| 1 | package godoc |
| 2 | |
| 3 | import ( |
| 4 | "go/scanner" |
| 5 | "go/token" |
| 6 | "html" |
| 7 | "strings" |
| 8 | ) |
| 9 | |
| 10 | // HighlightDecl returns syntax-highlighted HTML for a Go declaration snippet. |
| 11 | // Unlike HighlightGo, this produces inline HTML without table/line-number wrapping. |
| 12 | func HighlightDecl(src string) string { |
| 13 | return highlightDecl(src, nil) |
| 14 | } |
| 15 | |
| 16 | // HighlightDeclLinked returns syntax-highlighted HTML with cross-references. |
| 17 | // Identifiers matching a key in symbols are rendered as links. |
| 18 | // The map value is the link target (e.g., "#TypeName" or a full URL). |
| 19 | func HighlightDeclLinked(src string, symbols map[string]string) string { |
| 20 | return highlightDecl(src, symbols) |
| 21 | } |
| 22 | |
| 23 | type declSpan struct { |
| 24 | offset int |
| 25 | end int |
| 26 | class string |
| 27 | ident string // non-empty for linkable identifiers |
| 28 | } |
| 29 | |
| 30 | func highlightDecl(src string, symbols map[string]string) string { |
| 31 | prefix := "package p\n" |
| 32 | full := []byte(prefix + src) |
| 33 | |
| 34 | fset := token.NewFileSet() |
| 35 | file := fset.AddFile("", fset.Base(), len(full)) |
| 36 | |
| 37 | var s scanner.Scanner |
| 38 | s.Init(file, full, nil, scanner.ScanComments) |
| 39 | |
| 40 | var spans []declSpan |
| 41 | |
| 42 | for { |
| 43 | pos, tok, lit := s.Scan() |
| 44 | if tok == token.EOF { |
| 45 | break |
| 46 | } |
| 47 | |
| 48 | offset := int(pos) - file.Base() |
| 49 | if offset < len(prefix) { |
| 50 | continue |
| 51 | } |
| 52 | |
| 53 | var class string |
| 54 | var length int |
| 55 | var ident string |
| 56 | |
| 57 | switch { |
| 58 | case tok == token.COMMENT: |
| 59 | class = "com" |
| 60 | length = len(lit) |
| 61 | case tok == token.STRING || tok == token.CHAR: |
| 62 | class = "str" |
| 63 | length = len(lit) |
| 64 | case tok == token.INT || tok == token.FLOAT || tok == token.IMAG: |
| 65 | class = "num" |
| 66 | length = len(lit) |
| 67 | case tok.IsKeyword(): |
| 68 | class = "kw" |
| 69 | length = len(tok.String()) |
| 70 | case tok == token.IDENT: |
| 71 | length = len(lit) |
| 72 | if isBuiltin(lit) { |
| 73 | class = "bi" |
| 74 | } else if symbols != nil { |
| 75 | if _, ok := symbols[lit]; ok { |
| 76 | ident = lit |
| 77 | } |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | if class != "" || ident != "" { |
| 82 | spans = append(spans, declSpan{ |
| 83 | offset: offset - len(prefix), |
| 84 | end: offset - len(prefix) + length, |
| 85 | class: class, |
| 86 | ident: ident, |
| 87 | }) |
| 88 | } |
| 89 | } |
| 90 | |
| 91 | var b strings.Builder |
| 92 | pos := 0 |
| 93 | for _, sp := range spans { |
| 94 | if sp.offset < 0 { |
| 95 | continue |
| 96 | } |
| 97 | start := sp.offset |
| 98 | end := sp.end |
| 99 | if end > len(src) { |
| 100 | end = len(src) |
| 101 | } |
| 102 | if start > pos { |
| 103 | b.WriteString(html.EscapeString(src[pos:start])) |
| 104 | } |
| 105 | |
| 106 | text := html.EscapeString(src[start:end]) |
| 107 | |
| 108 | if sp.ident != "" && (start == 0 || src[start-1] != '.') { |
| 109 | // Linkable identifier (skip qualified names like http.Client). |
| 110 | href := symbols[sp.ident] |
| 111 | b.WriteString(`<a href="`) |
| 112 | b.WriteString(html.EscapeString(href)) |
| 113 | b.WriteString(`">`) |
| 114 | b.WriteString(text) |
| 115 | b.WriteString(`</a>`) |
| 116 | } else { |
| 117 | b.WriteString(`<span class="`) |
| 118 | b.WriteString(sp.class) |
| 119 | b.WriteString(`">`) |
| 120 | b.WriteString(text) |
| 121 | b.WriteString(`</span>`) |
| 122 | } |
| 123 | |
| 124 | pos = end |
| 125 | } |
| 126 | if pos < len(src) { |
| 127 | b.WriteString(html.EscapeString(src[pos:])) |
| 128 | } |
| 129 | |
| 130 | return b.String() |
| 131 | } |
| 132 | |