Implement output/clipboard interfaces, stub implementations, and implement execute()s for Copy and Paste

src/index.ts

@@ -5,6 +5,7 @@ import {Lexer} from "./vm/lexer.js";
 import {Parser} from "./vm/parser.js";
 import {commands} from "./vm/commands/index.js";
 import {Executor} from "./vm/vm.js";
+import {ConsoleDisplay, FakeClipboard, OutputManager} from "./vm/output.js";
 
 const lifecycle = new Lifecycle()
 const input = new Input()
@@ -17,8 +18,13 @@ lexer.subscribe(token => log.verbose('token', token))
 const parser = new Parser(commands, lexer)
 parser.subscribe(exec => log.verbose('exec', exec))
 
-const exec = new Executor(parser)
-exec.subscribe(state => state.output())
+const output: OutputManager = {
+    display: new ConsoleDisplay,
+    clipboard: new FakeClipboard,
+}
+
+const exec = new Executor(output, parser)
+exec.subscribe(state => state.outputSubject())
 
 input.setupPrompt()
 

src/vm/commands/copy.ts

@@ -1,5 +1,7 @@
-import {Command, ParseContext} from "./command.js";
+import {Command, ParseContext, unwrapString} from "./command.js";
 import {LexInput} from "../lexer.js";
+import {StrVM} from "../vm.js";
+import {Awaitable} from "../../util/types.js";
 
 export class Copy extends Command<{}> {
     isParseCandidate(token: LexInput): boolean {
@@ -13,4 +15,10 @@ export class Copy extends Command<{}> {
     getDisplayName(): string {
         return 'copy'
     }
+
+    execute(vm: StrVM): Awaitable<StrVM> {
+        return vm.tapInPlace(ctx =>
+            vm.withOutput(output =>
+                output.clipboard.overwrite(unwrapString(ctx.getSubject()))))
+    }
 }

src/vm/commands/paste.ts

@@ -1,5 +1,7 @@
-import {Command, ParseContext} from "./command.js";
+import {Command, ParseContext, wrapString} from "./command.js";
 import {LexInput} from "../lexer.js";
+import {StrVM} from "../vm.js";
+import {Awaitable} from "../../util/types.js";
 
 export class Paste extends Command<{}> {
     isParseCandidate(token: LexInput): boolean {
@@ -13,4 +15,12 @@ export class Paste extends Command<{}> {
     getDisplayName(): string {
         return 'paste'
     }
+
+    execute(vm: StrVM): Awaitable<StrVM> {
+        return vm.replaceContextMatchingTerm({
+            override: () =>
+                vm.withOutput(async output =>
+                    wrapString(await output.clipboard.read()))
+        })
+    }
 }

src/vm/output.ts

@@ -1,4 +1,5 @@
 import {StrRVal} from "./commands/command.js";
+import {Awaitable} from "../util/types.js";
 
 export const getSubjectDisplay = (sub: StrRVal): string => {
     if ( sub.term === 'string' ) {
@@ -11,3 +12,39 @@ export const getSubjectDisplay = (sub: StrRVal): string => {
 
     return JSON.stringify(sub.value, null, '\t')  // fixme
 }
+
+export type Display = {
+    showSubject(sub: StrRVal): Awaitable<unknown>
+}
+
+export class ConsoleDisplay implements Display {
+    showSubject(sub: StrRVal) {
+        console.log(`\n---------------\n${getSubjectDisplay(sub)}\n---------------\n`)
+    }
+}
+
+export class NullDisplay implements Display {
+    showSubject() {}
+}
+
+export type Clipboard = {
+    read(): Awaitable<string>
+    overwrite(sub: string): Awaitable<unknown>
+}
+
+export class FakeClipboard {
+    private val = ''
+
+    read() {
+        return this.val
+    }
+
+    overwrite(sub: string) {
+        this.val = sub
+    }
+}
+
+export type OutputManager = {
+    display: Display,
+    clipboard: Clipboard,
+}

src/vm/vm.ts

@@ -14,7 +14,7 @@ import {StreamLogger} from "../util/log.js";
 import {Parser} from "./parser.js";
 import {log} from "../log.js";
 import {Executable} from "./parse.js";
-import {getSubjectDisplay} from "./output.js";
+import {getSubjectDisplay, OutputManager} from "./output.js";
 
 export class Scope {
     private entries: Record<string, StrRVal> = {}
@@ -188,13 +188,16 @@ export class ExecutionContext {
 }
 
 export class StrVM {
-    public static make(): StrVM {
+    public static make(output: OutputManager): StrVM {
         return new StrVM(
-            new ExecutionContext(wrapString(''), new Scope()))
+            new ExecutionContext(wrapString(''), new Scope()),
+            output,
+        )
     }
 
     constructor(
         private context: ExecutionContext,
+        private output: OutputManager,
     ) {}
 
     public async runInPlace<TReturn>(operator: (ctx: ExecutionContext) => Awaitable<TReturn>): Promise<TReturn> {
@@ -230,28 +233,30 @@ export class StrVM {
                 })))
     }
 
-    output() {
-        console.log('---------------')
-        console.log(getSubjectDisplay(this.context.getSubject()))
-        console.log('---------------')
+    public async withOutput<TReturn>(operator: (output: OutputManager) => Awaitable<TReturn>): Promise<TReturn> {
+        return operator(this.output)
     }
 
     makeChild(): StrVM {
-        return new StrVM(this.context.makeChild())
+        return new StrVM(this.context.makeChild(), this.output)
+    }
+
+    async outputSubject(): Promise<void> {
+        await this.output.display.showSubject(this.context.getSubject())
     }
 }
 
 export class Executor extends BehaviorSubject<StrVM> {
     private logger: StreamLogger
 
-    constructor(parser?: Parser) {
+    constructor(private output: OutputManager, parser?: Parser) {
         super()
         this.logger = log.getStreamLogger('executor')
         parser?.subscribe(exec  => this.handleExecutable(exec))
     }
 
     async handleExecutable(exec: Executable<CommandData>) {
-        const vm = this.currentValue || StrVM.make()
+        const vm = this.currentValue || StrVM.make(this.output)
         await this.next(await exec.command.execute(vm, exec.data))
     }
 }