diff options
Diffstat (limited to 'js-runtime/reflect.js')
| -rw-r--r-- | js-runtime/reflect.js | 543 |
1 files changed, 543 insertions, 0 deletions
diff --git a/js-runtime/reflect.js b/js-runtime/reflect.js new file mode 100644 index 0000000..0662ea5 --- /dev/null +++ b/js-runtime/reflect.js @@ -0,0 +1,543 @@ +class Char { + constructor(codepoint) { + this.codepoint = codepoint; + } + toString() { + let ch = String.fromCodePoint(this.codepoint); + if (ch.match(/[a-zA-Z0-9$[\]().]/)) return `#\\${ch}`; + return `#\\x${this.codepoint.toString(16)}`; + } +} +class Eof { toString() { return "#<eof>"; } } +class Nil { toString() { return "#nil"; } } +class Null { toString() { return "()"; } } +class Unspecified { toString() { return "#<unspecified>"; } } + +class Complex { + constructor(real, imag) { + this.real = real; + this.imag = imag; + } + toString() { + return `${flonum_to_string(this.real)}+${flonum_to_string(this.imag)}i`; + } +} +class Fraction { + constructor(num, denom) { + this.num = num; + this.denom = denom; + } + toString() { + return `${this.num}/${this.denom}`; + } +} + +class HeapObject { + constructor(reflector, obj) { + this.reflector = reflector; + this.obj = obj; + } + repr() { return this.toString(); } // Default implementation. +} + +class Pair extends HeapObject { + toString() { return "#<pair>"; } + repr() { + let car_repr = repr(this.reflector.car(this)); + let cdr_repr = repr(this.reflector.cdr(this)); + if (cdr_repr == '()') + return `(${car_repr})`; + if (cdr_repr.charAt(0) == '(') + return `(${car_repr} ${cdr_repr.substring(1)}`; + return `(${car_repr} . ${cdr_repr})`; + } +} +class MutablePair extends Pair { toString() { return "#<mutable-pair>"; } } + +class Vector extends HeapObject { + toString() { return "#<vector>"; } + repr() { + let len = this.reflector.vector_length(this); + let out = '#('; + for (let i = 0; i < len; i++) { + if (i) out += ' '; + out += repr(this.reflector.vector_ref(this, i)); + } + out += ')'; + return out; + } +} +class MutableVector extends Vector { + toString() { return "#<mutable-vector>"; } +} + +class Bytevector extends HeapObject { + toString() { return "#<bytevector>"; } + repr() { + let len = this.reflector.bytevector_length(this); + let out = '#vu8('; + for (let i = 0; i < len; i++) { + if (i) out += ' '; + out += this.reflector.bytevector_ref(this, i); + } + out += ')'; + return out; + } +} +class MutableBytevector extends Bytevector { + toString() { return "#<mutable-bytevector>"; } +} + +class Bitvector extends HeapObject { + toString() { return "#<bitvector>"; } + repr() { + let len = this.reflector.bitvector_length(this); + let out = '#*'; + for (let i = 0; i < len; i++) { + out += this.reflector.bitvector_ref(this, i) ? '1' : '0'; + } + return out; + } +} +class MutableBitvector extends Bitvector { + toString() { return "#<mutable-bitvector>"; } +} + +class MutableString extends HeapObject { + toString() { return "#<mutable-string>"; } + repr() { return this.reflector.string_value(this); } +} + +class Procedure extends HeapObject { + toString() { return "#<procedure>"; } + call(...arg) { + return this.reflector.call(this, ...arg); + } +} + +class Sym extends HeapObject { + toString() { return "#<symbol>"; } + repr() { return this.reflector.symbol_name(this); } +} + +class Keyword extends HeapObject { + toString() { return "#<keyword>"; } + repr() { return `#:${this.reflector.keyword_name(this)}`; } +} + +class Variable extends HeapObject { toString() { return "#<variable>"; } } +class AtomicBox extends HeapObject { toString() { return "#<atomic-box>"; } } +class HashTable extends HeapObject { toString() { return "#<hash-table>"; } } +class WeakTable extends HeapObject { toString() { return "#<weak-table>"; } } +class Fluid extends HeapObject { toString() { return "#<fluid>"; } } +class DynamicState extends HeapObject { toString() { return "#<dynamic-state>"; } } +class Syntax extends HeapObject { toString() { return "#<syntax>"; } } +class Port extends HeapObject { toString() { return "#<port>"; } } +class Struct extends HeapObject { toString() { return "#<struct>"; } } + +function instantiate_streaming(path, imports) { + if (typeof fetch !== 'undefined') + return WebAssembly.instantiateStreaming(fetch(path), imports); + let bytes; + if (typeof read !== 'undefined') { + bytes = read(path, 'binary'); + } else if (typeof readFile !== 'undefined') { + bytes = readFile(path); + } else { + let fs = require('fs'); + bytes = fs.readFileSync(path); + } + return WebAssembly.instantiate(bytes, imports); +} + +class Scheme { + #instance; + #abi; + constructor(instance, abi) { + this.#instance = instance; + this.#abi = abi; + } + + static async reflect(abi) { + let { module, instance } = + await instantiate_streaming('js-runtime/reflect.wasm', { + abi, + rt: { + wtf8_to_string(wtf8) { return wtf8_to_string(wtf8); }, + string_to_wtf8(str) { return string_to_wtf8(str); }, + } + }); + return new Scheme(instance, abi); + } + + init_module(mod) { + mod.set_debug_handler({ + debug_str(x) { console.log(`debug: ${x}`); }, + debug_str_i32(x, y) { console.log(`debug: ${x}: ${y}`); }, + debug_str_scm: (x, y) => { + console.log(`debug: ${x}: ${repr(this.to_js(y))}`); + }, + }); + let proc = new Procedure(this, mod.get_export('$load').value) + return proc.call(); + } + static async load_main(path, abi, user_imports = {}) { + let mod = await SchemeModule.fetch_and_instantiate(path, abi, user_imports); + let reflect = await mod.reflect(); + return reflect.init_module(mod); + } + async load_extension(path) { + let mod = await SchemeModule.fetch_and_instantiate(path, this.#abi); + return this.init_module(mod); + } + + #to_scm(js) { + let api = this.#instance.exports; + if (typeof(js) == 'number') { + return api.scm_from_f64(js); + } else if (typeof(js) == 'bigint') { + if (BigInt(api.scm_most_negative_fixnum()) <= js + && js <= BigInt(api.scm_most_positive_fixnum())) + return api.scm_from_fixnum(Number(js)); + return api.scm_from_bignum(js); + } else if (typeof(js) == 'boolean') { + return js ? api.scm_true() : api.scm_false(); + } else if (typeof(js) == 'string') { + return api.scm_from_string(js); + } else if (typeof(js) == 'object') { + if (js instanceof Eof) return api.scm_eof(); + if (js instanceof Nil) return api.scm_nil(); + if (js instanceof Null) return api.scm_null(); + if (js instanceof Unspecified) return api.scm_unspecified(); + if (js instanceof Char) return api.scm_from_char(js.codepoint); + if (js instanceof HeapObject) return js.obj; + if (js instanceof Fraction) + return api.scm_from_fraction(this.#to_scm(js.num), + this.#to_scm(js.denom)); + if (js instanceof Complex) + return api.scm_from_complex(js.real, js.imag); + return api.scm_from_extern(js); + } else { + throw new Error(`unexpected; ${typeof(js)}`); + } + } + + to_js(scm) { + let api = this.#instance.exports; + let descr = api.describe(scm); + let handlers = { + fixnum: () => BigInt(api.fixnum_value(scm)), + char: () => new Char(api.char_value(scm)), + true: () => true, + false: () => false, + eof: () => new Eof, + nil: () => new Nil, + null: () => new Null, + unspecified: () => new Unspecified, + flonum: () => api.flonum_value(scm), + bignum: () => api.bignum_value(scm), + complex: () => new Complex(api.complex_real(scm), + api.complex_imag(scm)), + fraction: () => new Fraction(this.to_js(api.fraction_num(scm)), + this.to_js(api.fraction_denom(scm))), + pair: () => new Pair(this, scm), + 'mutable-pair': () => new MutablePair(this, scm), + vector: () => new Vector(this, scm), + 'mutable-vector': () => new MutableVector(this, scm), + bytevector: () => new Bytevector(this, scm), + 'mutable-bytevector': () => new MutableBytevector(this, scm), + bitvector: () => new Bitvector(this, scm), + 'mutable-bitvector': () => new MutableBitvector(this, scm), + string: () => api.string_value(scm), + 'mutable-string': () => new MutableString(this, scm), + procedure: () => new Procedure(this, scm), + symbol: () => new Sym(this, scm), + keyword: () => new Keyword(this, scm), + variable: () => new Variable(this, scm), + 'atomic-box': () => new AtomicBox(this, scm), + 'hash-table': () => new HashTable(this, scm), + 'weak-table': () => new WeakTable(this, scm), + fluid: () => new Fluid(this, scm), + 'dynamic-state': () => new DynamicState(this, scm), + syntax: () => new Syntax(this, scm), + port: () => new Port(this, scm), + struct: () => new Struct(this, scm), + 'extern-ref': () => api.extern_value(scm) + }; + let handler = handlers[descr]; + return handler ? handler() : scm; + } + + call(func, ...args) { + let api = this.#instance.exports; + let argv = api.make_vector(args.length + 1, api.scm_false()); + func = this.#to_scm(func); + api.vector_set(argv, 0, func); + for (let [idx, arg] of args.entries()) + api.vector_set(argv, idx + 1, this.#to_scm(arg)); + argv = api.call(func, argv); + let results = []; + for (let idx = 0; idx < api.vector_length(argv); idx++) + results.push(this.to_js(api.vector_ref(argv, idx))) + return results; + } + + car(x) { return this.to_js(this.#instance.exports.car(x.obj)); } + cdr(x) { return this.to_js(this.#instance.exports.cdr(x.obj)); } + + vector_length(x) { return this.#instance.exports.vector_length(x.obj); } + vector_ref(x, i) { + return this.to_js(this.#instance.exports.vector_ref(x.obj, i)); + } + + bytevector_length(x) { + return this.#instance.exports.bytevector_length(x.obj); + } + bytevector_ref(x, i) { + return this.#instance.exports.bytevector_ref(x.obj, i); + } + + bitvector_length(x) { + return this.#instance.exports.bitvector_length(x.obj); + } + bitvector_ref(x, i) { + return this.#instance.exports.bitvector_ref(x.obj, i) == 1; + } + + string_value(x) { return this.#instance.exports.string_value(x.obj); } + symbol_name(x) { return this.#instance.exports.symbol_name(x.obj); } + keyword_name(x) { return this.#instance.exports.keyword_name(x.obj); } +} + +class SchemeTrapError extends Error { + constructor(tag, data) { super(); this.tag = tag; this.data = data; } + // FIXME: data is raw Scheme object; would need to be reflected to + // have a toString. + toString() { return `SchemeTrap(${this.tag}, <data>)`; } +} + +function flonum_to_string(f64) { + if (Object.is(f64, -0)) { + return '-0.0'; + } else if (Number.isFinite(f64)) { + let repr = f64 + ''; + return /^-?[0-9]+$/.test(repr) ? repr + '.0' : repr; + } else if (Number.isNaN(f64)) { + return '+nan.0'; + } else { + return f64 < 0 ? '-inf.0' : '+inf.0'; + } +} + +let wtf8_helper; + +function wtf8_to_string(wtf8) { + let { as_iter, iter_next } = wtf8_helper.exports; + let codepoints = []; + let iter = as_iter(wtf8); + for (let cp = iter_next(iter); cp != -1; cp = iter_next(iter)) + codepoints.push(cp); + return String.fromCodePoint(...codepoints); +} + +function string_to_wtf8(str) { + let { string_builder, builder_push_codepoint, finish_builder } = + wtf8_helper.exports; + let builder = string_builder() + for (let cp of str) + builder_push_codepoint(builder, cp.codePointAt(0)); + return finish_builder(builder); +} + +async function load_wtf8_helper_module() { + if (wtf8_helper) return; + let { module, instance } = await instantiate_streaming("js-runtime/wtf8.wasm"); + wtf8_helper = instance; +} + +class SchemeModule { + #instance; + #io_handler; + #debug_handler; + static #rt = { + bignum_from_i32(n) { return BigInt(n); }, + bignum_from_i64(n) { return n; }, + bignum_from_u64(n) { return n < 0n ? 0xffff_ffff_ffff_ffffn + (n + 1n) : n; }, + bignum_is_i64(n) { + return -0x8000_0000_0000_0000n <= n && n <= 0x7FFF_FFFF_FFFF_FFFFn; + }, + bignum_is_u64(n) { + return 0n <= n && n <= 0xFFFF_FFFF_FFFF_FFFFn; + }, + // This truncates; see https://tc39.es/ecma262/#sec-tobigint64. + bignum_get_i64(n) { return n; }, + + bignum_add(a, b) { return BigInt(a) + BigInt(b) }, + bignum_sub(a, b) { return BigInt(a) - BigInt(b) }, + bignum_mul(a, b) { return BigInt(a) * BigInt(b) }, + bignum_lsh(a, b) { return BigInt(a) << BigInt(b) }, + bignum_rsh(a, b) { return BigInt(a) >> BigInt(b) }, + bignum_quo(a, b) { return BigInt(a) / BigInt(b) }, + bignum_rem(a, b) { return BigInt(a) % BigInt(b) }, + bignum_mod(a, b) { + let r = BigInt(a) % BigInt(b); + if ((b > 0n && r < 0n) || (b < 0n && r > 0n)) { + return b + r; + } else { + return r; + } + }, + bignum_gcd(a, b) { + a = BigInt(a); + b = BigInt(b); + if (a < 0n) { a = -a; } + if (b < 0n) { b = -b; } + if (a == 0n) { return b; } + if (b == 0n) { return a; } + + let r; + while (b != 0n) { + r = a % b; + a = b; + b = r; + } + return a; + }, + + bignum_logand(a, b) { return BigInt(a) & BigInt(b); }, + bignum_logior(a, b) { return BigInt(a) | BigInt(b); }, + bignum_logxor(a, b) { return BigInt(a) ^ BigInt(b); }, + bignum_logsub(a, b) { return BigInt(a) & (~ BigInt(b)); }, + + bignum_lt(a, b) { return a < b; }, + bignum_le(a, b) { return a <= b; }, + bignum_eq(a, b) { return a == b; }, + + bignum_to_f64(n) { return Number(n); }, + + f64_is_nan(n) { return Number.isNaN(n); }, + f64_is_infinite(n) { return !Number.isFinite(n); }, + + flonum_to_string, + + string_upcase: Function.call.bind(String.prototype.toUpperCase), + string_downcase: Function.call.bind(String.prototype.toLowerCase), + + make_weak_map() { return new WeakMap; }, + weak_map_get(map, k) { return map.get(k); }, + weak_map_set(map, k, v) { return map.set(k, v); }, + weak_map_delete(map, k) { return map.delete(k); }, + + fsqrt: Math.sqrt, + fsin: Math.sin, + fcos: Math.cos, + ftan: Math.tan, + fasin: Math.asin, + facos: Math.acos, + fatan: Math.atan, + fatan2: Math.atan2, + flog: Math.log, + fexp: Math.exp, + + jiffies_per_second() { return 1000; }, + current_jiffy() { return BigInt(Math.floor(performance.now())); }, + current_second() { return Date.now() / 1000; }, + + // Wrap in functions to allow for lazy loading of the wtf8 + // module. + wtf8_to_string(wtf8) { return wtf8_to_string(wtf8); }, + string_to_wtf8(str) { return string_to_wtf8(str); }, + + die(tag, data) { throw new SchemeTrapError(tag, data); } + }; + + constructor(instance) { + this.#instance = instance; + let read_stdin = () => ''; + if (typeof printErr === 'function') { + // On the console, try to use 'write' (v8) or 'putstr' (sm), + // as these don't add an extraneous newline. Unfortunately + // JSC doesn't have a printer that doesn't add a newline. + let write_no_newline = + typeof write === 'function' ? write + : typeof putstr === 'function' ? putstr : print; + this.#io_handler = { + write_stdout: write_no_newline, + write_stderr: printErr, + read_stdin + }; + } else { + this.#io_handler = { + write_stdout: console.log, + write_stderr: console.error, + read_stdin + } + } + this.#debug_handler = { + debug_str(x) { console.log(`debug: ${x}`); }, + debug_str_i32(x, y) { console.log(`debug: ${x}: ${y}`); }, + debug_str_scm(x, y) { console.log(`debug: ${x}: #<scm>`); }, + } + } + static async fetch_and_instantiate(path, imported_abi, user_imports = {}) { + await load_wtf8_helper_module(); + let io = { + write_stdout(str) { mod.#io_handler.write_stdout(str); }, + write_stderr(str) { mod.#io_handler.write_stderr(str); }, + read_stdin() { return mod.#io_handler.read_stdin(); }, + } + let debug = { + debug_str(x) { mod.#debug_handler.debug_str(x); }, + debug_str_i32(x, y) { mod.#debug_handler.debug_str_i32(x, y); }, + debug_str_scm(x, y) { mod.#debug_handler.debug_str_scm(x, y); }, + } + let imports = { + rt: SchemeModule.#rt, + abi: imported_abi, + debug, io, ...user_imports + }; + let { module, instance } = await instantiate_streaming(path, imports); + let mod = new SchemeModule(instance); + return mod; + } + set_io_handler(h) { this.#io_handler = h; } + set_debug_handler(h) { this.#debug_handler = h; } + all_exports() { return this.#instance.exports; } + exported_abi() { + let abi = {} + for (let [k, v] of Object.entries(this.all_exports())) { + if (k.startsWith("$")) + abi[k] = v; + } + return abi; + } + exports() { + let ret = {} + for (let [k, v] of Object.entries(this.all_exports())) { + if (!k.startsWith("$")) + ret[k] = v; + } + return ret; + } + get_export(name) { + if (name in this.all_exports()) + return this.all_exports()[name]; + throw new Error(`unknown export: ${name}`) + } + async reflect() { + return await Scheme.reflect(this.exported_abi()); + } +} + +function repr(obj) { + if (obj instanceof HeapObject) + return obj.repr(); + if (typeof obj === 'boolean') + return obj ? '#t' : '#f'; + if (typeof obj === 'number') + return flonum_to_string(obj); + if (typeof obj === 'string') + // FIXME: Improve to match Scheme. + return '"' + obj.replace(/(["\\])/g, '\\$1') + '"'; + return obj + ''; +} |