dchapes / fmtless

A toolkit for replacing fmt's output funcs, plus fmt-free stdlib replacements

fmtless: All the convenience of fmt without the bloat

by Cathal Garvey, ©2016, Released under the GNU AGPLv3 or later

Why Avoid fmt?

The fmt library is a super-rich way to present and parse data in your Go application. I love fmt; everyone loves fmt!

However, fmt is really big, adding a large premium to output binaries. For straight compilation to static binaries, this isn't usually a dealbreaker (cf. the success of Go overall).

However, in edge-cases, like embedding Go in storage-constrained devices, or shipping a collection of small apps in Go, or when transpiling to JS, the premium can be really costly. In my own experience, removing fmt from a GopherJS application removed 0.5Mb from the output Javascript, which can be a huge deal when shipping JS.

Most fmt imports seem to use it only for output, or for errors. So, fmtless is a toolkit for rapidly porting software using fmt for output and errors, hopefully only requiring a single-line change: instead of import "fmt", just do import "github.com/cathalgarvey/fmtless"!

fmtless also has mirrors of Go's standard libraries with fmt replaced with fmtless, to reduce binary size. Try switching over and see if it makes a difference to your application!

At present the included stdlibs in this repo are lifted directly from my local install. In the future I plan to have a script pull chosen libraries directly from the most recent tag/release of Go and converts them.

Usage

Right now, it's just replace fmt with github.com/cathalgarvey/fmtless. For stdlibs, likewise, it's just "prepend your stdlib imports with github.com/cathalgarvey/fmtless". Currently supported:

• encoding/json (was only using stdlibs for errors)
• encoding/xml (was only using stdlibs for errors)
• net/url (was only using stdlibs for errors)