go.talks/pkg/present: include line numbers in output HTML
Also refactor HTML code generation to be line and template based.
R=golang-dev, dvyukov, r
CC=golang-dev
https://golang.org/cl/10539043
diff --git a/pkg/present/code.go b/pkg/present/code.go
index 367e4b2..4d62d78 100644
--- a/pkg/present/code.go
+++ b/pkg/present/code.go
@@ -5,13 +5,14 @@
package present
import (
+ "bufio"
+ "bytes"
"fmt"
"html/template"
"path/filepath"
"regexp"
"strconv"
"strings"
- "unicode"
)
// Is the playground available?
@@ -37,8 +38,11 @@
// The input line is a .code or .play entry with a file name and an optional HLfoo marker on the end.
// Anything between the file and HL (if any) is an address expression, which we treat as a string here.
// We pick off the HL first, for easy parsing.
-var highlightRE = regexp.MustCompile(`\s+HL([a-zA-Z0-9_]+)?$`)
-var codeRE = regexp.MustCompile(`\.(code|play)\s+([^\s]+)(\s+)?(.*)?$`)
+var (
+ highlightRE = regexp.MustCompile(`\s+HL([a-zA-Z0-9_]+)?$`)
+ hlCommentRE = regexp.MustCompile(`(.+) // HL(.*)$`)
+ codeRE = regexp.MustCompile(`\.(code|play)\s+([^\s]+)(\s+)?(.*)?$`)
+)
func parseCode(ctx *Context, sourceFile string, sourceLine int, cmd string) (Elem, error) {
cmd = strings.TrimSpace(cmd)
@@ -85,44 +89,91 @@
hi++
}
}
- text := string(textBytes[lo:hi])
- // Clear ommitted lines.
- text = skipOMIT(text)
+ lines := codeLines(textBytes, lo, hi)
- // Replace tabs by spaces, which work better in HTML.
- text = strings.Replace(text, "\t", " ", -1)
+ for i, line := range lines {
+ // Replace tabs by spaces, which work better in HTML.
+ line.L = strings.Replace(line.L, "\t", " ", -1)
- // Clear trailing newlines.
- text = strings.TrimRight(text, "\n")
+ // Highlight lines that end with "// HL[highlight]"
+ // and strip the magic comment.
+ if m := hlCommentRE.FindStringSubmatch(line.L); m != nil {
+ line.L = m[1]
+ line.HL = m[2] == highlight
+ }
- // Escape the program text for HTML.
- text = template.HTMLEscapeString(text)
+ lines[i] = line
+ }
- // Highlight and span-wrap lines.
- text = "<pre>" + highlightLines(text, highlight) + "</pre>"
+ data := &codeTemplateData{Lines: lines}
// Include before and after in a hidden span for playground code.
if play {
- text = hide(skipOMIT(string(textBytes[:lo]))) +
- text + hide(skipOMIT(string(textBytes[hi:])))
+ data.Prefix = textBytes[:lo]
+ data.Suffix = textBytes[hi:]
}
- // Include the command as a comment.
- text = fmt.Sprintf("<!--{{%s}}\n-->%s", cmd, text)
-
- return Code{Text: template.HTML(text), Play: play}, nil
+ var buf bytes.Buffer
+ if err := codeTemplate.Execute(&buf, data); err != nil {
+ return nil, err
+ }
+ return Code{Text: template.HTML(buf.String()), Play: play}, nil
}
-// skipOMIT turns text into a string, dropping lines ending with OMIT.
-func skipOMIT(text string) string {
- lines := strings.SplitAfter(text, "\n")
- for k := range lines {
- if strings.HasSuffix(lines[k], "OMIT\n") {
- lines[k] = ""
+type codeTemplateData struct {
+ Lines []codeLine
+ Prefix, Suffix []byte
+}
+
+var leadingSpaceRE = regexp.MustCompile(`^[ \t]*`)
+
+var codeTemplate = template.Must(template.New("code").Funcs(template.FuncMap{
+ "trimSpace": strings.TrimSpace,
+ "leadingSpace": leadingSpaceRE.FindString,
+}).Parse(codeTemplateHTML))
+
+const codeTemplateHTML = `
+{{with .Prefix}}<pre style="display: none"><span>{{printf "%s" .}}</span></pre>{{end}}
+
+<pre>{{range .Lines}}<span num="{{.N}}">{{/*
+ */}}{{if .HL}}{{leadingSpace .L}}<b>{{trimSpace .L}}</b>{{/*
+ */}}{{else}}{{.L}}{{end}}{{/*
+*/}}</span>
+{{end}}</pre>
+
+{{with .Suffix}}<pre style="display: none"><span>{{printf "%s" .}}</span></pre>{{end}}
+`
+
+// codeLine represents a line of code extracted from a source file.
+type codeLine struct {
+ L string // The line of code.
+ N int // The line number from the source file.
+ HL bool // Whether the line should be highlighted.
+}
+
+// codeLines takes a source file and returns the lines that
+// span the byte range specified by start and end.
+// It discards lines that end in "OMIT".
+func codeLines(src []byte, start, end int) (lines []codeLine) {
+ startLine := 1
+ for i, b := range src {
+ if i == start {
+ break
+ }
+ if b == '\n' {
+ startLine++
}
}
- return strings.Join(lines, "")
+ s := bufio.NewScanner(bytes.NewReader(src[start:end]))
+ for n := startLine; s.Scan(); n++ {
+ l := s.Text()
+ if strings.HasSuffix(l, "OMIT") {
+ continue
+ }
+ lines = append(lines, codeLine{L: l, N: n})
+ }
+ return
}
func parseArgs(name string, line int, args []string) (res []interface{}, err error) {
@@ -256,35 +307,3 @@
}
return 0, fmt.Errorf("unrecognized pattern: %q", pattern)
}
-
-var hlRE = regexp.MustCompile(`(.+) // HL(.*)$`)
-
-// highlightLines emboldens lines that end with "// HL" and
-// wraps any other lines in span tags.
-func highlightLines(text, label string) string {
- lines := strings.Split(text, "\n")
- for i, line := range lines {
- m := hlRE.FindStringSubmatch(line)
- if m == nil {
- continue
- }
- line := m[1]
- if m[2] != "" && m[2] != label {
- lines[i] = line
- continue
- }
- space := ""
- if j := strings.IndexFunc(line, func(r rune) bool {
- return !unicode.IsSpace(r)
- }); j > 0 {
- space = line[:j]
- line = line[j:]
- }
- lines[i] = space + "<b>" + line + "</b>"
- }
- return strings.Join(lines, "\n")
-}
-
-func hide(text string) string {
- return fmt.Sprintf(`<pre style="display: none">%s</pre>`, template.HTMLEscapeString(text))
-}
diff --git a/present/js/play.js b/present/js/play.js
index c815ae1..a30ca74 100644
--- a/present/js/play.js
+++ b/present/js/play.js
@@ -16,7 +16,7 @@
var s = "";
for (var i = 0; i < node.childNodes.length; i++) {
var n = node.childNodes[i];
- if (n.nodeType === 1 && n.tagName === "PRE") {
+ if (n.nodeType === 1 && n.tagName === "SPAN" && n.className != "number") {
var innerText = n.innerText === undefined ? "textContent" : "innerText";
s += n[innerText] + "\n";
continue;
