add random tile selection from map to the web tools

3 files changed, 607 insertions, 28 deletions

diff --git a/html/Makefile b/html/Makefile
index 3c969595..9188c4a5 100644
--- a/html/Makefile
+++ b/html/Makefile
@@ -10,6 +10,7 @@ MAKEFILE_DIR := $(dir $(MAKEFILE_PATH))
 
 HTML_ROOT := $(MAKEFILE_DIR)
 GAME_ROOT := $(MAKEFILE_DIR)..
+GO_ROOT := $(GAME_ROOT)/go
 RULES_ROOT := $(GAME_ROOT)/rules
 MAPS_ROOT := $(GAME_ROOT)/maps
 DATA_ROOT := $(GAME_ROOT)/data
@@ -55,12 +56,21 @@ CARDS_YAML := $(foreach dir,$(SETS_SOURCEDIRS),$(wildcard $(dir)/*.yml))
 
 MAKEFILE_LIST := Makefile
 
+FILES_TO_COPY := wasm_exec.js hover-placeholder.png tools.html
+FILES_TO_COPY_TARGETS := $(addprefix $(BUILDDIR)/,$(FILES_TO_COPY))
+
 .PHONY: all clean maps misc
 all: $(HTML) $(RULES_HTML) maps misc $(BLOG_POSTS_HTML)
 
-misc: $(BUILDDIR)/latex-build $(BUILDDIR)/cards-data $(BUILDDIR)/hover-placeholder.png
+misc: $(BUILDDIR)/latex-build $(BUILDDIR)/cards-data $(FILES_TO_COPY_TARGETS) \
+      $(BUILDDIR)/webtools.wasm
+
+$(BUILDDIR)/webtools.wasm:
+	@echo "creating symlink		$@"
+	@if test \( ! \( -d $(@D) \) \) ;then mkdir -p $(@D);fi
+	ln -s $(GO_ROOT)/webtools/webtools.wasm $@ 
 
-$(BUILDDIR)/hover-placeholder.png: hover-placeholder.png
+$(FILES_TO_COPY_TARGETS): $(BUILDDIR)/%: %
 	@echo "copying		$@"
 	@if test \( ! \( -d $(@D) \) \) ;then mkdir -p $(@D);fi
 	$(VERBOSE) cp $< $@
@@ -73,11 +83,6 @@ maps:
 	$(VERBOSE) ln -sfT $(MAPS_ROOT) $(BUILDDIR)/maps
 	$(VERBOSE) $(MAKE) -C $(MAPS_ROOT)
 
-$(BUILDDIR)/tools.html: tools.html
-	@echo "copying		$@"
-	@if test \( ! \( -d $(@D) \) \) ;then mkdir -p $(@D);fi
-	$(VERBOSE) cp $< $@
-
 $(BUILDDIR)/latex-build:
 	@echo "render		cards"
 	$(VERBOSE) $(MAKE) -C $(LATEX_ROOT)
diff --git a/html/tools.html b/html/tools.html
index 5d638ef5..caca608e 100644
--- a/html/tools.html
+++ b/html/tools.html
@@ -68,6 +68,15 @@ body {
 }
   </style>
 
+  <script src="wasm_exec.js"></script>
+
+  <script>
+    const go = new Go();
+    WebAssembly.instantiateStreaming(fetch("webtools.wasm"), go.importObject).then((result) => {
+      go.run(result.instance);
+    });
+  </script>
+
   <script language="javascript" type="text/javascript">
     /*
     @licstart  The following is the entire license notice for the
@@ -93,19 +102,6 @@ body {
     for the JavaScript code in this page.
     */
 
-    // List of houses on the tyrant map
-    let tyrantHouses = Array(
-        {x:1, y:1}, {x:4, y:1}, {x:5, y:1}, {x:8, y:1}, {x:15, y:1},
-        {x:3, y:2}, {x:6, y:2}, {x:12, y:2}, {x:13, y:2}, {x:14, y:2},
-        {x:2, y:3}, {x:14, y:3},
-        {x:2, y:4}, {x:5, y:4}, {x:10, y:4},
-        {x:3, y:5}, {x:6, y:4}, {x:9, y:4},
-        {x:7, y:6}, {x:10, y:6},
-        {x:13, y:10},
-        {x:4, y:11},
-        {x:3, y:15}, {x:9, y:15}, {x:14, y:15},
-    );
-
     // return a random number between 1 and max
     function randomInt(max) {
       return Math.floor(Math.random() * Number(max)) + 1;
@@ -200,11 +196,26 @@ body {
         return false;
       }
 
-      document.getElementById("random_house_tyrant_form").onsubmit = function() {
-        let idx = Math.floor(Math.random() * tyrantHouses.length);
-        let house = tyrantHouses[idx];
-        result.innerHTML = "Random house: " + (idx + 1) + " at (x:" + house.x + ", y:"
-                           + house.y + ")";
+      document.getElementById("random_map_tile_form").onsubmit = function() {
+        const mapName = document.getElementById("random_map_tile_map_select").value;
+        const mapUrl = "maps/" + mapName + ".yml"
+        const symbols =  document.getElementById("random_map_tile_symbols").value.split(" ");
+        const request = new XMLHttpRequest();
+        request.onreadystatechange = function() {
+          if (request.readyState == 4 && request.status == 200) {
+             const pos = randomTileFromSymbol(request.responseText, symbols);
+             if (!pos) {
+               result.innerHTML = "The Go websassembly returned no value";
+             } else if (typeof pos === "string" || pos instanceof String) {
+               result.innerHTML = "An error occured: " + pos;
+             } else {
+               result.innerHTML = "Random tile: (x:" + pos.x + ", y:" + pos.y + ")";
+             }
+          }
+        }
+        request.open("GET", mapUrl, true);
+        request.send(null);
+
         return false;
       }
     });
@@ -250,9 +261,18 @@ Random tile within Range
 <h2>The tyrant tools</h2>
 
 <div>
-<form id="random_house_tyrant_form">
-Random house tile
-  <input id="random_house_tyrant_button" value="generate" type="submit">
+<form id="random_map_tile_form">
+Random tile from
+  <select name="map" id="random_map_tile_map_select">
+    <option value="the-tyrant">the-tyrant</option>
+    <option value="2P-ring-street">2P-ring-street</option>
+    <option value="2P-river-king">2P-river-king</option>
+    <option value="3P-ring-street">3P-ring-street</option>
+    <option value="4P-islands">4P-islands</option>
+    <option value="the-kraken">the-kraken</option>
+  </select>
+  <input id="random_map_tile_symbols" value="symbols">
+  <input id="random_map_tile_button" value="generate" type="submit">
 </form>
 </div>
 
diff --git a/html/wasm_exec.js b/html/wasm_exec.js
new file mode 100644
index 00000000..9ce6a20c
--- /dev/null
+++ b/html/wasm_exec.js
@@ -0,0 +1,554 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+"use strict";
+
+(() => {
+	const enosys = () => {
+		const err = new Error("not implemented");
+		err.code = "ENOSYS";
+		return err;
+	};
+
+	if (!globalThis.fs) {
+		let outputBuf = "";
+		globalThis.fs = {
+			constants: { O_WRONLY: -1, O_RDWR: -1, O_CREAT: -1, O_TRUNC: -1, O_APPEND: -1, O_EXCL: -1 }, // unused
+			writeSync(fd, buf) {
+				outputBuf += decoder.decode(buf);
+				const nl = outputBuf.lastIndexOf("\n");
+				if (nl != -1) {
+					console.log(outputBuf.substr(0, nl));
+					outputBuf = outputBuf.substr(nl + 1);
+				}
+				return buf.length;
+			},
+			write(fd, buf, offset, length, position, callback) {
+				if (offset !== 0 || length !== buf.length || position !== null) {
+					callback(enosys());
+					return;
+				}
+				const n = this.writeSync(fd, buf);
+				callback(null, n);
+			},
+			chmod(path, mode, callback) { callback(enosys()); },
+			chown(path, uid, gid, callback) { callback(enosys()); },
+			close(fd, callback) { callback(enosys()); },
+			fchmod(fd, mode, callback) { callback(enosys()); },
+			fchown(fd, uid, gid, callback) { callback(enosys()); },
+			fstat(fd, callback) { callback(enosys()); },
+			fsync(fd, callback) { callback(null); },
+			ftruncate(fd, length, callback) { callback(enosys()); },
+			lchown(path, uid, gid, callback) { callback(enosys()); },
+			link(path, link, callback) { callback(enosys()); },
+			lstat(path, callback) { callback(enosys()); },
+			mkdir(path, perm, callback) { callback(enosys()); },
+			open(path, flags, mode, callback) { callback(enosys()); },
+			read(fd, buffer, offset, length, position, callback) { callback(enosys()); },
+			readdir(path, callback) { callback(enosys()); },
+			readlink(path, callback) { callback(enosys()); },
+			rename(from, to, callback) { callback(enosys()); },
+			rmdir(path, callback) { callback(enosys()); },
+			stat(path, callback) { callback(enosys()); },
+			symlink(path, link, callback) { callback(enosys()); },
+			truncate(path, length, callback) { callback(enosys()); },
+			unlink(path, callback) { callback(enosys()); },
+			utimes(path, atime, mtime, callback) { callback(enosys()); },
+		};
+	}
+
+	if (!globalThis.process) {
+		globalThis.process = {
+			getuid() { return -1; },
+			getgid() { return -1; },
+			geteuid() { return -1; },
+			getegid() { return -1; },
+			getgroups() { throw enosys(); },
+			pid: -1,
+			ppid: -1,
+			umask() { throw enosys(); },
+			cwd() { throw enosys(); },
+			chdir() { throw enosys(); },
+		}
+	}
+
+	if (!globalThis.crypto) {
+		throw new Error("globalThis.crypto is not available, polyfill required (crypto.getRandomValues only)");
+	}
+
+	if (!globalThis.performance) {
+		throw new Error("globalThis.performance is not available, polyfill required (performance.now only)");
+	}
+
+	if (!globalThis.TextEncoder) {
+		throw new Error("globalThis.TextEncoder is not available, polyfill required");
+	}
+
+	if (!globalThis.TextDecoder) {
+		throw new Error("globalThis.TextDecoder is not available, polyfill required");
+	}
+
+	const encoder = new TextEncoder("utf-8");
+	const decoder = new TextDecoder("utf-8");
+
+	globalThis.Go = class {
+		constructor() {
+			this.argv = ["js"];
+			this.env = {};
+			this.exit = (code) => {
+				if (code !== 0) {
+					console.warn("exit code:", code);
+				}
+			};
+			this._exitPromise = new Promise((resolve) => {
+				this._resolveExitPromise = resolve;
+			});
+			this._pendingEvent = null;
+			this._scheduledTimeouts = new Map();
+			this._nextCallbackTimeoutID = 1;
+
+			const setInt64 = (addr, v) => {
+				this.mem.setUint32(addr + 0, v, true);
+				this.mem.setUint32(addr + 4, Math.floor(v / 4294967296), true);
+			}
+
+			const getInt64 = (addr) => {
+				const low = this.mem.getUint32(addr + 0, true);
+				const high = this.mem.getInt32(addr + 4, true);
+				return low + high * 4294967296;
+			}
+
+			const loadValue = (addr) => {
+				const f = this.mem.getFloat64(addr, true);
+				if (f === 0) {
+					return undefined;
+				}
+				if (!isNaN(f)) {
+					return f;
+				}
+
+				const id = this.mem.getUint32(addr, true);
+				return this._values[id];
+			}
+
+			const storeValue = (addr, v) => {
+				const nanHead = 0x7FF80000;
+
+				if (typeof v === "number" && v !== 0) {
+					if (isNaN(v)) {
+						this.mem.setUint32(addr + 4, nanHead, true);
+						this.mem.setUint32(addr, 0, true);
+						return;
+					}
+					this.mem.setFloat64(addr, v, true);
+					return;
+				}
+
+				if (v === undefined) {
+					this.mem.setFloat64(addr, 0, true);
+					return;
+				}
+
+				let id = this._ids.get(v);
+				if (id === undefined) {
+					id = this._idPool.pop();
+					if (id === undefined) {
+						id = this._values.length;
+					}
+					this._values[id] = v;
+					this._goRefCounts[id] = 0;
+					this._ids.set(v, id);
+				}
+				this._goRefCounts[id]++;
+				let typeFlag = 0;
+				switch (typeof v) {
+					case "object":
+						if (v !== null) {
+							typeFlag = 1;
+						}
+						break;
+					case "string":
+						typeFlag = 2;
+						break;
+					case "symbol":
+						typeFlag = 3;
+						break;
+					case "function":
+						typeFlag = 4;
+						break;
+				}
+				this.mem.setUint32(addr + 4, nanHead | typeFlag, true);
+				this.mem.setUint32(addr, id, true);
+			}
+
+			const loadSlice = (addr) => {
+				const array = getInt64(addr + 0);
+				const len = getInt64(addr + 8);
+				return new Uint8Array(this._inst.exports.mem.buffer, array, len);
+			}
+
+			const loadSliceOfValues = (addr) => {
+				const array = getInt64(addr + 0);
+				const len = getInt64(addr + 8);
+				const a = new Array(len);
+				for (let i = 0; i < len; i++) {
+					a[i] = loadValue(array + i * 8);
+				}
+				return a;
+			}
+
+			const loadString = (addr) => {
+				const saddr = getInt64(addr + 0);
+				const len = getInt64(addr + 8);
+				return decoder.decode(new DataView(this._inst.exports.mem.buffer, saddr, len));
+			}
+
+			const timeOrigin = Date.now() - performance.now();
+			this.importObject = {
+				go: {
+					// Go's SP does not change as long as no Go code is running. Some operations (e.g. calls, getters and setters)
+					// may synchronously trigger a Go event handler. This makes Go code get executed in the middle of the imported
+					// function. A goroutine can switch to a new stack if the current stack is too small (see morestack function).
+					// This changes the SP, thus we have to update the SP used by the imported function.
+
+					// func wasmExit(code int32)
+					"runtime.wasmExit": (sp) => {
+						sp >>>= 0;
+						const code = this.mem.getInt32(sp + 8, true);
+						this.exited = true;
+						delete this._inst;
+						delete this._values;
+						delete this._goRefCounts;
+						delete this._ids;
+						delete this._idPool;
+						this.exit(code);
+					},
+
+					// func wasmWrite(fd uintptr, p unsafe.Pointer, n int32)
+					"runtime.wasmWrite": (sp) => {
+						sp >>>= 0;
+						const fd = getInt64(sp + 8);
+						const p = getInt64(sp + 16);
+						const n = this.mem.getInt32(sp + 24, true);
+						fs.writeSync(fd, new Uint8Array(this._inst.exports.mem.buffer, p, n));
+					},
+
+					// func resetMemoryDataView()
+					"runtime.resetMemoryDataView": (sp) => {
+						sp >>>= 0;
+						this.mem = new DataView(this._inst.exports.mem.buffer);
+					},
+
+					// func nanotime1() int64
+					"runtime.nanotime1": (sp) => {
+						sp >>>= 0;
+						setInt64(sp + 8, (timeOrigin + performance.now()) * 1000000);
+					},
+
+					// func walltime() (sec int64, nsec int32)
+					"runtime.walltime": (sp) => {
+						sp >>>= 0;
+						const msec = (new Date).getTime();
+						setInt64(sp + 8, msec / 1000);
+						this.mem.setInt32(sp + 16, (msec % 1000) * 1000000, true);
+					},
+
+					// func scheduleTimeoutEvent(delay int64) int32
+					"runtime.scheduleTimeoutEvent": (sp) => {
+						sp >>>= 0;
+						const id = this._nextCallbackTimeoutID;
+						this._nextCallbackTimeoutID++;
+						this._scheduledTimeouts.set(id, setTimeout(
+							() => {
+								this._resume();
+								while (this._scheduledTimeouts.has(id)) {
+									// for some reason Go failed to register the timeout event, log and try again
+									// (temporary workaround for https://github.com/golang/go/issues/28975)
+									console.warn("scheduleTimeoutEvent: missed timeout event");
+									this._resume();
+								}
+							},
+							getInt64(sp + 8) + 1, // setTimeout has been seen to fire up to 1 millisecond early
+						));
+						this.mem.setInt32(sp + 16, id, true);
+					},
+
+					// func clearTimeoutEvent(id int32)
+					"runtime.clearTimeoutEvent": (sp) => {
+						sp >>>= 0;
+						const id = this.mem.getInt32(sp + 8, true);
+						clearTimeout(this._scheduledTimeouts.get(id));
+						this._scheduledTimeouts.delete(id);
+					},
+
+					// func getRandomData(r []byte)
+					"runtime.getRandomData": (sp) => {
+						sp >>>= 0;
+						crypto.getRandomValues(loadSlice(sp + 8));
+					},
+
+					// func finalizeRef(v ref)
+					"syscall/js.finalizeRef": (sp) => {
+						sp >>>= 0;
+						const id = this.mem.getUint32(sp + 8, true);
+						this._goRefCounts[id]--;
+						if (this._goRefCounts[id] === 0) {
+							const v = this._values[id];
+							this._values[id] = null;
+							this._ids.delete(v);
+							this._idPool.push(id);
+						}
+					},
+
+					// func stringVal(value string) ref
+					"syscall/js.stringVal": (sp) => {
+						sp >>>= 0;
+						storeValue(sp + 24, loadString(sp + 8));
+					},
+
+					// func valueGet(v ref, p string) ref
+					"syscall/js.valueGet": (sp) => {
+						sp >>>= 0;
+						const result = Reflect.get(loadValue(sp + 8), loadString(sp + 16));
+						sp = this._inst.exports.getsp() >>> 0; // see comment above
+						storeValue(sp + 32, result);
+					},
+
+					// func valueSet(v ref, p string, x ref)
+					"syscall/js.valueSet": (sp) => {
+						sp >>>= 0;
+						Reflect.set(loadValue(sp + 8), loadString(sp + 16), loadValue(sp + 32));
+					},
+
+					// func valueDelete(v ref, p string)
+					"syscall/js.valueDelete": (sp) => {
+						sp >>>= 0;
+						Reflect.deleteProperty(loadValue(sp + 8), loadString(sp + 16));
+					},
+
+					// func valueIndex(v ref, i int) ref
+					"syscall/js.valueIndex": (sp) => {
+						sp >>>= 0;
+						storeValue(sp + 24, Reflect.get(loadValue(sp + 8), getInt64(sp + 16)));
+					},
+
+					// valueSetIndex(v ref, i int, x ref)
+					"syscall/js.valueSetIndex": (sp) => {
+						sp >>>= 0;
+						Reflect.set(loadValue(sp + 8), getInt64(sp + 16), loadValue(sp + 24));
+					},
+
+					// func valueCall(v ref, m string, args []ref) (ref, bool)
+					"syscall/js.valueCall": (sp) => {
+						sp >>>= 0;
+						try {
+							const v = loadValue(sp + 8);
+							const m = Reflect.get(v, loadString(sp + 16));
+							const args = loadSliceOfValues(sp + 32);
+							const result = Reflect.apply(m, v, args);
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
+							storeValue(sp + 56, result);
+							this.mem.setUint8(sp + 64, 1);
+						} catch (err) {
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
+							storeValue(sp + 56, err);
+							this.mem.setUint8(sp + 64, 0);
+						}
+					},
+
+					// func valueInvoke(v ref, args []ref) (ref, bool)
+					"syscall/js.valueInvoke": (sp) => {
+						sp >>>= 0;
+						try {
+							const v = loadValue(sp + 8);
+							const args = loadSliceOfValues(sp + 16);
+							const result = Reflect.apply(v, undefined, args);
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
+							storeValue(sp + 40, result);
+							this.mem.setUint8(sp + 48, 1);
+						} catch (err) {
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
+							storeValue(sp + 40, err);
+							this.mem.setUint8(sp + 48, 0);
+						}
+					},
+
+					// func valueNew(v ref, args []ref) (ref, bool)
+					"syscall/js.valueNew": (sp) => {
+						sp >>>= 0;
+						try {
+							const v = loadValue(sp + 8);
+							const args = loadSliceOfValues(sp + 16);
+							const result = Reflect.construct(v, args);
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
+							storeValue(sp + 40, result);
+							this.mem.setUint8(sp + 48, 1);
+						} catch (err) {
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
+							storeValue(sp + 40, err);
+							this.mem.setUint8(sp + 48, 0);
+						}
+					},
+
+					// func valueLength(v ref) int
+					"syscall/js.valueLength": (sp) => {
+						sp >>>= 0;
+						setInt64(sp + 16, parseInt(loadValue(sp + 8).length));
+					},
+
+					// valuePrepareString(v ref) (ref, int)
+					"syscall/js.valuePrepareString": (sp) => {
+						sp >>>= 0;
+						const str = encoder.encode(String(loadValue(sp + 8)));
+						storeValue(sp + 16, str);
+						setInt64(sp + 24, str.length);
+					},
+
+					// valueLoadString(v ref, b []byte)
+					"syscall/js.valueLoadString": (sp) => {
+						sp >>>= 0;
+						const str = loadValue(sp + 8);
+						loadSlice(sp + 16).set(str);
+					},
+
+					// func valueInstanceOf(v ref, t ref) bool
+					"syscall/js.valueInstanceOf": (sp) => {
+						sp >>>= 0;
+						this.mem.setUint8(sp + 24, (loadValue(sp + 8) instanceof loadValue(sp + 16)) ? 1 : 0);
+					},
+
+					// func copyBytesToGo(dst []byte, src ref) (int, bool)
+					"syscall/js.copyBytesToGo": (sp) => {
+						sp >>>= 0;
+						const dst = loadSlice(sp + 8);
+						const src = loadValue(sp + 32);
+						if (!(src instanceof Uint8Array || src instanceof Uint8ClampedArray)) {
+							this.mem.setUint8(sp + 48, 0);
+							return;
+						}
+						const toCopy = src.subarray(0, dst.length);
+						dst.set(toCopy);
+						setInt64(sp + 40, toCopy.length);
+						this.mem.setUint8(sp + 48, 1);
+					},
+
+					// func copyBytesToJS(dst ref, src []byte) (int, bool)
+					"syscall/js.copyBytesToJS": (sp) => {
+						sp >>>= 0;
+						const dst = loadValue(sp + 8);
+						const src = loadSlice(sp + 16);
+						if (!(dst instanceof Uint8Array || dst instanceof Uint8ClampedArray)) {
+							this.mem.setUint8(sp + 48, 0);
+							return;
+						}
+						const toCopy = src.subarray(0, dst.length);
+						dst.set(toCopy);
+						setInt64(sp + 40, toCopy.length);
+						this.mem.setUint8(sp + 48, 1);
+					},
+
+					"debug": (value) => {
+						console.log(value);
+					},
+				}
+			};
+		}
+
+		async run(instance) {
+			if (!(instance instanceof WebAssembly.Instance)) {
+				throw new Error("Go.run: WebAssembly.Instance expected");
+			}
+			this._inst = instance;
+			this.mem = new DataView(this._inst.exports.mem.buffer);
+			this._values = [ // JS values that Go currently has references to, indexed by reference id
+				NaN,
+				0,
+				null,
+				true,
+				false,
+				globalThis,
+				this,
+			];
+			this._goRefCounts = new Array(this._values.length).fill(Infinity); // number of references that Go has to a JS value, indexed by reference id
+			this._ids = new Map([ // mapping from JS values to reference ids
+				[0, 1],
+				[null, 2],
+				[true, 3],
+				[false, 4],
+				[globalThis, 5],
+				[this, 6],
+			]);
+			this._idPool = [];   // unused ids that have been garbage collected
+			this.exited = false; // whether the Go program has exited
+
+			// Pass command line arguments and environment variables to WebAssembly by writing them to the linear memory.
+			let offset = 4096;
+
+			const strPtr = (str) => {
+				const ptr = offset;
+				const bytes = encoder.encode(str + "\0");
+				new Uint8Array(this.mem.buffer, offset, bytes.length).set(bytes);
+				offset += bytes.length;
+				if (offset % 8 !== 0) {
+					offset += 8 - (offset % 8);
+				}
+				return ptr;
+			};
+
+			const argc = this.argv.length;
+
+			const argvPtrs = [];
+			this.argv.forEach((arg) => {
+				argvPtrs.push(strPtr(arg));
+			});
+			argvPtrs.push(0);
+
+			const keys = Object.keys(this.env).sort();
+			keys.forEach((key) => {
+				argvPtrs.push(strPtr(`${key}=${this.env[key]}`));
+			});
+			argvPtrs.push(0);
+
+			const argv = offset;
+			argvPtrs.forEach((ptr) => {
+				this.mem.setUint32(offset, ptr, true);
+				this.mem.setUint32(offset + 4, 0, true);
+				offset += 8;
+			});
+
+			// The linker guarantees global data starts from at least wasmMinDataAddr.
+			// Keep in sync with cmd/link/internal/ld/data.go:wasmMinDataAddr.
+			const wasmMinDataAddr = 4096 + 8192;
+			if (offset >= wasmMinDataAddr) {
+				throw new Error("total length of command line and environment variables exceeds limit");
+			}
+
+			this._inst.exports.run(argc, argv);
+			if (this.exited) {
+				this._resolveExitPromise();
+			}
+			await this._exitPromise;
+		}
+
+		_resume() {
+			if (this.exited) {
+				throw new Error("Go program has already exited");
+			}
+			this._inst.exports.resume();
+			if (this.exited) {
+				this._resolveExitPromise();
+			}
+		}
+
+		_makeFuncWrapper(id) {
+			const go = this;
+			return function () {
+				const event = { id: id, this: this, args: arguments };
+				go._pendingEvent = event;
+				go._resume();
+				return event.result;
+			};
+		}
+	}
+})();