Get markdown working in WASM

go.mod

@@ -19,6 +19,7 @@ require (
 	github.com/stretchr/testify v1.7.0
 	github.com/teacat/noire v1.1.0
 	github.com/wellington/go-libsass v0.9.2
+	github.com/yuin/goldmark v1.3.7
 	golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2
 )
 

go.sum

@@ -280,6 +280,8 @@ github.com/wellington/go-libsass v0.9.2 h1:6Ims04UDdBs6/CGSVK5JC8FNikR5ssrsMMKE/
 github.com/wellington/go-libsass v0.9.2/go.mod h1:mxgxgam0N0E+NAUMHLcu20Ccfc3mVpDkyrLDayqfiTs=
 github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2/go.mod h1:UETIi67q53MR2AWcXfiuqkDkRtnGDLqkBTpCHuJHxtU=
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
+github.com/yuin/goldmark v1.3.7 h1:NSaHgaeJFCtWXCBkBKXw0rhgMuJ0VoE9FB5mWldcrQ4=
+github.com/yuin/goldmark v1.3.7/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 github.com/zenazn/goji v0.9.0/go.mod h1:7S9M489iMyHBNxwZnk9/EHS098H4/F6TATF2mIxtB1Q=
 go.etcd.io/bbolt v1.3.2/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
 go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=

public/go_wasm_exec.js

@@ -0,0 +1,626 @@
+// 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.
+
+(() => {
+	// Map multiple JavaScript environments to a single common API,
+	// preferring web standards over Node.js API.
+	//
+	// Environments considered:
+	// - Browsers
+	// - Node.js
+	// - Electron
+	// - Parcel
+	// - Webpack
+
+	if (typeof global !== "undefined") {
+		// global already exists
+	} else if (typeof window !== "undefined") {
+		window.global = window;
+	} else if (typeof self !== "undefined") {
+		self.global = self;
+	} else {
+		throw new Error("cannot export Go (neither global, window nor self is defined)");
+	}
+
+	if (!global.require && typeof require !== "undefined") {
+		global.require = require;
+	}
+
+	if (!global.fs && global.require) {
+		const fs = require("fs");
+		if (typeof fs === "object" && fs !== null && Object.keys(fs).length !== 0) {
+			global.fs = fs;
+		}
+	}
+
+	const enosys = () => {
+		const err = new Error("not implemented");
+		err.code = "ENOSYS";
+		return err;
+	};
+
+	if (!global.fs) {
+		let outputBuf = "";
+		global.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 (!global.process) {
+		global.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 (!global.crypto && global.require) {
+		const nodeCrypto = require("crypto");
+		global.crypto = {
+			getRandomValues(b) {
+				nodeCrypto.randomFillSync(b);
+			},
+		};
+	}
+	if (!global.crypto) {
+		throw new Error("global.crypto is not available, polyfill required (getRandomValues only)");
+	}
+
+	if (!global.performance) {
+		global.performance = {
+			now() {
+				const [sec, nsec] = process.hrtime();
+				return sec * 1000 + nsec / 1000000;
+			},
+		};
+	}
+
+	if (!global.TextEncoder && global.require) {
+		global.TextEncoder = require("util").TextEncoder;
+	}
+	if (!global.TextEncoder) {
+		throw new Error("global.TextEncoder is not available, polyfill required");
+	}
+
+	if (!global.TextDecoder && global.require) {
+		global.TextDecoder = require("util").TextDecoder;
+	}
+	if (!global.TextDecoder) {
+		throw new Error("global.TextDecoder is not available, polyfill required");
+	}
+
+	// End of polyfills for common API.
+
+	const encoder = new TextEncoder("utf-8");
+	const decoder = new TextDecoder("utf-8");
+
+	global.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 walltime1() (sec int64, nsec int32)
+					"runtime.walltime1": (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) {
+							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) {
+							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) {
+							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,
+				global,
+				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],
+				[global, 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;
+			});
+
+			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;
+			};
+		}
+	}
+
+	if (
+		typeof module !== "undefined" &&
+		global.require &&
+		global.require.main === module &&
+		global.process &&
+		global.process.versions &&
+		!global.process.versions.electron
+	) {
+		if (process.argv.length < 3) {
+			console.error("usage: go_js_wasm_exec [wasm binary] [arguments]");
+			process.exit(1);
+		}
+
+		const go = new Go();
+		go.argv = process.argv.slice(2);
+		go.env = Object.assign({ TMPDIR: require("os").tmpdir() }, process.env);
+		go.exit = process.exit;
+		WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject).then((result) => {
+			process.on("exit", (code) => { // Node.js exits if no event handler is pending
+				if (code === 0 && !go.exited) {
+					// deadlock, make Go print error and stack traces
+					go._pendingEvent = { id: 0 };
+					go._resume();
+				}
+			});
+			return go.run(result.instance);
+		}).catch((err) => {
+			console.error(err);
+			process.exit(1);
+		});
+	}
+})();

src/parsing/parsing.go

@@ -1,8 +1,12 @@
 package parsing
 
 import (
+	"bytes"
 	"regexp"
 	"sort"
+
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/extension"
 )
 
 func StripNames(regexStr string) string {
@@ -85,3 +89,16 @@ func tokenizeBBCode(input string) []token {
 
 	return tokens
 }
+
+var md = goldmark.New(
+	goldmark.WithExtensions(extension.GFM),
+)
+
+func ParsePostInput(source string) string {
+	var buf bytes.Buffer
+	if err := md.Convert([]byte(source), &buf); err != nil {
+		panic(err)
+	}
+
+	return buf.String()
+}

src/parsing/parsing_test.go

@@ -1,6 +1,7 @@
 package parsing
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -24,3 +25,23 @@ Mix 'em: [u][/i]wow.[/i][/u]
 		assert.Equal(t, expected, ParseBBCode(bbcode))
 	})
 }
+
+func TestParsePostInput(t *testing.T) {
+	testDoc := []byte(`
+Hello, *world!*
+
+I can do **bold**, *italic*, and _underlined_ text??
+
+# Heading 1
+## Heading 2
+### Heading 3
+
+Links: [HMN](https://handmade.network)
+Images: ![this is a picture of sanic](https://i.kym-cdn.com/photos/images/newsfeed/000/722/711/ef1.jpg)
+`)
+
+	res := ParsePostInput(testDoc)
+	fmt.Println(string(res))
+
+	t.Fail()
+}

src/parsing/wasm/build.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+PUBLIC_DIR=../../../public
+
+GOOS=js GOARCH=wasm go build -o $PUBLIC_DIR/parsing.wasm
+cp "$(go env GOROOT)/misc/wasm/wasm_exec.js" $PUBLIC_DIR/go_wasm_exec.js

src/parsing/wasm/parsingmain.go

@@ -0,0 +1,16 @@
+package main
+
+import (
+	"syscall/js"
+
+	"git.handmade.network/hmn/hmn/src/parsing"
+)
+
+func main() {
+	js.Global().Set("parseMarkdown", js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+		return parsing.ParsePostInput(args[0].String())
+	}))
+
+	var done chan bool
+	<-done // block forever
+}

src/templates/src/editor.html

@@ -2,8 +2,16 @@
 
 {{ define "extrahead" }}
     <link rel="stylesheet" href="{{ static "editor.css" }}" />
-    <script type="text/javascript" src="{{ static "util.js" }}"></script>
+    <script src="{{ static "util.js" }}"></script>
-    <script type="text/javascript" src="{{ static "editor.js" }}"></script>
+    <script src="{{ static "editor.js" }}"></script>
+
+    <script src="{{ static "go_wasm_exec.js" }}"></script>
+    <script>
+        const go = new Go();
+        WebAssembly.instantiateStreaming(fetch("{{ static "parsing.wasm" }}"), go.importObject).then(result => {
+            go.run(result.instance);
+        });
+    </script>
 {{ end }}
 
 {{ define "content" }}
@@ -34,13 +42,17 @@
             <input type="button" id="youtube" value="youtube" />
         </div>
         */}}
-        <textarea class="w-100 minw-100 mw-100 h5 minh-5" name="body">{{ .PostBody }}</textarea>
+        <textarea id="editor" class="w-100 minw-100 mw-100 h5 minh-5" name="body">{{ .PostBody }}</textarea>
 
         <div class="flex flex-row-reverse justify-start mt2">
             <input type="submit" class="button ml2" name="submit" value="{{ .SubmitLabel }}" />
             <input type="submit" class="button ml2" name="preview" value="{{ .PreviewLabel }}" />
         </div>
 
+        <div class="post post-preview mv3">
+            <div id="preview" class="body contents"></div>
+        </div>
+
         {{/*
         {% if are_editing %}
             <span class="editreason">
@@ -91,4 +103,14 @@
         */}}
     </form>
 </div>
+
+<script>
+    const tf = document.querySelector('#editor');
+    const preview = document.querySelector('#preview');
+
+    tf.addEventListener('input', () => {
+        const previewHtml = parseMarkdown(tf.value);
+        preview.innerHTML = previewHtml;
+    })
+</script>
 {{ end }}