GHC.Utils.Ppr

The abstract type of documents. A Doc represents a *set* of layouts. A Doc with no occurrences of Union or NoDoc represents just one layout.

The TextDetails data type

A TextDetails represents a fragment of text that will be output at some point.

A document of height and width 1, containing a literal character.

A document of height 1 containing a literal string. text satisfies the following laws:

• text s <> text t = text (s++t)

• text "" <> x = x, if x non-empty

The side condition on the last law is necessary because text "" has height 1, while empty has no height.

Some text with any width. (text s = sizedText (length s) s)

Some text, but without any width. Use for non-printing text such as a HTML or Latex tags

Empty text (one line high but no width). (emptyText = text "")

Apply parens to Doc if boolean is true.

The empty document, with no height and no width. empty is the identity for <>, <+>, $$ and $+$, and anywhere in the argument list for sep, hcat, hsep, vcat, fcat etc.

Beside. <> is associative, with identity empty.

Beside, separated by space, unless one of the arguments is empty. <+> is associative, with identity empty.

List version of <>.

List version of <+>.

Above, except that if the last line of the first argument stops at least one position before the first line of the second begins, these two lines are overlapped. For example:

   text "hi" $$ nest 5 (text "there")

lays out as

   hi   there

rather than

   hi
        there

$$ is associative, with identity empty, and also satisfies

• (x $$ y) <> z = x $$ (y <> z), if y non-empty.

Above, with no overlapping. $+$ is associative, with identity empty.

List version of $$.

Either hsep or vcat.

Either hcat or vcat.

"Paragraph fill" version of sep.

"Paragraph fill" version of cat.

Nest (or indent) a document by a given number of positions (which may also be negative). nest satisfies the laws:

• nest 0 x = x

• nest k (nest k' x) = nest (k+k') x

• nest k (x <> y) = nest k z <> nest k y

• nest k (x $$ y) = nest k x $$ nest k y

• nest k empty = empty

• x <> nest k y = x <> y, if x non-empty

The side condition on the last law is needed because empty is a left identity for <>.

hang d1 n d2 = sep [d1, nest n d2]

Apply hang to the arguments if the first Doc is not empty.

punctuate p [d1, ... dn] = [d1 <> p, d2 <> p, ... dn-1 <> p, dn]

Returns True if the document is empty

A rendering style.

The default style (mode=PageMode False, lineLength=100, ribbonsPerLine=1.5).

Render the Doc to a String using the given Style.

Rendering mode.

The general rendering interface.

Default TextDetails printer