landed the dictionary objects and spelling rewriter, which also allowed me to complete the configuration YAML file

htmlcheck/dictionary.go

@@ -9,15 +9,86 @@
 // The htmlcheck package contains the HTML Checker.
 package htmlcheck
 
+import (
+	_ "embed"
+	"os"
+
+	"git.erbosoft.com/amy/amsterdam/config"
+	log "github.com/sirupsen/logrus"
+)
+
+// SpellingDictionary is a simple dictionary interface.
 type SpellingDictionary interface {
 	Ready() bool
 	Size() int
 	CheckWord(string) bool
 }
 
+// ModSpellingDictionary is an intrerface to a modifiable spelling dictionary.
 type ModSpellingDictionary interface {
 	SpellingDictionary
 	AddWord(string)
 	DelWord(string)
 	Clear()
 }
+
+//go:embed en-us.dict
+var mainDict []byte
+
+//go:embed supplement.dict
+var supplementaryDict []byte
+
+// SetupDicts sets up the dictionaries and the spelling rewriter.
+func SetupDicts() {
+	dicts := make([]SpellingDictionary, 2, 3)
+	dicts[0] = LoadTrieDict(mainDict)
+	dicts[1] = LoadTrieDict(supplementaryDict)
+	if config.GlobalConfig.Posting.ExternalDictionary != "" {
+		data, err := os.ReadFile(config.GlobalConfig.Posting.ExternalDictionary)
+		if err == nil {
+			ndict := LoadTrieDict(data)
+			dicts = append(dicts, ndict)
+		} else {
+			log.Errorf("failed to load external dictionary %s: %v", config.GlobalConfig.Posting.ExternalDictionary, err)
+		}
+	}
+	rw := spellingRewriter{
+		dict: NewCompositeDict(dicts),
+	}
+	rewriterRegistry[rw.Name()] = &rw
+}
+
+// spellingRewriter is a rewriter that flags spelling errors.
+type spellingRewriter struct {
+	dict SpellingDictionary
+}
+
+// defaultBeginError is the markup that indicates the start of an error.
+const defaultBeginError = "<span class=\"text-red-600 font-bold\">"
+
+// defaultEndError is the markup that indicates the end of an error.
+const defaultEndError = "</span>"
+
+// Name returns the rewriter's name.
+func (rw *spellingRewriter) Name() string {
+	return "spelling"
+}
+
+/* Rewrite rewrites the given string data and adds markup before and after if needed.
+ * Parameters:
+ *     data - The data to be rewritten.
+ *     svc - Services interface we can use.
+ * Returns:
+ *     Pointer to markup data, or nil.
+ */
+func (rw *spellingRewriter) Rewrite(data string, svc rewriterServices) *markupData {
+	if rw.dict.CheckWord(data) {
+		return nil
+	}
+	return &markupData{
+		beginMarkup: defaultBeginError,
+		text:        data,
+		endMarkup:   defaultEndError,
+		rescan:      false,
+	}
+}