mirror of
https://github.com/kanaka/mal.git
synced 2024-10-27 14:52:16 +03:00
8a19f60386
- Reorder README to have implementation list after "learning tool" bullet. - This also moves tests/ and libs/ into impls. It would be preferrable to have these directories at the top level. However, this causes difficulties with the wasm implementations which need pre-open directories and have trouble with paths starting with "../../". So in lieu of that, symlink those directories to the top-level. - Move the run_argv_test.sh script into the tests directory for general hygiene.
127 lines
3.5 KiB
Dart
127 lines
3.5 KiB
Dart
import 'dart:io';
|
|
|
|
import 'env.dart';
|
|
import 'printer.dart' as printer;
|
|
import 'reader.dart' as reader;
|
|
import 'types.dart';
|
|
|
|
final Env replEnv = new Env();
|
|
|
|
void setupEnv() {
|
|
replEnv.set(new MalSymbol('+'), new MalBuiltin((List<MalType> args) {
|
|
var a = args[0] as MalInt;
|
|
var b = args[1] as MalInt;
|
|
return new MalInt(a.value + b.value);
|
|
}));
|
|
replEnv.set(new MalSymbol('-'), new MalBuiltin((List<MalType> args) {
|
|
var a = args[0] as MalInt;
|
|
var b = args[1] as MalInt;
|
|
return new MalInt(a.value - b.value);
|
|
}));
|
|
replEnv.set(new MalSymbol('*'), new MalBuiltin((List<MalType> args) {
|
|
var a = args[0] as MalInt;
|
|
var b = args[1] as MalInt;
|
|
return new MalInt(a.value * b.value);
|
|
}));
|
|
replEnv.set(new MalSymbol('/'), new MalBuiltin((List<MalType> args) {
|
|
var a = args[0] as MalInt;
|
|
var b = args[1] as MalInt;
|
|
return new MalInt(a.value ~/ b.value);
|
|
}));
|
|
}
|
|
|
|
MalType READ(String x) => reader.read_str(x);
|
|
|
|
MalType eval_ast(MalType ast, Env env) {
|
|
if (ast is MalSymbol) {
|
|
var result = env.get(ast);
|
|
if (result == null) {
|
|
throw new NotFoundException(ast.value);
|
|
}
|
|
return result;
|
|
} else if (ast is MalList) {
|
|
return new MalList(ast.elements.map((x) => EVAL(x, env)).toList());
|
|
} else if (ast is MalVector) {
|
|
return new MalVector(ast.elements.map((x) => EVAL(x, env)).toList());
|
|
} else if (ast is MalHashMap) {
|
|
var newMap = new Map<MalSymbol, MalType>.from(ast.value);
|
|
for (var key in newMap.keys) {
|
|
newMap[key] = EVAL(newMap[key], env);
|
|
}
|
|
return new MalHashMap(newMap);
|
|
} else {
|
|
return ast;
|
|
}
|
|
}
|
|
|
|
MalType EVAL(MalType ast, Env env) {
|
|
if (ast is! MalList) {
|
|
return eval_ast(ast, env);
|
|
} else {
|
|
if ((ast as MalList).elements.isEmpty) {
|
|
return ast;
|
|
} else {
|
|
var list = ast as MalList;
|
|
if (list.elements.first is MalSymbol) {
|
|
var symbol = list.elements.first as MalSymbol;
|
|
var args = list.elements.sublist(1);
|
|
if (symbol.value == "def!") {
|
|
MalSymbol key = args.first;
|
|
MalType value = EVAL(args[1], env);
|
|
env.set(key, value);
|
|
return value;
|
|
} else if (symbol.value == "let*") {
|
|
// TODO(het): If elements.length is not even, give helpful error
|
|
Iterable<List<MalType>> pairs(List<MalType> elements) sync* {
|
|
for (var i = 0; i < elements.length; i += 2) {
|
|
yield [elements[i], elements[i + 1]];
|
|
}
|
|
}
|
|
|
|
var newEnv = new Env(env);
|
|
MalIterable bindings = args.first;
|
|
for (var pair in pairs(bindings.elements)) {
|
|
MalSymbol key = pair[0];
|
|
MalType value = EVAL(pair[1], newEnv);
|
|
newEnv.set(key, value);
|
|
}
|
|
return EVAL(args[1], newEnv);
|
|
}
|
|
}
|
|
var newAst = eval_ast(ast, env) as MalList;
|
|
MalBuiltin f = newAst.elements.first;
|
|
var args = newAst.elements.sublist(1);
|
|
return f.call(args);
|
|
}
|
|
}
|
|
}
|
|
|
|
String PRINT(MalType x) => printer.pr_str(x);
|
|
|
|
String rep(String x) {
|
|
return PRINT(EVAL(READ(x), replEnv));
|
|
}
|
|
|
|
const prompt = 'user> ';
|
|
main() {
|
|
setupEnv();
|
|
while (true) {
|
|
stdout.write(prompt);
|
|
var input = stdin.readLineSync();
|
|
if (input == null) return;
|
|
var output;
|
|
try {
|
|
output = rep(input);
|
|
} on reader.ParseException catch (e) {
|
|
stdout.writeln("Error: '${e.message}'");
|
|
continue;
|
|
} on NotFoundException catch (e) {
|
|
stdout.writeln("Error: '${e.value}' not found");
|
|
continue;
|
|
} on reader.NoInputException {
|
|
continue;
|
|
}
|
|
stdout.writeln(output);
|
|
}
|
|
}
|