ghc-7.10.2: The GHC API

Safe HaskellNone
LanguageHaskell2010

SrcLoc

Contents

Description

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

Synopsis

SrcLoc

data RealSrcLoc

Represents a single point within a file

Constructing SrcLoc

mkGeneralSrcLoc :: FastString -> SrcLoc

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

noSrcLoc :: SrcLoc

Built-in "bad" SrcLoc values for particular locations

generatedSrcLoc :: SrcLoc

Built-in "bad" SrcLoc values for particular locations

interactiveSrcLoc :: SrcLoc

Built-in "bad" SrcLoc values for particular locations

advanceSrcLoc :: RealSrcLoc -> Char -> RealSrcLoc

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 :: RealSrcLoc -> FastString

Gives the filename of the RealSrcLoc

srcLocLine :: RealSrcLoc -> Int

Raises an error when used on a "bad" SrcLoc

srcLocCol :: RealSrcLoc -> Int

Raises an error when used on a "bad" SrcLoc

SrcSpan

data RealSrcSpan

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.

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

mkRealSrcSpan :: RealSrcLoc -> RealSrcLoc -> RealSrcSpan

Create a SrcSpan between two points in a file

noSrcSpan :: SrcSpan

Built-in "bad" SrcSpans for common sources of location uncertainty

wiredInSrcSpan :: SrcSpan

Built-in "bad" SrcSpans 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

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

containsSpan :: RealSrcSpan -> RealSrcSpan -> Bool

Tests whether the first span "contains" the other span, meaning that it covers at least as much source code. True where spans are equal.

Located

data GenLocated l e

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

Constructors

L l e 

Instances

Constructing Located

noLoc :: e -> Located e

Deconstructing Located

getLoc :: GenLocated l e -> l

unLoc :: GenLocated l 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

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

Alternative strategies for ordering SrcSpans

leftmost_largest :: SrcSpan -> SrcSpan -> Ordering

Alternative strategies for ordering SrcSpans

rightmost :: SrcSpan -> SrcSpan -> Ordering

Alternative strategies for ordering SrcSpans

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