Implement runfile and support for .str.rc

HELP.md

@@ -358,3 +358,7 @@ str %> call $myFooReplacer bar
 Replace the current subject with "Lorem ipsum..." placeholder text.
 Can generate individual words, lines, or paragraphs.
 Example: `lipsum 4 word` -> `lorem ipsum dolor sit`
+
+#### User-specific setup files
+The file `~/.str.rc` is automatically executed when `str` starts up.
+You can use this to define a user-specific environment.

src/index.ts

@@ -6,27 +6,39 @@ import {Parser} from "./vm/parser.js";
 import {commands} from "./vm/commands/index.js";
 import {Executor} from "./vm/vm.js";
 import {ConsoleDisplay, OutputManager, WlClipboard} from "./vm/output.js";
+import {processPath} from "./vm/commands/command.js";
+import * as fs from "node:fs";
 
-const lifecycle = new Lifecycle()
-const input = new Input()
-input.adoptLifecycle(lifecycle)
-input.subscribe(line => log.verbose('input', { line }))
+;(async () => {
+	const lifecycle = new Lifecycle()
+	const input = new Input()
+	input.adoptLifecycle(lifecycle)
+	input.subscribe(line => log.verbose('input', { line }))
 
-const lexer = new Lexer(input)
-lexer.subscribe(token => log.verbose('token', token))
+	const lexer = new Lexer(input)
+	lexer.subscribe(token => log.verbose('token', token))
 
-const parser = new Parser(commands, lexer)
-parser.subscribe(exec => log.verbose('exec', exec))
+	const parser = new Parser(commands, lexer)
+	parser.subscribe(exec => log.verbose('exec', exec))
 
-const output: OutputManager = {
-    display: new ConsoleDisplay,
-    clipboard: new WlClipboard,
-}
+	const output: OutputManager = {
+		display: new ConsoleDisplay,
+		clipboard: new WlClipboard,
+	}
 
-const exec = new Executor(output, parser, input)
-exec.adoptLifecycle(lifecycle)
-exec.subscribe(state => state.outputSubject())
+	const exec = new Executor(output, parser, input)
+	exec.adoptLifecycle(lifecycle)
+	exec.subscribe(state => state.outputSubject())
 
-input.setupPrompt()
+	const rcFile = processPath('~/.str.rc')
+	if ( fs.existsSync(rcFile) ) {
+		log.verbose('rc', { rcFile })
 
-process.on('SIGINT', () => lifecycle.close())
+		const rcFileContent = fs.readFileSync(rcFile).toString()
+		await input.pushLines('\n' + rcFileContent)
+	}
+
+	input.setupPrompt()
+
+	process.on('SIGINT', () => lifecycle.close())
+})()

src/vm/commands/runfile.ts

@@ -1,5 +1,6 @@
 import {Command, ParseContext, StrTerm} from "./command.js";
 import {LexInput} from "../lexer.js";
+import {StrVM} from "../vm.js";
 
 export class RunFile extends Command<{ path: StrTerm }> {
     isParseCandidate(token: LexInput): boolean {
@@ -13,4 +14,12 @@ export class RunFile extends Command<{ path: StrTerm }> {
     getDisplayName(): string {
         return 'runfile'
     }
+
+    execute(vm: StrVM, data: { path: StrTerm }): Promise<StrVM> {
+        return vm.tapInPlace(async ctx => {
+            await vm.control$.next({ cmd: 'preserve-history' })
+            const path = ctx.resolveString(data.path)
+            await vm.control$.next({ cmd: 'lex-file', path })
+        })
+    }
 }

src/vm/input.ts

@@ -10,6 +10,12 @@ export class Input extends BehaviorSubject<string> implements LifecycleAware {
 
 	public readonly errors$: BehaviorSubject<Error> = new BehaviorSubject()
 
+	public async pushLines(str: string): Promise<void> {
+		for ( const line of str.split('\n') ) {
+			await this.next(line + '\n')
+		}
+	}
+
 	public hasPrompt(): boolean {
 		return !!this.rl
 	}

src/vm/vm.ts

@@ -1,7 +1,7 @@
 import {Awaitable, hasOwnProperty, JSONData} from "../util/types.js";
 import {
     CommandData, destructureToLines, isStrLVal,
-    isStrRVal, joinDestructured, StrDestructured, StrLamba,
+    isStrRVal, joinDestructured, processPath, StrDestructured, StrLamba,
     StrLVal,
     StrRVal,
     StrTerm, TypeError, unwrapDestructured,
@@ -17,6 +17,7 @@ import {Executable} from "./parse.js";
 import {getSubjectDisplay, OutputManager} from "./output.js";
 import {Input} from "./input.js";
 import {Lifecycle, LifecycleAware} from "../util/lifecycle.js";
+import * as fs from "node:fs/promises";
 
 export class Scope {
     private entries: Record<string, StrRVal> = {}
@@ -361,6 +362,7 @@ export class ExecutionContext {
 
 export type Control =
     { cmd: 'undo' | 'redo' | 'exit' | 'no-show' | 'preserve-history' | 'close-prompt' | 'restore-prompt' }
+    | { cmd: 'lex-file', path: string }
 
 export class StrVM implements LifecycleAware {
     public static make(output: OutputManager, input?: Input): StrVM {
@@ -415,6 +417,15 @@ export class StrVM implements LifecycleAware {
             this.wasPromptWhenClosed = false
         } else if ( control.cmd === 'exit' ) {
             this.lifecycle?.close()
+        } else if ( control.cmd === 'lex-file' ) {
+            const path = processPath(control.path)
+            const content = (await fs.readFile(path)).toString()
+
+            // Since control commands happen WITHIN the current promise chain,
+            // the parser stage in the pipeline may still think the current parse
+            // operation is in-progress. So, include an initial TERMINATOR to ensure
+            // the file parses starting as a new statement.
+            await this.input?.pushLines('\n' + content)
         }
     }