texthtml

type Config struct {
	Line       int       // if >= 1, number lines beginning with number Line, with <span class="ln">
	GoComments bool      // mark comments in Go text with <span class="comment">
	Playground bool      // format for playground sample
	Highlight  string    // highlight matches for this regexp with <span class="highlight">
	HL         string    // highlight lines that end with // HL (x/tools/present convention)
	Selection  Selection // mark selected spans with <span class="selection">
	AST        ast.Node  // link uses to declarations, assuming text is formatting of AST
	OldDocs    bool      // emit links to ?m=old docs
}

type Selection func() Span

type Span struct {
	Start, End int
}