Perf/precompile regex (#687)

* perf: pre-compile regexes at package level

Move regexp.MustCompile calls from inside methods to package-level
variables in web.go (7 regexes) and loader.go (2 regexes).
This avoids repeated compilation on every invocation.

Amp-Thread-ID: https://ampcode.com/threads/T-019c79c3-ea1c-7471-b09d-be90ba0e1ca0
Co-authored-by: Amp <amp@ampcode.com>

* perf: pre-compile regexes at package level

* retain the helpful comment

---------

Co-authored-by: Amp <amp@ampcode.com>

pkg/channels/telegram.go

@@ -23,6 +23,19 @@ import (
 	"github.com/sipeed/picoclaw/pkg/voice"
 )
 
+var (
+	reHeading    = regexp.MustCompile(`^#{1,6}\s+(.+)$`)
+	reBlockquote = regexp.MustCompile(`^>\s*(.*)$`)
+	reLink       = regexp.MustCompile(`\[([^\]]+)\]\(([^)]+)\)`)
+	reBoldStar   = regexp.MustCompile(`\*\*(.+?)\*\*`)
+	reBoldUnder  = regexp.MustCompile(`__(.+?)__`)
+	reItalic     = regexp.MustCompile(`_([^_]+)_`)
+	reStrike     = regexp.MustCompile(`~~(.+?)~~`)
+	reListItem   = regexp.MustCompile(`^[-*]\s+`)
+	reCodeBlock  = regexp.MustCompile("```[\\w]*\\n?([\\s\\S]*?)```")
+	reInlineCode = regexp.MustCompile("`([^`]+)`")
+)
+
 type TelegramChannel struct {
 	*BaseChannel
 	bot          *telego.Bot
@@ -431,19 +444,18 @@ func markdownToTelegramHTML(text string) string {
 	inlineCodes := extractInlineCodes(text)
 	text = inlineCodes.text
 
-	text = regexp.MustCompile(`^#{1,6}\s+(.+)$`).ReplaceAllString(text, "$1")
+	text = reHeading.ReplaceAllString(text, "$1")
 
-	text = regexp.MustCompile(`^>\s*(.*)$`).ReplaceAllString(text, "$1")
+	text = reBlockquote.ReplaceAllString(text, "$1")
 
 	text = escapeHTML(text)
 
-	text = regexp.MustCompile(`\[([^\]]+)\]\(([^)]+)\)`).ReplaceAllString(text, `<a href="$2">$1</a>`)
+	text = reLink.ReplaceAllString(text, `<a href="$2">$1</a>`)
 
-	text = regexp.MustCompile(`\*\*(.+?)\*\*`).ReplaceAllString(text, "<b>$1</b>")
+	text = reBoldStar.ReplaceAllString(text, "<b>$1</b>")
 
-	text = regexp.MustCompile(`__(.+?)__`).ReplaceAllString(text, "<b>$1</b>")
+	text = reBoldUnder.ReplaceAllString(text, "<b>$1</b>")
 
-	reItalic := regexp.MustCompile(`_([^_]+)_`)
 	text = reItalic.ReplaceAllStringFunc(text, func(s string) string {
 		match := reItalic.FindStringSubmatch(s)
 		if len(match) < 2 {
@@ -452,9 +464,9 @@ func markdownToTelegramHTML(text string) string {
 		return "<i>" + match[1] + "</i>"
 	})
 
-	text = regexp.MustCompile(`~~(.+?)~~`).ReplaceAllString(text, "<s>$1</s>")
+	text = reStrike.ReplaceAllString(text, "<s>$1</s>")
 
-	text = regexp.MustCompile(`^[-*]\s+`).ReplaceAllString(text, "• ")
+	text = reListItem.ReplaceAllString(text, "• ")
 
 	for i, code := range inlineCodes.codes {
 		escaped := escapeHTML(code)
@@ -479,8 +491,7 @@ type codeBlockMatch struct {
 }
 
 func extractCodeBlocks(text string) codeBlockMatch {
-	re := regexp.MustCompile("```[\\w]*\\n?([\\s\\S]*?)```")
-	matches := re.FindAllStringSubmatch(text, -1)
+	matches := reCodeBlock.FindAllStringSubmatch(text, -1)
 
 	codes := make([]string, 0, len(matches))
 	for _, match := range matches {
@@ -488,7 +499,7 @@ func extractCodeBlocks(text string) codeBlockMatch {
 	}
 
 	i := 0
-	text = re.ReplaceAllStringFunc(text, func(m string) string {
+	text = reCodeBlock.ReplaceAllStringFunc(text, func(m string) string {
 		placeholder := fmt.Sprintf("\x00CB%d\x00", i)
 		i++
 		return placeholder
@@ -503,8 +514,7 @@ type inlineCodeMatch struct {
 }
 
 func extractInlineCodes(text string) inlineCodeMatch {
-	re := regexp.MustCompile("`([^`]+)`")
-	matches := re.FindAllStringSubmatch(text, -1)
+	matches := reInlineCode.FindAllStringSubmatch(text, -1)
 
 	codes := make([]string, 0, len(matches))
 	for _, match := range matches {
@@ -512,7 +522,7 @@ func extractInlineCodes(text string) inlineCodeMatch {
 	}
 
 	i := 0
-	text = re.ReplaceAllStringFunc(text, func(m string) string {
+	text = reInlineCode.ReplaceAllStringFunc(text, func(m string) string {
 		placeholder := fmt.Sprintf("\x00IC%d\x00", i)
 		i++
 		return placeholder

pkg/skills/loader.go

@@ -13,7 +13,11 @@ import (
 	"github.com/sipeed/picoclaw/pkg/logger"
 )
 
-var namePattern = regexp.MustCompile(`^[a-zA-Z0-9]+(-[a-zA-Z0-9]+)*$`)
+var (
+	namePattern        = regexp.MustCompile(`^[a-zA-Z0-9]+(-[a-zA-Z0-9]+)*$`)
+	reFrontmatter      = regexp.MustCompile(`(?s)^---(?:\r\n|\n|\r)(.*?)(?:\r\n|\n|\r)---`)
+	reStripFrontmatter = regexp.MustCompile(`(?s)^---(?:\r\n|\n|\r)(.*?)(?:\r\n|\n|\r)---(?:\r\n|\n|\r)*`)
+)
 
 const (
 	MaxNameLength        = 64
@@ -257,10 +261,7 @@ func (sl *SkillsLoader) parseSimpleYAML(content string) map[string]string {
 
 func (sl *SkillsLoader) extractFrontmatter(content string) string {
 	// Support \n (Unix), \r\n (Windows), and \r (classic Mac) line endings for frontmatter blocks
-	// (?s) enables DOTALL so . matches newlines;
-	// ^--- at start, then ... --- at start of line, honoring all three line ending types
-	re := regexp.MustCompile(`(?s)^---(?:\r\n|\n|\r)(.*?)(?:\r\n|\n|\r)---`)
-	match := re.FindStringSubmatch(content)
+	match := reFrontmatter.FindStringSubmatch(content)
 	if len(match) > 1 {
 		return match[1]
 	}
@@ -268,12 +269,7 @@ func (sl *SkillsLoader) extractFrontmatter(content string) string {
 }
 
 func (sl *SkillsLoader) stripFrontmatter(content string) string {
-	// Support \n (Unix), \r\n (Windows), and \r (classic Mac) line endings for frontmatter blocks
-	// (?s) enables DOTALL so . matches newlines;
-	// ^--- at start, then ... --- at start of line, honoring all three line ending types
-	// Match zero or more trailing line endings after closing --- (handles both with and without blank lines)
-	re := regexp.MustCompile(`(?s)^---(?:\r\n|\n|\r)(.*?)(?:\r\n|\n|\r)---(?:\r\n|\n|\r)*`)
-	return re.ReplaceAllString(content, "")
+	return reStripFrontmatter.ReplaceAllString(content, "")
 }
 
 func escapeXML(s string) string {

pkg/tools/web.go

@@ -17,6 +17,19 @@ const (
 	userAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36"
 )
 
+// Pre-compiled regexes for HTML text extraction
+var (
+	reScript     = regexp.MustCompile(`<script[\s\S]*?</script>`)
+	reStyle      = regexp.MustCompile(`<style[\s\S]*?</style>`)
+	reTags       = regexp.MustCompile(`<[^>]+>`)
+	reWhitespace = regexp.MustCompile(`[^\S\n]+`)
+	reBlankLines = regexp.MustCompile(`\n{3,}`)
+
+	// DuckDuckGo result extraction
+	reDDGLink    = regexp.MustCompile(`<a[^>]*class="[^"]*result__a[^"]*"[^>]*href="([^"]+)"[^>]*>([\s\S]*?)</a>`)
+	reDDGSnippet = regexp.MustCompile(`<a class="result__snippet[^"]*".*?>([\s\S]*?)</a>`)
+)
+
 // createHTTPClient creates an HTTP client with optional proxy support
 func createHTTPClient(proxyURL string, timeout time.Duration) (*http.Client, error) {
 	client := &http.Client{
@@ -251,8 +264,7 @@ func (p *DuckDuckGoSearchProvider) extractResults(html string, count int, query
 	// Try finding the result links directly first, as they are the most critical
 	// Pattern: <a class="result__a" href="...">Title</a>
 	// The previous regex was a bit strict. Let's make it more flexible for attributes order/content
-	reLink := regexp.MustCompile(`<a[^>]*class="[^"]*result__a[^"]*"[^>]*href="([^"]+)"[^>]*>([\s\S]*?)</a>`)
-	matches := reLink.FindAllStringSubmatch(html, count+5)
+	matches := reDDGLink.FindAllStringSubmatch(html, count+5)
 
 	if len(matches) == 0 {
 		return fmt.Sprintf("No results found or extraction failed. Query: %s", query), nil
@@ -269,8 +281,7 @@ func (p *DuckDuckGoSearchProvider) extractResults(html string, count int, query
 
 	// A better regex approach: iterate through text and find matches in order
 	// But for now, let's grab all snippets too
-	reSnippet := regexp.MustCompile(`<a class="result__snippet[^"]*".*?>([\s\S]*?)</a>`)
-	snippetMatches := reSnippet.FindAllStringSubmatch(html, count+5)
+	snippetMatches := reDDGSnippet.FindAllStringSubmatch(html, count+5)
 
 	maxItems := min(len(matches), count)
 
@@ -305,8 +316,7 @@ func (p *DuckDuckGoSearchProvider) extractResults(html string, count int, query
 }
 
 func stripTags(content string) string {
-	re := regexp.MustCompile(`<[^>]+>`)
-	return re.ReplaceAllString(content, "")
+	return reTags.ReplaceAllString(content, "")
 }
 
 type PerplexitySearchProvider struct {
@@ -654,19 +664,14 @@ func (t *WebFetchTool) Execute(ctx context.Context, args map[string]any) *ToolRe
 }
 
 func (t *WebFetchTool) extractText(htmlContent string) string {
-	re := regexp.MustCompile(`<script[\s\S]*?</script>`)
-	result := re.ReplaceAllLiteralString(htmlContent, "")
-	re = regexp.MustCompile(`<style[\s\S]*?</style>`)
-	result = re.ReplaceAllLiteralString(result, "")
-	re = regexp.MustCompile(`<[^>]+>`)
-	result = re.ReplaceAllLiteralString(result, "")
+	result := reScript.ReplaceAllLiteralString(htmlContent, "")
+	result = reStyle.ReplaceAllLiteralString(result, "")
+	result = reTags.ReplaceAllLiteralString(result, "")
 
 	result = strings.TrimSpace(result)
 
-	re = regexp.MustCompile(`[^\S\n]+`)
-	result = re.ReplaceAllString(result, " ")
-	re = regexp.MustCompile(`\n{3,}`)
-	result = re.ReplaceAllString(result, "\n\n")
+	result = reWhitespace.ReplaceAllString(result, " ")
+	result = reBlankLines.ReplaceAllString(result, "\n\n")
 
 	lines := strings.Split(result, "\n")
 	var cleanLines []string