GHC.Utils.Outputable

Class designating that some type has an SDoc representation

When we print a binder, we often want to print its type too. The OutputableBndr class encapsulates this idea.

Outputable class with an additional environment value

See Note [The OutputableP class]

BindingSite is used to tell the thing that prints binder what language construct is binding the identifier. This can be used to decide how much info to print. Also see Note [Binding-site specific printing] in GHC.Core.Ppr

A superclass for IsLine and IsDoc that provides an identity, empty, as well as access to the shared SDocContext.

See Note [The outputable class hierarchy] for more details.

A class of types that represent a single logical line of text, with support for horizontal composition.

See Note [HLine versus HDoc] and Note [The outputable class hierarchy] for more details.

A class of types that represent a multiline document, with support for vertical composition.

See Note [HLine versus HDoc] and Note [The outputable class hierarchy] for more details.

Represents a single line of output that can be efficiently printed directly to a Handle (actually a BufHandle). See Note [SDoc versus HDoc] and Note [HLine versus HDoc] for more details.

Represents a (possibly empty) sequence of lines that can be efficiently printed directly to a Handle (actually a BufHandle). See Note [SDoc versus HDoc] and Note [HLine versus HDoc] for more details.

Represents a pretty-printable document.

To display an SDoc, use printSDoc, printSDocLn, bufLeftRenderSDoc, or renderWithContext. Avoid calling runSDoc directly as it breaks the abstraction layer.

Wrapper for types having a Outputable instance when an OutputableP instance is required.

Returns the separated concatenation of the pretty printed things.

Returns the comma-separated concatenation of the pretty printed things.

Returns the comma-separated concatenation of the quoted pretty printed things.

[x,y,z]  ==>  `x', `y', `z'

Indent SDoc some specified amount

doublePrec p n shows a floating point number n with p digits of precision after the decimal point.

Join two SDoc together vertically

A paragraph-fill combinator. It's much like sep, only it keeps fitting things on one line until it can't fit any more.

This behaves like fsep, but it uses <> for horizontal composition rather than <+>

This behaves like hang, but does not indent the second document when the header is empty.

Punctuate a list, e.g. with commas and dots.

sep $ punctuateFinal comma dot [text "ab", text "cd", text "ef"]
ab, cd, ef.

Converts an integer to a verbal index:

speakNth 1 = text "first"
speakNth 5 = text "fifth"
speakNth 21 = text "21st"

Converts an integer to a verbal multiplicity:

speakN 0 = text "none"
speakN 5 = text "five"
speakN 10 = text "10"

Converts an integer and object description to a statement about the multiplicity of those objects:

speakNOf 0 (text "melon") = text "no melons"
speakNOf 1 (text "melon") = text "one melon"
speakNOf 3 (text "melon") = text "three melons"

Determines the pluralisation suffix appropriate for the length of a list:

plural [] = char 's'
plural ["Hello"] = empty
plural ["Hello", "World"] = char 's'

Determines the singular verb suffix appropriate for the length of a list:

singular [] = empty
singular["Hello"] = char 's'
singular ["Hello", "World"] = empty

Like plural, but for sets.

Determines the form of to be appropriate for the length of a list:

isOrAre [] = text "are"
isOrAre ["Hello"] = text "is"
isOrAre ["Hello", "World"] = text "are"

Determines the form of to do appropriate for the length of a list:

doOrDoes [] = text "do"
doOrDoes ["Hello"] = text "does"
doOrDoes ["Hello", "World"] = text "do"

Determines the form of possessive appropriate for the length of a list:

itsOrTheir [x]   = text "its"
itsOrTheir [x,y] = text "their"
itsOrTheir []    = text "their"  -- probably avoid this

Determines the form of subject appropriate for the length of a list:

thisOrThese [x]   = text "This"
thisOrThese [x,y] = text "These"
thisOrThese []    = text "These"  -- probably avoid this

"has" or "have" depending on the length of a list.

it or they, depeneding on the length of the list.

itOrThey [x]   = text "it"
itOrThey [x,y] = text "they"
itOrThey []    = text "they"  -- probably avoid this

Apply the given colour/style for the argument.

Only takes effect if colours are enabled.

The analog of printDoc_ for SDoc, which tries to make sure the terminal doesn't get screwed up by the ANSI color codes if an exception is thrown during pretty-printing.

Like printSDoc but appends an extra newline.

An efficient variant of printSDoc specialized for LeftMode that outputs to a BufHandle.

Special combinator for showing character literals.

Special combinator for showing string literals.

Special combinator for showing bytestring literals.

Special combinator for showing unboxed literals.

Normalise, escape and render a string representing a path

e.g. "c:\whatever"

When printing code that contains original names, we need to map the original names back to something the user understands. This is the purpose of the triple of functions that gets passed around when rendering SDoc.

Given a Name's Module and OccName, decide whether and how to qualify it.

For a given module, we need to know whether to print it with a package name to disambiguate it.

For a given package, we need to know whether to print it with the component id to disambiguate it.

Given a promoted data constructor, decide whether to print a tick to disambiguate the namespace.

Flags that affect whether a promotion tick is printed.

NB: This won't ever show package IDs