Files
str/src/vm/commands/load.ts

41 lines
1.3 KiB
TypeScript

import {Command, ParseContext, processPath, StrTerm} from "./command.js";
import {LexInput} from "../lexer.js";
import {StrVM} from "../vm.js";
import {Awaitable} from "../../util/types.js";
import os from "node:os";
import fs from "node:fs/promises";
import {isSaveData} from "./save.js";
export class Load extends Command<{ path?: StrTerm }> {
isParseCandidate(token: LexInput): boolean {
return this.isKeyword(token, 'load')
}
async attemptParse(context: ParseContext): Promise<{ path?: StrTerm }> {
return { path: await context.popOptionalTerm() }
}
getDisplayName(): string {
return 'load'
}
execute(vm: StrVM, data: { path?: StrTerm }): Awaitable<StrVM> {
return vm.replaceContextMatchingTerm(ctx => ({
override: async () => {
const path = processPath(
data.path
? ctx.resolveString(data.path)
: `~/.str.json`)
const content = await fs.readFile(path, 'utf8')
const saveData = JSON.parse(content)
if ( !isSaveData(saveData) ) {
throw new Error('Cannot load: invalid save data')
}
return saveData.subject
}
}))
}
}