Easy_format: indentation made easy.
This module provides a functional, simplified layer over the Format module of the standard library.
Input data must be first modelled as a tree using 3 kinds of nodes:
Atoms represent any text that is guaranteed to be printed as-is. Lists can model any sequence of items such as arrays of data or lists of definitions that are labelled with something like "int main", "let x =" or "x:".
List wrapping conditions:
`Wrap_atoms
: wrap if the list contains only atoms`Always_wrap
: always wrap when needed`Never_wrap
: never wrap,
i.e. the list is either horizontal or vertical`Force_breaks
: align vertically,
i.e. always break line between list items and
align the left edge of each item.`No_breaks
: align horizontally,
i.e. never break line between list items
#
atom_style
| : style_name option | ; | (* | Default: None | *) |
#
space_after_opening
| : bool | ; | (* | Whether there must be some whitespace
after the opening string.
Default: true | *) |
#
space_after_separator
| : bool | ; | (* | Whether there must be some whitespace
after the item separators.
Default: true | *) |
#
space_before_separator
| : bool | ; | (* | Whether there must be some whitespace
before the item separators.
Default: false | *) |
#
separators_stick_left
| : bool | ; | (* | Whether the separators must
stick to the item on the left.
Default: true | *) |
#
space_before_closing
| : bool | ; | (* | Whether there must be some whitespace
before the closing string.
Default: true | *) |
#
stick_to_label
| : bool | ; | (* | Whether the opening string should be fused
with the preceding label.
Default: true | *) |
#
align_closing
| : bool | ; | (* | Whether the beginning of the
closing string must be aligned
with the beginning of the opening string
(stick_to_label = false) or
with the beginning of the label if any
(stick_to_label = true).
Default: true | *) |
#
wrap_body
| : wrap | ; | (* | Defines under which conditions the list body
may be wrapped, i.e. allow several lines
and several list items per line.
Default: `Wrap_atom_list | *) |
#
indent_body
| : int | ; | (* | Extra indentation of the list body.
Default: 2 | *) |
#
list_style
| : style_name option | ; | (* | Default: None | *) |
#
opening_style
| : style_name option | ; | (* | Default: None | *) |
#
body_style
| : style_name option | ; | (* | Default: None | *) |
#
separator_style
| : style_name option | ; | (* | Default: None | *) |
#
closing_style
| : style_name option | ; | (* | Default: None | *) |
List-formatting parameters. Always derive a new set of parameters from an existing record. See Easy_format.list.
Default list-formatting parameters, using the default values described in the type definition above.
In order to make code compatible with future versions of the library,
the record inheritance syntax should be used, e.g.
{ list with align_closing = false }
.
If new record fields are added, the program would still compile
and work as before.
#
space_after_label
| : bool | ; | (* | Whether there must be some whitespace
after the label.
Default: true | *) |
#
indent_after_label
| : int | ; | (* | Extra indentation before the item
that comes after a label.
Default: 2 | *) |
#
label_style
| : style_name option | ; | (* | Default: None | *) |
Label-formatting parameters. Always derive a new set of parameters from an existing record. See Easy_format.label.
Default label-formatting parameters, using the default values described in the type definition above.
In order to make code compatible with future versions of the library,
the record inheritance syntax should be used, e.g.
{ label with indent_after_label = 0 }
.
If new record fields are added, the program would still compile
and work as before.
(* | Plain string normally without line breaks. | *) | |
(* | List ((opening, separator, closing, param), nodes) | *) | |
(* | Label ((label, param), node) : labelled node. | *) | |
(* | User-defined printing function that allows to use the Format module directly if necessary. It is responsible for leaving the formatter in a clean state. | *) |
The type of the tree to be pretty-printed. Each node contains its own formatting parameters.
Detail of a list node
List ((opening, separator, closing, param), nodes)
:
opening
: opening string such as "{"
"["
"("
"begin"
""
etc.separator
: node separator such as ";"
","
""
"+"
"|"
etc.closing
: closing string such as "}"
"]"
")"
"end"
""
etc.nodes
: elements of the list.