Overview

Simple system for writing HTML/XML as Go code. Better-performing replacement for html/template and text/template. Vaguely inspired by JS library https://github.com/mitranim/prax, but uses a different design.

Features / benefits:

• No weird special language to learn.
• Use actual Go code.
• Use normal Go conditionals.
• Use normal Go loops.
• Use normal Go functions.
• Benefit from static typing.
• Benefit from Go code analysis.
• Benefit from Go performance.
• Tiny and dependency-free (only stdlib).

TOC

• Usage
• Performance
• Changelog
• License
• Misc

Usage

API docs: https://pkg.go.dev/github.com/mitranim/gax.

package main

import (
  "fmt"
  "github.com/mitranim/gax"
)

type A = gax.A

func main() {
  bui := gax.Bui(gax.Doctype)

  render(bui.E, mockDat)

  fmt.Println(bui)
  // 
Posts
Post0
Post1
}

func render(E gax.E, dat Dat) {
  E(`html`, A{{`lang`, `en`}}, func() {
    E(`head`, nil, func() {
      E(`meta`, A{{`charset`, `utf-8`}})
      E(`link`, A{{`rel`, `icon`}, {`href`, `data:;base64,=`}})

      // Use normal Go conditionals.
      if dat.Title != "" {
        E(`title`, nil, dat.Title)
      } else {
        E(`title`, nil, `test markup`)
      }
    })

    E(`body`, nil, func() {
      E(`h1`, A{{`class`, `title`}}, `Posts`)

      // Use normal Go loops.
      for _, post := range dat.Posts {
        E(`h2`, nil, post)
      }
    })
  })
}

var mockDat = Dat{
  Title: `Posts`,
  Posts: []string{`Post0`, `Post1`},
}

type Dat struct {
  Title string
  Posts []string
}

Performance

For mostly-static templates, Gax loses to html/template but remains more than fast enough. For anything dynamic, Gax seems to perform several times better. The more complicated a template is, the better it gets.

The benchmark in gax_bench_test.go is intentionally naive, avoiding some Gax optimizations in order to mimic actual user code.

go test -bench . -benchmem

cpu: Intel(R) Core(TM) i9-8950HK CPU @ 2.90GHz
Benchmark_static_gax-12             331562        3404 ns/op      1544 B/op       25 allocs/op
Benchmark_static_template-12       6006633       193.4 ns/op       480 B/op        3 allocs/op
Benchmark_dynamic_gax-12             69954       17127 ns/op      8872 B/op      162 allocs/op
Benchmark_dynamic_template-12         9532      131470 ns/op     61791 B/op     1373 allocs/op

Changelog

v0.1.4

Bui.Child also supports func(E).

v0.1.3

Added Bui.With and Ebui.

v0.1.2

Minor syntactic bugfix.

v0.1.1

Converted methods .WriteTo(*[]byte) methods to .Append([]byte) []byte for better compliance with established interfaces.

v0.1.0

Init.

License

https://unlicense.org

Misc

I'm receptive to suggestions. If this library almost satisfies you but needs changes, open an issue or chat me up. Contacts: https://mitranim.com/#contacts