# Go — `github.com/minjun0219/mdwire/go`

> The Go port — Render, RenderWith, Options, Streamer, Channel and Repairs. Standard library only.

HTML: https://mdwire.minjun.dev/docs/go/

A port of the Rust core, standard library only. It passes the same corpus and is checked against
the Rust core on random inputs and real documents. Full reference:
[pkg.go.dev](https://pkg.go.dev/github.com/minjun0219/mdwire/go).

```sh
go get github.com/minjun0219/mdwire/go@latest
```

## `Render`

```go
import "github.com/minjun0219/mdwire/go"

parts := mdwire.Render(input, mdwire.TelegramHTML) // []string
```

Converts a finished document; over the limit it splits where no markup is open.

## `RenderWith`

```go
out := mdwire.RenderWith(input, mdwire.SlackMarkdown, mdwire.Options{From: mdwire.SlackMrkdwn})
out.Parts                  // []string
out.Repairs.ClosedEmphasis // see Repairs below
```

## `Options`

The zero value is the default.

```go
type Options struct {
	From  Dialect     // Markdown (zero) | SlackMrkdwn
	Limit int         // 0 = the channel's Limit(); below MinLimit (256) is raised
	HTML  HTMLOptions // the HTML channel only
}

type HTMLOptions struct {
	LineBreaks LineBreaks // LineBreaksBR (zero) | LineBreaksSpace
	Images     Images     // ImagesLink (zero) | ImagesLoad
	Schemes    []string   // nil = http, https, mailto; a list replaces the default; empty (non-nil) allows none
}
```

## `Streamer`

```go
s := mdwire.NewStreamer(mdwire.SlackMarkdown)
var out []byte
for _, chunk := range chunks {
	s.PushTo(chunk, &out) // no allocation per chunk
}
s.FinishTo(&out)
```

| | |
|---|---|
| `NewStreamer(ch)` · `NewStreamerWith(ch, opts)` | One streamer per document. |
| `PushTo(chunk, *[]byte)` · `Push(chunk) string` | What is safe to send now. `PushTo` is the allocation-free form. |
| `FinishTo(*[]byte)` · `Finish() string` | The rest, with open markup closed. |
| `PreviewTo(*[]byte)` · `Preview() string` | The tail to append when redrawing the whole message. |
| `CloseOpenTo(*[]byte)` · `CloseOpen() string` | The tail that only closes block markup already sent. |
| `Revised() bool` | After `Finish`: does the result differ from the last preview? |
| `Repairs() Repairs` | What was repaired so far. |

The contract is on [Concepts](https://mdwire.minjun.dev/docs/#the-streaming-contract).

## `Channel` and `Dialect`

```go
const ( TelegramHTML Channel = iota; SlackMarkdown; Plain; GithubMarkdown; HTML; NotionMarkdown )
const ( Markdown Dialect = iota; SlackMrkdwn )
```

The numeric values are not the order of `Channels()`; use names to
store or send a channel.

| | |
|---|---|
| `Channels() []Channel` | Every channel. |
| `(Channel) Name() string` · `ParseChannel(string) (Channel, bool)` | The string names. |
| `(Channel) Limit() int` | The part limit. |
| `(Dialect) Name() string` · `ParseDialect(string) (Dialect, bool)` | `"markdown"`, `"slack-mrkdwn"`. |

## `Repairs`

```go
type Repairs struct {
	ClosedEmphasis, ClosedFence, RevertedCodeSpan, DroppedMarker int
	// channel rewrites
	EscapedChar, TagEmphasis, StrippedHTML, RewrittenBullet, RewrittenTable, ConvertedMarker int
}
```

`Repaired()` — did it repair anything (the first four). `Changed()` — did it repair
or rewrite anything. What each field counts: [Concepts](https://mdwire.minjun.dev/docs/#the-repair-report).

## Widths

`CharWidth(rune) int` and `StrWidth(string) int` — the display widths used for monospace tables.

## CLI

`go install github.com/minjun0219/mdwire/go/cmd/mdwire@latest` installs the same CLI as the Rust one,
with the same flags except `-V`/`--version`. See [CLI](https://mdwire.minjun.dev/docs/cli/).