BNFC.PrettyPrint

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.

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.

Beside. <> is associative, with identity empty.

Rendering mode.

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.

Render the Doc to a String using the default Style (see style).

Returns True if the document is empty

Above, with no overlapping. $+$ 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 $$.

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 x <> 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 <>.

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

A rendering style. Allows us to specify constraints to choose among the many different rendering options.

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

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.

Either hcat or vcat.

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

"Paragraph fill" version of cat.

"Paragraph fill" version of sep.

The general rendering interface. Please refer to the Style and Mode types for a description of rendering mode, line length and ribbons.

List version of <+>.

Same as text. Used to be used for Bytestrings.

Render the Doc to a String using the given Style.

Either hsep or vcat.

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

Overloaded function pretty.

Put parens around document if given condition is true.

>>> parensIf True "foo"(foo)

>>> parensIf False "bar"bar

Render as String.

Separate vertically by a blank line.

>>> "foo" $++$ "bar"foobar

>>> "foo" $++$ emptyfoo

List version of $++$.

>>> vsep [ "foo", nest 4 "bar" ]foo    bar

>>> vsep []

List version of PrettyPrint.$+$.

>>> vcat' [text "abc", nest 4 (text "def")]abc    def

Pretty print separator with = (for assignments...).

>>> "a" <=> "123"a = 123

Print a list of 0-1 elements on the same line as some preamble and from 2 elements on the following lines, indented.

>>> prettyList 2 ("foo" <+> equals) lbrack rbrack comma []foo = []>>> prettyList 2 ("foo" <+> equals) lbrack rbrack comma [ "a" ]foo = [a]>>> prettyList 2 ("foo" <+> equals) lbrack rbrack comma [ "a", "b" ]foo =  [ a  , b  ]

Used in the Agda backend.

Code block. A block of C/Java code, surrounded by {} and indented.

>>> codeblock 4 ["abc", "def"]{    abc    def}

Used in the C backend.