dfmt

dfmt is a formatter for D source code

Status

dfmt is beta quality. Make backups of your files or use source control when using the --inplace option.

Installation

Installing with DUB

> dub run dfmt -- -h

Building from source using Make

Clone the repository
Run git submodule update --init --recursive in the dfmt directory
To compile with DMD, run make in the dfmt directory. To compile with LDC, run make ldc instead. The generated binary will be placed in dfmt/bin/.

Building from source using dub

Clone the repository
run dub build --build=release, optionally with --compiler=ldc2

Using

By default, dfmt reads its input from stdin and writes to stdout. If a file name is specified on the command line, input will be read from the file instead, and output will be written to stdout.

dfmt uses EditorConfig files for configuration. If you run dfmt on a source file it will look for .editorconfig files that apply to that source file. If no file is specified on the command line, dfmt will look for .editorconfig files that would apply to a D file in the current working directory. Command line options can be used instead of .editorconfig files, or to override options found there.

Options

--help | -h: Display command line options.
--inplace | -i: A file name is required and the file will be edited in-place.
--align_switch_statements: see dfmt_align_switch_statements below
--brace_style: see dfmt_brace_style below
--compact_labeled_statements: see dfmt_compact_labeled_statements below
--end_of_line: see end_of_line below
--indent_size: see indent_size below
--indent_style | -t: see indent_style below
--max_line_length: see max_line_length below
--outdent_attributes: see dfmt_outdent_attributes below
--selective_import_space: see dfmt_selective_import_space below
--single_template_constraint_indent: see dfmt_single_template_constraint_indent below
--soft_max_line_length: see dfmt_soft_max_line_length below
--space_after_cast: see dfmt_space_after_cast below
--space_before_aa_colon: see dfmt_space_before_aa_colon below
--space_before_named_arg_colon: see dfmt_space_before_named_arg_colon below
--space_before_function_parameters: see dfmt_space_before_function_parameters below
--split_operator_at_line_end: see dfmt_split_operator_at_line_end below
--tab_width: see tab_width below
--template_constraint_style: see dfmt_template_constraint_style below
--keep_line_breaks: see dfmt_keep_line_breaks below
--single_indent: see dfmt_single_indent below
--reflow_property_chains: see dfmt_property_chains below
--space_after_keywords: see dfmt_space_after_keywords below

Example

dfmt --inplace --space_after_cast=false --max_line_length=80 \
    --soft_max_line_length=70 --brace_style=otbs file.d

Disabling formatting

Formatting can be temporarily disabled by placing the comments // dfmt off and // dfmt on around code that you do not want formatted.

void main(string[] args)
{
    bool optionOne, optionTwo, optionThree;

    // dfmt has no way of knowing that "getopt" is special, so it wraps the
    // argument list normally
    getopt(args, "optionOne", &optionOne, "optionTwo", &optionTwo, "optionThree", &optionThree);

    // dfmt off
    getopt(args,
        "optionOne", &optionOne,
        "optionTwo", &optionTwo,
        "optionThree", &optionThree);
    // dfmt on
}

Configuration

dfmt uses EditorConfig configuration files. dfmt-specific properties are prefixed with dfmt_.

Standard EditorConfig properties

Property Name	Allowed Values	Description
end_of_line	`cr`, `crlf` and `lf`	See EditorConfig documentation. When not set, `dfmt` adopts the first line ending in the input.
insert_final_newline	`true`	Not supported. `dfmt` always inserts a final newline.
charset	`UTF-8`	Not supported. `dfmt` only works correctly on UTF-8.
indent_style	`tab`, `space`	See EditorConfig documentation.
indent_size	positive integers (`4`)	See EditorConfig documentation.
tab_width	positive integers (`4`)	See EditorConfig documentation.
trim_trailing_whitespace	`true`	Not supported. `dfmt` does not emit trailing whitespace.
max_line_length	positive integers (`120`)	See EditorConfig documentation.

dfmt-specific properties

Property Name	Allowed Values	Description
dfmt_brace_style	`allman`, `otbs`, `stroustrup` or `knr`	See Wikipedia
dfmt_soft_max_line_length	positive integers (`80`)	The formatting process will usually keep lines below this length, but they may be up to max_line_length columns long.
dfmt_align_switch_statements	`true`, `false`	Align labels, cases, and defaults with their enclosing switch.
dfmt_outdent_attributes (Not yet implemented)	`true`, `false`	Decrease the indentation level of attributes.
dfmt_split_operator_at_line_end	`true`, `false`	Place operators on the end of the previous line when splitting lines.
dfmt_space_after_cast	`true`, `false`	Insert space after the closing paren of a `cast` expression.
dfmt_space_after_keywords (Not yet implemented)	`true`, `false`	Insert space after `if`, `while`, `foreach`, etc, and before the `(`.
dfmt_space_before_function_parameters	`true`, `false`	Insert space before the opening paren of a function parameter list.
dfmt_selective_import_space	`true`, `false`	Insert space after the module name and before the `:` for selective imports.
dfmt_compact_labeled_statements	`true`, `false`	Place labels on the same line as the labeled `switch`, `for`, `foreach`, or `while` statement.
dfmt_template_constraint_style	`conditional_newline_indent` `conditional_newline` `always_newline` `always_newline_indent`	Control the formatting of template constraints.
dfmt_single_template_constraint_indent	`true`, `false`	Set if the constraints are indented by a single tab instead of two. Has only an effect if the style set to `always_newline_indent` or `conditional_newline_indent`.
dfmt_space_before_aa_colon	`true`, `false`	Adds a space after an associative array key before the `:` like in older dfmt versions.
dfmt_space_before_named_arg_colon	`true`, `false`	Adds a space after a named function argument or named struct constructor argument before the `:`.
dfmt_keep_line_breaks	`true`, `false`	Keep existing line breaks if these don't violate other formatting rules.
dfmt_single_indent	`true`, `false`	Set if the code in parens is indented by a single tab instead of two.
dfmt_reflow_property_chains	`true`, `false`	Recalculate the splitting of property chains into multiple lines.
dfmt_space_after_keywords	`true`, `false`	Insert space after keywords (if,while,foreach,for, etc.).

Terminology

Braces - { and }
Brackets - [ and ]
Parenthesis / Parens - ( and )

dlang-community/dfmt