use nullable value instead

Author: neverRare

src/translator/ast.ts

@@ -53,7 +53,7 @@ export type Adverb = Readonly<{
 export type AdverbVerb = {
   preAdverb: ReadonlyArray<Adverb>;
   verb: Word;
-  postAdverb: ReadonlyArray<Adverb>;
+  postAdverb: null | Adverb;
 };
 export type Verb = Readonly<{
   modal: null | AdverbVerb;

src/translator/composer.ts

@@ -76,7 +76,7 @@ function adverbVerb(verbAdverb: English.AdverbVerb) {
   return [
     ...preAdverb.map(({ adverb }) => adverb),
     verb,
-    ...postAdverb.map(({ adverb }) => adverb),
+    ...nullableAsArray(postAdverb).map(({ adverb }) => adverb),
   ]
     .map(word).join(" ");
 }

src/translator/phrase.ts

@@ -174,7 +174,7 @@ function verbPhrase(
       preposition,
     };
   } else if (verb.modal != null) {
-    const postAdverb = negated ? [NOT] : [];
+    const postAdverb = negated ? NOT : null;
     return {
       ...verb,
       modal: {

src/translator/verb.ts

@@ -68,12 +68,12 @@ function addModal(
         return {
           preAdverb,
           verb: word({ ...first, word: useVerb }),
-          postAdverb: [],
+          postAdverb: null,
         };
       });
     const postAdverb = takeNegative && (verb.first?.negated ?? false)
-      ? [NOT]
-      : [];
+      ? NOT
+      : null;
     return {
       ...verb,
       modal: {
@@ -224,7 +224,7 @@ function fromVerbForms(
             doesNot: {
               preAdverb: [],
               verb: noEmphasis(`${does} not/did not/will not`),
-              postAdverb: [],
+              postAdverb: null,
             },
             verb: verbForms.presentPlural,
             postAdverb: null,
@@ -258,7 +258,7 @@ function fromVerbForms(
               modal: {
                 preAdverb: [],
                 verb: noEmphasis("will"),
-                postAdverb: [NOT],
+                postAdverb: NOT,
               },
               verb: "be",
               postAdverb: null,
@@ -272,22 +272,22 @@ function fromVerbForms(
               doesNot: {
                 preAdverb: [],
                 verb: noEmphasis(does),
-                postAdverb: [NOT],
+                postAdverb: NOT,
               },
             },
             {
               modal: null,
               doesNot: {
                 preAdverb: [],
                 verb: noEmphasis("did"),
-                postAdverb: [NOT],
+                postAdverb: NOT,
               },
             },
             {
               modal: {
                 preAdverb: [],
                 verb: noEmphasis("will"),
-                postAdverb: [NOT],
+                postAdverb: NOT,
               },
               doesNot: null,
             },
@@ -327,7 +327,7 @@ function fromVerbForms(
             doesNot: {
               preAdverb: [],
               verb: noEmphasis(does),
-              postAdverb: [NOT],
+              postAdverb: NOT,
             },
             verb: verbForms.presentPlural,
             postAdverb: null,
@@ -350,7 +350,7 @@ function fromVerbForms(
       {
         preAdverb: adverb,
         verb: word({ ...verbForms, word: verb }),
-        postAdverb: nullableAsArray(postAdverb),
+        postAdverb,
       },
     ],
   }));
@@ -403,5 +403,5 @@ export function verb(
   }
 }
 export function noAdverbs(verb: English.Word): English.AdverbVerb {
-  return { preAdverb: [], verb, postAdverb: [] };
+  return { preAdverb: [], verb, postAdverb: null };
 }

src/translator/word_unit.ts

@@ -86,7 +86,7 @@ function defaultWordUnit(
                 reduplicationCount,
                 emphasis: emphasis != null,
               }),
-              postAdverb: [],
+              postAdverb: null,
             },
             first: null,
             rest: [],