2 files changed, 49 insertions, 6 deletions
diff --git a/types/ext/language-descriptors.d.ts b/types/ext/language-descriptors.d.ts
index 00a95883..319a3ca5 100644
--- a/types/ext/language-descriptors.d.ts
+++ b/types/ext/language-descriptors.d.ts
@@ -15,7 +15,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-import type {TextPreprocessor} from './language';
+import type {TextPreprocessor, BidirectionalConversionPreprocessor} from './language';
 import type {SafeAny} from './core';
 
 type LanguageDescriptor<TIso extends string, TTextPreprocessorDescriptor extends TextPreprocessorDescriptor> = {
@@ -35,21 +35,55 @@ type LanguageDescriptorObjectMap = {
 
 export type LanguageDescriptorAny = LanguageDescriptorObjectMap[keyof LanguageDescriptorObjectMap];
 
+type CapitalizationPreprocessors = {
+    capitalizeFirstLetter: TextPreprocessor<boolean>;
+    decapitalize: TextPreprocessor<boolean>;
+};
+
 /**
  * This is a mapping of the iso tag to all of the preprocessors for that language.
  * Any new language should be added to this object.
  */
 type AllTextPreprocessors = {
-    en: {
-        capitalizeFirstLetter: TextPreprocessor<boolean>;
-        decapitalize: TextPreprocessor<boolean>;
+    ar: {
+        removeArabicScriptDiacritics: TextPreprocessor<boolean>;
+    };
+    de: CapitalizationPreprocessors & {
+        eszettPreprocessor: BidirectionalConversionPreprocessor;
+    };
+    el: CapitalizationPreprocessors;
+    en: CapitalizationPreprocessors;
+    es: CapitalizationPreprocessors;
+    fa: {
+        removeArabicScriptDiacritics: TextPreprocessor<boolean>;
+    };
+    fr: CapitalizationPreprocessors;
+    grc: CapitalizationPreprocessors;
+    hu: CapitalizationPreprocessors;
+    id: CapitalizationPreprocessors;
+    it: CapitalizationPreprocessors;
+    la: {
+        removeLatinDiacritics: TextPreprocessor<boolean>;
     };
     ja: {
         convertHalfWidthCharacters: TextPreprocessor<boolean>;
         convertNumericCharacters: TextPreprocessor<boolean>;
         convertAlphabeticCharacters: TextPreprocessor<boolean>;
-        convertHiraganaToKatakana: TextPreprocessor<boolean>;
-        convertKatakanaToHiragana: TextPreprocessor<boolean>;
+        convertHiraganaToKatakana: BidirectionalConversionPreprocessor;
         collapseEmphaticSequences: TextPreprocessor<[collapseEmphatic: boolean, collapseEmphaticFull: boolean]>;
     };
+    km: Record<string, never>;
+    pl: CapitalizationPreprocessors;
+    pt: CapitalizationPreprocessors;
+    ro: CapitalizationPreprocessors;
+    ru: CapitalizationPreprocessors & {
+        yoToE: TextPreprocessor<boolean>;
+        removeRussianDiacritics: TextPreprocessor<boolean>;
+    };
+    sh: CapitalizationPreprocessors;
+    sq: CapitalizationPreprocessors;
+    sv: CapitalizationPreprocessors;
+    th: Record<string, never>;
+    vi: CapitalizationPreprocessors;
+    zh: Record<string, never>;
 };
diff --git a/types/ext/language.d.ts b/types/ext/language.d.ts
index efbb16c6..8e5a5c70 100644
--- a/types/ext/language.d.ts
+++ b/types/ext/language.d.ts
@@ -21,6 +21,11 @@ export type TextPreprocessorOptions<T = unknown> = T[];
 
 export type TextPreprocessorFunction<T = unknown> = (str: string, setting: T, sourceMap: TextSourceMap) => string;
 
+/**
+ * Text preprocessors are used during the translation process to create alternate versions of the input text to search for.
+ * This is helpful when the input text doesn't exactly match the term or expression found in the database.
+ * When a language has multiple preprocessors, the translator will generate variants of the text by applying all combinations of the preprocessors.
+ */
 export type TextPreprocessor<T = unknown> = {
     name: string;
     description: string;
@@ -28,6 +33,10 @@ export type TextPreprocessor<T = unknown> = {
     process: TextPreprocessorFunction<T>;
 };
 
+export type BidirectionalPreprocessorOptions = 'off' | 'direct' | 'inverse';
+
+export type BidirectionalConversionPreprocessor = TextPreprocessor<BidirectionalPreprocessorOptions>;
+
 export type LanguageAndPreprocessors = {
     iso: string;
     textPreprocessors: TextPreprocessorWithId<unknown>[];