WebAssembly does not support multi-file programs

[ianyong]

Because Sourceror is not part of js-slang, the pre-processing step which handles imports & exports does not work with Sourceror. This means that the WebAssembly variants of Source do not support multi-file programs currently. Instead, only the entrypoint file is passed to Sourceror currently:

frontend/src/commons/sagas/WorkspaceSaga.ts

Lines 1035 to 1060 in f2b05b2

	const entrypointCode = files[entrypointFilePath];
	function call_variant(variant: Variant) {
	if (variant === Variant.NON_DET) {
	return entrypointCode.trim() === TRY_AGAIN
	? call(resume, lastNonDetResult)
	: call(runFilesInContext, files, entrypointFilePath, context, {
	executionMethod: 'interpreter',
	originalMaxExecTime: execTime,
	stepLimit: stepLimit,
	useSubst: substActiveAndCorrectChapter
	});
	} else if (variant === Variant.LAZY) {
	return call(runFilesInContext, files, entrypointFilePath, context, {
	scheduler: 'preemptive',
	originalMaxExecTime: execTime,
	stepLimit: stepLimit,
	useSubst: substActiveAndCorrectChapter
	});
	} else if (variant === Variant.WASM) {
	// Note: WASM does not support multiple file programs.
	return call(wasm_compile_and_run, entrypointCode, context, actionType === EVAL_REPL);
	} else {
	throw new Error('Unknown variant: ' + variant);
	}
	}

[martin-henz]

"Source WebAssembly" has always been a kind of "proof of concept". There will be various efforts to integrate WebAssembly-based implementations in the next year. I feel that we can retire "Source WebAssembly" if it causes maintenance issues. @btzy any views on this?

[btzy]

If there's nobody around who is able and willing to maintain Sourceror then it would have to be retired at some point. Also because there's virtually nobody using it, there isn't really much motivation for anyone to keep it up to date. Are the "efforts to integrate WebAssembly-based implementations" actually going to bring something better?

[martin-henz]

Are the "efforts to integrate WebAssembly-based implementations" actually going to bring something better?

Yes, I hope so. Check out this module to start:

source-academy/modules#204

We'll start using this for compiler work next semester.