e42b097629
This commit inlines https://github.com/tj/go-termd for a few reasons: - off the shelf it relies on a broken, erroneously released version of blackfriday (a markdown parser) - based on discussion with ampinsk, there are some tweaks we'd like to make to markdown rendering beyond what the library exposes now - it's a small library (around 300 sloc) This commit only: - messes with go.mod to fix the blackfriday issues - adds an inclusion note - renames the package
122 lines
3.2 KiB
Go
122 lines
3.2 KiB
Go
// Package markdown provides terminal markdown rendering,
|
|
// with code block syntax highlighting support.
|
|
// This package is sourced from https://github.com/tj/go-termd under the terms of the MIT license.
|
|
// It was inlined to work around some dependency issues.
|
|
package markdown
|
|
|
|
import (
|
|
"fmt"
|
|
"strings"
|
|
|
|
"github.com/kr/text"
|
|
"github.com/mitchellh/go-wordwrap"
|
|
blackfriday "github.com/russross/blackfriday/v2"
|
|
)
|
|
|
|
// Compiler is the markdown to text compiler. The zero value can be used.
|
|
type Compiler struct {
|
|
// Columns is the number of columns to wrap text, defaulting to 90.
|
|
Columns int
|
|
|
|
// Markdown is an optional instance of a blackfriday markdown parser,
|
|
// defaulting to one with CommonExtensions enabled.
|
|
Markdown *blackfriday.Markdown
|
|
|
|
// SyntaxHighlighter is an optional syntax highlighter for code blocks,
|
|
// using the low-level SyntaxHighlighter interface, or SyntaxTheme map.
|
|
SyntaxHighlighter
|
|
|
|
inBlockQuote bool
|
|
inList bool
|
|
}
|
|
|
|
// Compile returns a terminal-styled plain text representation of a markdown string.
|
|
func (c *Compiler) Compile(s string) string {
|
|
if c.Markdown == nil {
|
|
c.Markdown = blackfriday.New(blackfriday.WithExtensions(blackfriday.CommonExtensions))
|
|
}
|
|
|
|
if c.Columns == 0 {
|
|
c.Columns = 90
|
|
}
|
|
|
|
if c.SyntaxHighlighter == nil {
|
|
c.SyntaxHighlighter = SyntaxTheme{}
|
|
}
|
|
|
|
n := c.Markdown.Parse([]byte(s))
|
|
return c.visit(n)
|
|
}
|
|
|
|
// visit returns a compiled node string.
|
|
func (c *Compiler) visit(n *blackfriday.Node) (s string) {
|
|
switch n.Type {
|
|
case blackfriday.Document:
|
|
s = c.visit(n.FirstChild)
|
|
case blackfriday.BlockQuote:
|
|
prev := c.inBlockQuote
|
|
c.inBlockQuote = true
|
|
s = c.visit(n.FirstChild)
|
|
s = fmt.Sprintf("\033[38;5;102m%s\033[m", s)
|
|
c.inBlockQuote = prev
|
|
case blackfriday.List:
|
|
prev := c.inList
|
|
c.inList = true
|
|
s = fmt.Sprintf("%s\n", c.visit(n.FirstChild))
|
|
c.inList = prev
|
|
case blackfriday.Item:
|
|
s = fmt.Sprintf(" - %s", c.visit(n.FirstChild))
|
|
case blackfriday.Paragraph:
|
|
s = c.visit(n.FirstChild)
|
|
if c.inList {
|
|
s += "\n"
|
|
} else {
|
|
s = wordwrap.WrapString(s, uint(c.Columns))
|
|
s = text.Indent(s, " ")
|
|
s += "\n\n"
|
|
}
|
|
case blackfriday.Heading:
|
|
h := strings.Repeat("#", n.HeadingData.Level)
|
|
t := c.visit(n.FirstChild)
|
|
s = fmt.Sprintf("\033[1m%s %s\033[m\n\n", h, t)
|
|
case blackfriday.HorizontalRule:
|
|
s = fmt.Sprintf(" %s\n\n", strings.Repeat("─", c.Columns))
|
|
case blackfriday.Emph:
|
|
s = c.visit(n.FirstChild)
|
|
if !c.inBlockQuote {
|
|
s = fmt.Sprintf("\033[3m%s\033[m", s)
|
|
}
|
|
case blackfriday.Strong:
|
|
s = c.visit(n.FirstChild)
|
|
if !c.inBlockQuote {
|
|
s = fmt.Sprintf("\033[1m%s\033[m", s)
|
|
}
|
|
case blackfriday.Link:
|
|
s = c.visit(n.FirstChild)
|
|
d := string(n.LinkData.Destination)
|
|
if s != d {
|
|
s = fmt.Sprintf("%s (%s)", s, d)
|
|
}
|
|
case blackfriday.Image:
|
|
s = string(n.LinkData.Destination)
|
|
case blackfriday.Text:
|
|
s = string(n.Literal)
|
|
case blackfriday.CodeBlock:
|
|
lang := string(n.CodeBlockData.Info)
|
|
s = string(n.Literal)
|
|
s = highlight(s, lang, c.SyntaxHighlighter)
|
|
s = fmt.Sprintf("%s\n", text.Indent(s, " "))
|
|
case blackfriday.Code:
|
|
s = fmt.Sprintf("\033[38;5;102m`%s`\033[m", string(n.Literal))
|
|
case blackfriday.HTMLSpan:
|
|
// ignore
|
|
default:
|
|
s = fmt.Sprintf("<unhandled: %v>", n)
|
|
}
|
|
|
|
if n.Next != nil {
|
|
s += c.visit(n.Next)
|
|
}
|
|
|
|
return
|
|
}
|