From the FAQ:

…the program gofmt is a pretty-printer whose purpose is to enforce layout rules; it replaces the usual compendium of do’s and don’ts that allows interpretation. All the Go code in the repository has been run through gofmt.

usage: gofmt [flags] [path ...]
  -tabwidth=8: tab width
  -trace=false: print parse trace
  -r="": rewrite rule (e.g., 'α[β:len(α)] -> α[β:]')
  -debug=false: print debugging information
  -tabindent=true: indent with tabs independent of -spaces
  -l=false: list files whose formatting differs from gofmt's
  -w=false: write result to (source) file instead of stdout
  -spaces=true: align with spaces instead of tabs
  -comments=true: print comments