Introduce TermOperator helper and refactor execute()s to use replaceSubjectMatchingTerm

src/vm/commands/words.ts

@@ -1,4 +1,4 @@
-import {Command, ParseContext, unwrapString, wrapDestructured} from "./command.js";
+import {Command, ParseContext} from "./command.js";
 import {LexInput} from "../lexer.js";
 import {StrVM} from "../vm.js";
 import {Awaitable} from "../../util/types.js";
@@ -17,17 +17,16 @@ export class Words extends Command<{}> {
     }
 
     execute(vm: StrVM): Awaitable<StrVM> {
-        return vm.tapInPlace(ctx =>
-            ctx.replaceSubject(sub => {
-                const val = unwrapString(sub)
-                const separators = [...val.matchAll(/\s+/sg)]
-                const parts = val.split(/\s+/sg)
+        return vm.replaceContextMatchingTerm({
+            destructure: sub => {
+                const separators = [...sub.matchAll(/\s+/sg)]
+                const parts = sub.split(/\s+/sg)
 
-                return wrapDestructured(
-                    parts.map((part, idx) => ({
-                        prefix: idx ? separators[idx - 1][0] : undefined,
-                        value: part,
-                    })))
-            }))
+                return parts.map((part, idx) => ({
+                    prefix: idx ? separators[idx - 1][0] : undefined,
+                    value: part,
+                }))
+            }
+        })
     }
 }