shell.ts

import { run } from './index'
const prompt = require('prompt-sync')()

while (true) {
	let textInput = prompt('REPL > ')
	let [result, error] = run('<stdin>', textInput)

	if (error) {
		console.log(error.asString())
	} else if (result !== null && result !== undefined) {
		if (
			result.constructor &&
			result.constructor.name === 'ListValue' &&
			Array.isArray(result.elements)
		) {
			const filtered = result.elements.filter(
				(e: any) =>
					e !== null &&
					e !== undefined &&
					!(
						typeof e.asString === 'function' &&
						(e.asString() === '' || e.asString() === '[]')
					)
			)
			// Heuristic: if input is a single line and starts with '[', treat as list literal
			if (textInput.trim().startsWith('[')) {
				console.log(
					'[' +
						filtered
							.map((e: any) =>
								typeof e.asString === 'function'
									? e.asString()
									: String(e)
							)
							.join(', ') +
						']'
				)
			} else if (filtered.length > 0) {
				const last = filtered[filtered.length - 1]
				// If the last statement is a print statement, don't print its value again
				const lines = textInput.trim().split(/\r?\n/).filter((l: string) => l.trim() !== '')
				const lastLine = lines[lines.length - 1].trim()
				if (!/^print\s*\(/.test(lastLine)) {
					if (last && typeof last.asString === 'function') {
						console.log(last.asString())
					} else {
						console.log(last)
					}
				}
			}
			// If filtered.length === 0, print nothing
		} else if (
			typeof result.asString === 'function' &&
			result.asString() !== '' &&
			result.asString() !== '[]'
		) {
			const lines = textInput.trim().split(/\r?\n/).filter((l: string) => l.trim() !== '')
			const lastLine = lines[lines.length - 1].trim()
			if (!/^print\s*\(/.test(lastLine)) {
				console.log(result.asString())
			}
		}
	}
}