docs: Embed docs

.golangci.yml

@@ -138,3 +138,6 @@ issues:
   - linters:
     - goerr113
     text: do not define dynamic errors, use wrapped static errors instead
+  - linters:
+    - gochecknoinits
+    path: "docs/docs.go"

docs/docs.go

@@ -0,0 +1,68 @@
+package docs
+
+import (
+	_ "embed"
+	"regexp"
+	"strings"
+)
+
+//go:embed templatefuncs.md
+var templateFuncsStr string
+
+type Reference struct {
+	Title   string
+	Body    string
+	Example string
+}
+
+var References map[string]Reference
+
+func init() {
+	newlineRx := regexp.MustCompile(`\r?\n`)
+
+	// Template function names must start with a letter or underscore
+	// and can subsequently contain letters, underscores and digits.
+	funcNameRx := regexp.MustCompile("`" + `([a-zA-Z_]\w*)` + "`")
+
+	References = make(map[string]Reference)
+	var reference Reference
+	var funcName string
+	var b strings.Builder
+	var e strings.Builder
+	inExample := false
+
+	for _, line := range newlineRx.Split(templateFuncsStr, -1) {
+		switch {
+		case strings.HasPrefix(line, "## "):
+			if reference.Title != "" {
+				References[funcName] = reference
+			}
+			funcName = funcNameRx.FindStringSubmatch(line)[1]
+			reference = Reference{}
+			reference.Title = strings.TrimPrefix(line, "## ")
+		case strings.HasPrefix(line, "```"):
+			if !inExample {
+				reference.Body = strings.TrimSpace(b.String())
+				b.Reset()
+			}
+			e.WriteString(line + "\n")
+			if inExample {
+				reference.Example = strings.TrimSpace(e.String())
+				e.Reset()
+			}
+			inExample = !inExample
+		case inExample:
+			if _, err := e.WriteString(line + "\n"); err != nil {
+				panic(err)
+			}
+		case reference.Title != "":
+			if _, err := b.WriteString(line + "\n"); err != nil {
+				panic(err)
+			}
+		}
+	}
+
+	if reference.Title != "" {
+		References[funcName] = reference
+	}
+}