fancyfmt

README

fancyfmt

A formatter for Go code with bells and whistles

Installation

• Use

  go get github.com/sirkon/fancyfmt
  

  to get a library as a dependency of your custom formatter.

• Type

  go install github.com/sirkon/cmd/fancyfmt@latest
  

  to install a ready to use formatter

Description

fancyfmt is a

• library to make gofmt compliant formatters
• a ready to use formatter

Brief functionality

• Imports grouping and sorting. Import paths are:
  • Joined in one import declaration (except "C", which is always alone)
  • Splitted in groups (can be tweaked with custom imports grouper)
  • Sorted lexicographically within each group
• Provides default formatting for
  • Multiline functions declarations
  • Multiline calls
  • Multiline composite literals, slices and arrays get a special care at that
  • Multiline chaining

Screencast

Remarks

• fancyfmt stores a cache of packages from standard library in a os.TempDir() directory. This was done to speedup things as package.Load(cfg, "std") is slow, about 0.2s on my machine, cached access is about ten times faster. You may notice a slugishness in case of the first formatting in the screencast, that is it. The further formats are much faster.
• fancyfmt mutates []byte{…} literals if they only have numbers replacing them with hex numbers.
• You may fix composite literals formatting (except the new line before the first item and after the last one) by adding a comment after an element.

Documentation

Index

• func Format(fset *token.FileSet, file *ast.File, content []byte, grouper ImportsGrouper) (io.Reader, error)
• type ImportsGrouper
  • func DefaultImportGroupsWithCurrent(current string) ImportsGrouper
  • func DefaultImportsGrouper() (ImportsGrouper, error)

Functions

func Format

func Format(fset *token.FileSet, file *ast.File, content []byte, grouper ImportsGrouper) (io.Reader, error)

Format formats given AST tree

Types

type ImportsGrouper

type ImportsGrouper interface {
	Weight(path string) int
}

ImportsGrouper a facility to give an import path a certain weight what will be used to group a set of imports by it, i.e. import paths with the same weight will be in one groups of imports

func DefaultImportGroupsWithCurrent

func DefaultImportGroupsWithCurrent(current string) ImportsGrouper

DefaultImportGroupsWithCurrent the same s DefaultImportsGroups just no current package set

func DefaultImportsGrouper

func DefaultImportsGrouper() (ImportsGrouper, error)

DefaultImportsGrouper provides an import grouper with a policy that is supposed to be the default:

"C" - 0
Standard library - 1
3rd party - 2
Current project - 3
Relative imports - 4

It tried to determine a current project once called and may return an error if it failed to detect it. Use DefaultImportGroupsWithCurrent if you don't need it or need to set up your own