silverbullet/common/space_lua/runtime.ts

737 lines
19 KiB
TypeScript

import type { ASTCtx, LuaFunctionBody } from "./ast.ts";
import { evalStatement } from "$common/space_lua/eval.ts";
import { asyncQuickSort, evalPromiseValues } from "$common/space_lua/util.ts";
export type LuaType =
| "nil"
| "boolean"
| "number"
| "string"
| "table"
| "function"
| "userdata"
| "thread";
// These types are for documentation only
export type LuaValue = any;
export type JSValue = any;
export interface ILuaFunction {
call(sf: LuaStackFrame, ...args: LuaValue[]): Promise<LuaValue> | LuaValue;
toString(): string;
}
export interface ILuaSettable {
set(key: LuaValue, value: LuaValue, sf?: LuaStackFrame): void;
}
export interface ILuaGettable {
get(key: LuaValue, sf?: LuaStackFrame): LuaValue | undefined;
}
export class LuaEnv implements ILuaSettable, ILuaGettable {
variables = new Map<string, LuaValue>();
constructor(readonly parent?: LuaEnv) {
}
setLocal(name: string, value: LuaValue) {
this.variables.set(name, value);
}
set(key: string, value: LuaValue, sf?: LuaStackFrame): void {
if (this.variables.has(key) || !this.parent) {
this.variables.set(key, value);
} else {
this.parent.set(key, value, sf);
}
}
has(key: string): boolean {
if (this.variables.has(key)) {
return true;
}
if (this.parent) {
return this.parent.has(key);
}
return false;
}
get(
name: string,
sf?: LuaStackFrame,
): Promise<LuaValue> | LuaValue | undefined {
if (this.variables.has(name)) {
return this.variables.get(name);
}
if (this.parent) {
return this.parent.get(name, sf);
}
return undefined;
}
/**
* Lists all keys in the environment including its parents
*/
keys(): string[] {
const keys = Array.from(this.variables.keys());
if (this.parent) {
return keys.concat(this.parent.keys());
}
return keys;
}
}
export class LuaStackFrame {
constructor(
readonly threadLocal: LuaEnv,
readonly astCtx: ASTCtx | null,
readonly parent?: LuaStackFrame,
) {
}
withCtx(ctx: ASTCtx): LuaStackFrame {
return new LuaStackFrame(this.threadLocal, ctx, this);
}
static lostFrame = new LuaStackFrame(new LuaEnv(), null);
}
export class LuaMultiRes {
values: any[];
constructor(values: LuaValue[] | LuaValue) {
if (values instanceof LuaMultiRes) {
this.values = values.values;
} else {
this.values = Array.isArray(values) ? values : [values];
}
}
unwrap(): any {
if (this.values.length === 0) {
return null;
}
return this.values[0];
}
// Takes an array of either LuaMultiRes or LuaValue and flattens them into a single LuaMultiRes
flatten(): LuaMultiRes {
const result: any[] = [];
for (const value of this.values) {
if (value instanceof LuaMultiRes) {
result.push(...value.values);
} else {
result.push(value);
}
}
return new LuaMultiRes(result);
}
}
export function singleResult(value: any): any {
if (value instanceof LuaMultiRes) {
return value.unwrap();
} else {
return value;
}
}
export class LuaFunction implements ILuaFunction {
private capturedEnv: LuaEnv;
constructor(readonly body: LuaFunctionBody, closure: LuaEnv) {
this.capturedEnv = closure;
}
call(sf: LuaStackFrame, ...args: LuaValue[]): Promise<LuaValue> {
// Create a new environment that chains to the captured environment
const env = new LuaEnv(this.capturedEnv);
if (!sf) {
console.trace(sf);
}
// Set _CTX to the thread local environment from the stack frame
env.setLocal("_CTX", sf.threadLocal);
// Assign the passed arguments to the parameters
for (let i = 0; i < this.body.parameters.length; i++) {
const paramName = this.body.parameters[i];
if (paramName === "...") {
// Handle varargs by creating a table with all remaining arguments
const varargs = new LuaTable();
// Include all remaining arguments (might be none)
for (let j = i; j < args.length; j++) {
varargs.set(j - i + 1, args[j], sf);
}
env.setLocal("...", varargs);
break;
}
let arg = args[i];
if (arg === undefined) {
arg = null;
}
env.setLocal(this.body.parameters[i], arg);
}
// If the function has varargs parameter but it wasn't set above, set an empty varargs table
if (this.body.parameters.includes("...") && !env.has("...")) {
env.setLocal("...", new LuaTable());
}
const resolvedArgs = evalPromiseValues(args);
if (resolvedArgs instanceof Promise) {
return resolvedArgs.then((args) => this.callWithArgs(args, env, sf));
}
return this.callWithArgs(resolvedArgs, env, sf);
}
toString(): string {
return `<lua function(${this.body.parameters.join(", ")})>`;
}
private callWithArgs(
args: LuaValue[],
env: LuaEnv,
sf: LuaStackFrame,
): Promise<LuaValue> {
// Set up parameters and varargs
for (let i = 0; i < this.body.parameters.length; i++) {
const paramName = this.body.parameters[i];
if (paramName === "...") {
const varargs = new LuaTable();
for (let j = i; j < args.length; j++) {
if (args[j] instanceof Promise) {
return Promise.all(args.slice(i)).then((resolvedArgs) => {
const varargs = new LuaTable();
resolvedArgs.forEach((val, idx) => varargs.set(idx + 1, val, sf));
env.setLocal("...", varargs);
return this.evalBody(env, sf);
});
}
varargs.set(j - i + 1, args[j], sf);
}
env.setLocal("...", varargs);
break;
}
env.setLocal(paramName, args[i] ?? null);
}
// Ensure empty varargs table exists if needed
if (this.body.parameters.includes("...") && !env.has("...")) {
env.setLocal("...", new LuaTable());
}
return this.evalBody(env, sf);
}
private async evalBody(
env: LuaEnv,
sf: LuaStackFrame,
): Promise<LuaValue> {
try {
await evalStatement(this.body.block, env, sf);
} catch (e: any) {
if (e instanceof LuaReturn) {
if (e.values.length === 0) {
return;
} else if (e.values.length === 1) {
return e.values[0];
} else {
return new LuaMultiRes(e.values);
}
} else {
throw e;
}
}
}
}
export class LuaNativeJSFunction implements ILuaFunction {
constructor(readonly fn: (...args: JSValue[]) => JSValue) {
}
// Performs automatic conversion between Lua and JS values
call(_sf: LuaStackFrame, ...args: LuaValue[]): Promise<LuaValue> | LuaValue {
const result = this.fn(...args.map(luaValueToJS));
if (result instanceof Promise) {
return result.then(jsToLuaValue);
} else {
return jsToLuaValue(result);
}
}
toString(): string {
return `<native js function: ${this.fn.name}>`;
}
}
export class LuaBuiltinFunction implements ILuaFunction {
constructor(
readonly fn: (sf: LuaStackFrame, ...args: LuaValue[]) => LuaValue,
) {
}
call(sf: LuaStackFrame, ...args: LuaValue[]): Promise<LuaValue> | LuaValue {
// _CTX is already available via the stack frame
return this.fn(sf, ...args);
}
toString(): string {
return `<builtin lua function>`;
}
}
export class LuaTable implements ILuaSettable, ILuaGettable {
// To optimize the table implementation we use a combination of different data structures
// When tables are used as maps, the common case is that they are string keys, so we use a simple object for that
private stringKeys: Record<string, any>;
// Other keys we can support using a Map as a fallback
private otherKeys: Map<any, any> | null;
// When tables are used as arrays, we use a native JavaScript array for that
private arrayPart: any[];
public metatable: LuaTable | null;
constructor(init?: any[] | Record<string, any>) {
// For efficiency and performance reasons we pre-allocate these (modern JS engines are very good at optimizing this)
this.arrayPart = Array.isArray(init) ? init : [];
this.stringKeys = init && !Array.isArray(init) ? init : {};
this.otherKeys = null; // Only create this when needed
this.metatable = null;
}
get length(): number {
return this.arrayPart.length;
}
keys(): any[] {
const keys: any[] = Object.keys(this.stringKeys);
for (let i = 0; i < this.arrayPart.length; i++) {
keys.push(i + 1);
}
if (this.otherKeys) {
for (const key of this.otherKeys.keys()) {
keys.push(key);
}
}
return keys;
}
has(key: LuaValue) {
if (typeof key === "string") {
return this.stringKeys[key] !== undefined;
} else if (Number.isInteger(key) && key >= 1) {
return this.arrayPart[key - 1] !== undefined;
} else if (this.otherKeys) {
return this.otherKeys.has(key);
}
return false;
}
rawSet(key: LuaValue, value: LuaValue) {
if (typeof key === "string") {
this.stringKeys[key] = value;
} else if (Number.isInteger(key) && key >= 1) {
this.arrayPart[key - 1] = value;
} else {
if (!this.otherKeys) {
this.otherKeys = new Map();
}
this.otherKeys.set(key, value);
}
}
set(
key: LuaValue,
value: LuaValue,
sf?: LuaStackFrame,
): Promise<void> | void {
if (this.metatable && this.metatable.has("__newindex") && !this.has(key)) {
// Invoke the meta table!
const metaValue = this.metatable.get("__newindex", sf);
if (metaValue.then) {
// This is a promise, we need to wait for it
return metaValue.then((metaValue: any) => {
return luaCall(metaValue, [this, key, value], metaValue.ctx, sf);
});
} else {
return luaCall(metaValue, [this, key, value], metaValue.ctx, sf);
}
}
// Just set the value
this.rawSet(key, value);
}
rawGet(key: LuaValue): LuaValue | null {
if (typeof key === "string") {
return this.stringKeys[key];
} else if (Number.isInteger(key) && key >= 1) {
return this.arrayPart[key - 1];
} else if (this.otherKeys) {
return this.otherKeys.get(key);
}
}
get(key: LuaValue, sf?: LuaStackFrame): LuaValue | Promise<LuaValue> | null {
const value = this.rawGet(key);
if (value === undefined || value === null) {
if (this.metatable && this.metatable.has("__index")) {
// Invoke the meta table
const metaValue = this.metatable.get("__index", sf);
if (metaValue.then) {
// Got a promise, we need to wait for it
return metaValue.then((metaValue: any) => {
if (metaValue.call) {
return metaValue.call(sf, this, key);
} else if (metaValue instanceof LuaTable) {
return metaValue.get(key, sf);
} else {
throw new Error("Meta table __index must be a function or table");
}
});
} else {
if (metaValue.call) {
return metaValue.call(sf, this, key);
} else if (metaValue instanceof LuaTable) {
return metaValue.get(key, sf);
} else {
throw new Error("Meta table __index must be a function or table");
}
}
} else {
return null;
}
} else {
return value;
}
}
insert(value: LuaValue, pos: number) {
this.arrayPart.splice(pos - 1, 0, value);
}
remove(pos: number) {
this.arrayPart.splice(pos - 1, 1);
}
async sort(fn?: ILuaFunction, sf?: LuaStackFrame) {
if (fn && sf) {
this.arrayPart = await asyncQuickSort(this.arrayPart, async (a, b) => {
return (await fn.call(sf, a, b)) ? -1 : 1;
});
} else {
this.arrayPart.sort();
}
}
asJSObject(): Record<string, any> {
const result: Record<string, any> = {};
for (const key of this.keys()) {
result[key] = luaValueToJS(this.get(key));
}
return result;
}
asJSArray(): any[] {
return this.arrayPart.map(luaValueToJS);
}
async toStringAsync(): Promise<string> {
if (this.metatable?.has("__tostring")) {
const metaValue = await this.metatable.get("__tostring");
if (metaValue.call) {
return metaValue.call(LuaStackFrame.lostFrame, this);
} else {
throw new Error("Meta table __tostring must be a function");
}
}
let result = "{";
let first = true;
for (const key of this.keys()) {
if (first) {
first = false;
} else {
result += ", ";
}
if (typeof key === "number") {
result += await luaToString(this.get(key));
continue;
}
if (typeof key === "string") {
result += key;
} else {
result += "[" + key + "]";
}
result += " = " + await luaToString(this.get(key));
}
result += "}";
return result;
}
}
export type LuaLValueContainer = { env: ILuaSettable; key: LuaValue };
export function luaSet(obj: any, key: any, value: any, sf: LuaStackFrame) {
if (!obj) {
throw new LuaRuntimeError(
`Not a settable object: nil`,
sf,
);
}
if (obj instanceof LuaTable || obj instanceof LuaEnv) {
obj.set(key, value, sf);
} else {
obj[key] = value;
}
}
export function luaGet(
obj: any,
key: any,
sf: LuaStackFrame,
): Promise<any> | any {
if (!obj) {
throw new LuaRuntimeError(
`Attempting to index a nil value`,
sf,
);
}
if (key === null || key === undefined) {
throw new LuaRuntimeError(
`Attempting to index with a nil key`,
sf,
);
}
if (obj instanceof LuaTable || obj instanceof LuaEnv) {
return obj.get(key, sf);
} else if (typeof key === "number") {
return obj[key - 1];
} else {
// Native JS object
const val = obj[key];
if (typeof val === "function") {
// Automatically bind the function to the object
return val.bind(obj);
} else {
return val;
}
}
}
export function luaLen(obj: any): number {
if (obj instanceof LuaTable) {
return obj.length;
} else if (Array.isArray(obj)) {
return obj.length;
} else {
return 0;
}
}
export function luaCall(
fn: any,
args: any[],
ctx: ASTCtx,
sf?: LuaStackFrame,
): any {
if (!fn) {
throw new LuaRuntimeError(
`Attempting to call a nil value`,
(sf || LuaStackFrame.lostFrame).withCtx(ctx),
);
}
if (typeof fn === "function") {
const jsArgs = args.map(luaValueToJS);
// Native JS function
return fn(...jsArgs);
}
if (!fn.call) {
throw new LuaRuntimeError(
`Attempting to call a non-callable value`,
(sf || LuaStackFrame.lostFrame).withCtx(ctx),
);
}
return fn.call((sf || LuaStackFrame.lostFrame).withCtx(ctx), ...args);
}
export function luaKeys(val: any): any[] {
if (val instanceof LuaTable) {
return val.keys();
} else if (Array.isArray(val)) {
return val.map((_, i) => i + 1);
} else {
return Object.keys(val);
}
}
export function luaTypeOf(val: any): LuaType {
if (val === null || val === undefined) {
return "nil";
} else if (typeof val === "boolean") {
return "boolean";
} else if (typeof val === "number") {
return "number";
} else if (typeof val === "string") {
return "string";
} else if (val instanceof LuaTable) {
return "table";
} else if (Array.isArray(val)) {
return "table";
} else if (typeof val === "function" || val.call) {
return "function";
} else {
return "userdata";
}
}
// Both `break` and `return` are implemented by exception throwing
export class LuaBreak extends Error {
}
export class LuaReturn extends Error {
constructor(readonly values: LuaValue[]) {
super();
}
}
export class LuaRuntimeError extends Error {
constructor(
override readonly message: string,
public sf: LuaStackFrame,
cause?: Error,
) {
super(message, cause);
}
toPrettyString(code: string): string {
if (!this.sf || !this.sf.astCtx?.from || !this.sf.astCtx?.to) {
return this.toString();
}
let traceStr = "";
let current: LuaStackFrame | undefined = this.sf;
while (current) {
const ctx = current.astCtx;
if (!ctx || !ctx.from || !ctx.to) {
break;
}
// Find the line and column
let line = 1;
let column = 0;
let lastNewline = -1;
for (let i = 0; i < ctx.from; i++) {
if (code[i] === "\n") {
line++;
lastNewline = i;
column = 0;
} else {
column++;
}
}
// Get the full line of code for context
const lineStart = lastNewline + 1;
const lineEnd = code.indexOf("\n", ctx.from);
const codeLine = code.substring(
lineStart,
lineEnd === -1 ? undefined : lineEnd,
);
// Add position indicator
const pointer = " ".repeat(column) + "^";
traceStr += `* ${ctx.ref || "(unknown source)"} @ ${line}:${column}:\n` +
` ${codeLine}\n` +
` ${pointer}\n`;
current = current.parent;
}
return `LuaRuntimeError: ${this.message}\nStack trace:\n${traceStr}`;
}
override toString() {
return `LuaRuntimeError: ${this.message} at ${this.sf.astCtx?.from}, ${this.sf.astCtx?.to}`;
}
}
export function luaTruthy(value: any): boolean {
if (value === undefined || value === null || value === false) {
return false;
}
if (value instanceof LuaTable) {
return value.length > 0;
}
return true;
}
export function luaToString(value: any): string | Promise<string> {
if (value === null || value === undefined) {
return "nil";
}
if (value.toStringAsync) {
return value.toStringAsync();
}
if (value.toString) {
return value.toString();
}
return String(value);
}
export function jsToLuaValue(value: any): any {
if (value instanceof Promise) {
return value.then(luaValueToJS);
}
if (value instanceof LuaTable) {
return value;
} else if (Array.isArray(value)) {
const table = new LuaTable();
for (let i = 0; i < value.length; i++) {
table.set(i + 1, jsToLuaValue(value[i]));
}
return table;
} else if (typeof value === "object") {
const table = new LuaTable();
for (const key in value) {
table.set(key, jsToLuaValue(value[key]));
}
return table;
} else if (typeof value === "function") {
return new LuaNativeJSFunction(value);
} else {
return value;
}
}
// Inverse of jsToLuaValue
export function luaValueToJS(value: any): any {
if (value instanceof Promise) {
return value.then(luaValueToJS);
}
if (value instanceof LuaTable) {
// We'll go a bit on heuristics here
// If the table has a length > 0 we'll assume it's a pure array
// Otherwise we'll assume it's a pure object
if (value.length > 0) {
const result = [];
for (let i = 0; i < value.length; i++) {
result.push(luaValueToJS(value.get(i + 1)));
}
return result;
} else {
const result: Record<string, any> = {};
for (const key of value.keys()) {
result[key] = luaValueToJS(value.get(key));
}
return result;
}
} else if (value instanceof LuaNativeJSFunction) {
return (...args: any[]) => {
return jsToLuaValue(value.fn(...args.map(luaValueToJS)));
};
} else {
return value;
}
}