -> SrcSpan

Create a bad `SrcSpan` that has not location information

mkSrcSpan :: SrcLoc -> SrcLoc -> SrcSpan

Create a `SrcSpan` between two points in a file

noSrcSpan :: SrcSpan

wiredInSrcSpan :: SrcSpan

Built-in bad `SrcSpan`s for common sources of location uncertainty

srcLocSpan :: SrcLoc -> SrcSpan

Create a `SrcSpan` corresponding to a single point

combineSrcSpans :: SrcSpan -> SrcSpan -> SrcSpan

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

## Deconstructing SrcSpan

srcSpanStart :: SrcSpan -> SrcLoc

Returns the location at the start of the `SrcSpan` or a bad `SrcSpan` if that is unavailable

srcSpanEnd :: SrcSpan -> SrcLoc

Returns the location at the end of the `SrcSpan` or a bad `SrcSpan` if that is unavailable

srcSpanFileName_maybe :: SrcSpan -> Maybe FastString

Obtains the filename for a `SrcSpan` if it is good

## Unsafely deconstructing SrcSpan

srcSpanFile :: SrcSpan -> FastString

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

Raises an error when used on a bad `SrcSpan`

## Predicates on SrcSpan

isGoodSrcSpan :: SrcSpan -> Bool

Test if a `SrcSpan` is good, i.e. has precise location information

isOneLineSpan :: SrcSpan -> Bool

True if the span is known to straddle only one line. For bad `SrcSpan`, it returns False

# Located

data Located e

We attach SrcSpans to lots of things, so let's have a datatype for it.

Constructors

L SrcSpan e |

Instances

Functor Located |
Typeable1 Located |
Eq e => Eq (Located e) |
Data e => Data (Located e) |
Ord e => Ord (Located e) |
Outputable e => Outputable (Located e) |

## Constructing Located

noLoc :: e -> Located e

mkGeneralLocated :: String -> e -> Located e

## Deconstructing Located

getLoc :: Located e -> SrcSpan

unLoc :: Located e -> e

## Combining and comparing Located values

eqLocated :: Eq a => Located a -> Located a -> Bool

Tests whether the two located things are equal

cmpLocated :: Ord a => Located a -> Located a -> Ordering

Tests the ordering of the two located things

combineLocs :: Located a -> Located b -> SrcSpan

addCLoc :: Located a -> Located b -> c -> Located c

Combine locations from two `Located` things and add them to a third thing

leftmost_smallest :: SrcSpan -> SrcSpan -> Ordering

leftmost_largest :: SrcSpan -> SrcSpan -> Ordering

Alternative strategies for ordering `SrcSpan`s

rightmost :: SrcSpan -> SrcSpan -> Ordering

spans :: SrcSpan -> (Int, Int) -> Bool

Determines whether a span encloses a given line and column index

isSubspanOf

Arguments

:: SrcSpan | The span that may be enclosed by the other
-> SrcSpan | The span it may be enclosed by
-> Bool |

Determines whether a span is enclosed by another one