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| 1 | +<!DOCTYPE html> |
| 2 | +<html lang="en"> |
| 3 | +<head> |
| 4 | + <meta charset="UTF-8"> |
| 5 | + <meta http-equiv="X-UA-Compatible" content="IE=edge"> |
| 6 | + <meta name="viewport" content="width=device-width, initial-scale=1.0"> |
| 7 | + <meta name="author" content="Katie Bell"> |
| 8 | + <meta name="description" content="Simple REPL for Python WASM"> |
| 9 | + <title>wasm-python terminal</title> |
| 10 | + <link rel=" stylesheet" href=" https://unpkg.com/[email protected]/css/xterm.css" crossorigin/> |
| 11 | + <style> |
| 12 | + body { |
| 13 | + font-family: arial; |
| 14 | + max-width: 800px; |
| 15 | + margin: 0 auto |
| 16 | + } |
| 17 | + #code { |
| 18 | + width: 100%; |
| 19 | + height: 180px; |
| 20 | + } |
| 21 | + #info { |
| 22 | + padding-top: 20px; |
| 23 | + } |
| 24 | + .button-container { |
| 25 | + display: flex; |
| 26 | + justify-content: end; |
| 27 | + height: 50px; |
| 28 | + align-items: center; |
| 29 | + gap: 10px; |
| 30 | + } |
| 31 | + button { |
| 32 | + padding: 6px 18px; |
| 33 | + } |
| 34 | + </style> |
| 35 | + <script src=" https://unpkg.com/[email protected]/lib/xterm.js" crossorigin></script> |
| 36 | + <script type="module"> |
| 37 | +class WorkerManager { |
| 38 | + constructor(workerURL, standardIO, readyCallBack) { |
| 39 | + this.workerURL = workerURL |
| 40 | + this.worker = null |
| 41 | + this.standardIO = standardIO |
| 42 | + this.readyCallBack = readyCallBack |
| 43 | + |
| 44 | + this.initialiseWorker() |
| 45 | + } |
| 46 | + |
| 47 | + async initialiseWorker() { |
| 48 | + if (!this.worker) { |
| 49 | + this.worker = new Worker(this.workerURL) |
| 50 | + this.worker.addEventListener('message', this.handleMessageFromWorker) |
| 51 | + } |
| 52 | + } |
| 53 | + |
| 54 | + async run(options) { |
| 55 | + this.worker.postMessage({ |
| 56 | + type: 'run', |
| 57 | + args: options.args || [], |
| 58 | + files: options.files || {} |
| 59 | + }) |
| 60 | + } |
| 61 | + |
| 62 | + handleStdinData(inputValue) { |
| 63 | + if (this.stdinbuffer && this.stdinbufferInt) { |
| 64 | + let startingIndex = 1 |
| 65 | + if (this.stdinbufferInt[0] > 0) { |
| 66 | + startingIndex = this.stdinbufferInt[0] |
| 67 | + } |
| 68 | + const data = new TextEncoder().encode(inputValue) |
| 69 | + data.forEach((value, index) => { |
| 70 | + this.stdinbufferInt[startingIndex + index] = value |
| 71 | + }) |
| 72 | + |
| 73 | + this.stdinbufferInt[0] = startingIndex + data.length - 1 |
| 74 | + Atomics.notify(this.stdinbufferInt, 0, 1) |
| 75 | + } |
| 76 | + } |
| 77 | + |
| 78 | + handleMessageFromWorker = (event) => { |
| 79 | + const type = event.data.type |
| 80 | + if (type === 'ready') { |
| 81 | + this.readyCallBack() |
| 82 | + } else if (type === 'stdout') { |
| 83 | + this.standardIO.stdout(event.data.stdout) |
| 84 | + } else if (type === 'stderr') { |
| 85 | + this.standardIO.stderr(event.data.stderr) |
| 86 | + } else if (type === 'stdin') { |
| 87 | + // Leave it to the terminal to decide whether to chunk it into lines |
| 88 | + // or send characters depending on the use case. |
| 89 | + this.stdinbuffer = event.data.buffer |
| 90 | + this.stdinbufferInt = new Int32Array(this.stdinbuffer) |
| 91 | + this.standardIO.stdin().then((inputValue) => { |
| 92 | + this.handleStdinData(inputValue) |
| 93 | + }) |
| 94 | + } else if (type === 'finished') { |
| 95 | + this.standardIO.stderr(`Exited with status: ${event.data.returnCode}\r\n`) |
| 96 | + } |
| 97 | + } |
| 98 | +} |
| 99 | + |
| 100 | +class WasmTerminal { |
| 101 | + |
| 102 | + constructor() { |
| 103 | + this.input = '' |
| 104 | + this.resolveInput = null |
| 105 | + this.activeInput = false |
| 106 | + this.inputStartCursor = null |
| 107 | + |
| 108 | + this.xterm = new Terminal( |
| 109 | + { scrollback: 10000, fontSize: 14, theme: { background: '#1a1c1f' }, cols: 100} |
| 110 | + ); |
| 111 | + |
| 112 | + this.xterm.onKey((keyEvent) => { |
| 113 | + // Fix for iOS Keyboard Jumping on space |
| 114 | + if (keyEvent.key === " ") { |
| 115 | + keyEvent.domEvent.preventDefault(); |
| 116 | + } |
| 117 | + }); |
| 118 | + |
| 119 | + this.xterm.onData(this.handleTermData) |
| 120 | + } |
| 121 | + |
| 122 | + open(container) { |
| 123 | + this.xterm.open(container); |
| 124 | + } |
| 125 | + |
| 126 | + handleReadComplete(lastChar) { |
| 127 | + this.resolveInput(this.input + lastChar) |
| 128 | + this.activeInput = false |
| 129 | + } |
| 130 | + |
| 131 | + handleTermData = (data) => { |
| 132 | + if (!this.activeInput) { |
| 133 | + return |
| 134 | + } |
| 135 | + const ord = data.charCodeAt(0); |
| 136 | + let ofs; |
| 137 | + |
| 138 | + // TODO: Handle ANSI escape sequences |
| 139 | + if (ord === 0x1b) { |
| 140 | + // Handle special characters |
| 141 | + } else if (ord < 32 || ord === 0x7f) { |
| 142 | + switch (data) { |
| 143 | + case "\r": // ENTER |
| 144 | + case "\x0a": // CTRL+J |
| 145 | + case "\x0d": // CTRL+M |
| 146 | + this.xterm.write('\r\n'); |
| 147 | + this.handleReadComplete('\n'); |
| 148 | + break; |
| 149 | + case "\x7F": // BACKSPACE |
| 150 | + case "\x08": // CTRL+H |
| 151 | + case "\x04": // CTRL+D |
| 152 | + this.handleCursorErase(true); |
| 153 | + break; |
| 154 | + } |
| 155 | + } else { |
| 156 | + this.handleCursorInsert(data); |
| 157 | + } |
| 158 | + } |
| 159 | + |
| 160 | + handleCursorInsert(data) { |
| 161 | + this.input += data; |
| 162 | + this.xterm.write(data) |
| 163 | + } |
| 164 | + |
| 165 | + handleCursorErase() { |
| 166 | + // Don't delete past the start of input |
| 167 | + if (this.xterm.buffer.active.cursorX <= this.inputStartCursor) { |
| 168 | + return |
| 169 | + } |
| 170 | + this.input = this.input.slice(0, -1) |
| 171 | + this.xterm.write('\x1B[D') |
| 172 | + this.xterm.write('\x1B[P') |
| 173 | + } |
| 174 | + |
| 175 | + prompt = async () => { |
| 176 | + this.activeInput = true |
| 177 | + // Hack to allow stdout/stderr to finish before we figure out where input starts |
| 178 | + setTimeout(() => {this.inputStartCursor = this.xterm.buffer.active.cursorX}, 1) |
| 179 | + return new Promise((resolve, reject) => { |
| 180 | + this.resolveInput = (value) => { |
| 181 | + this.input = '' |
| 182 | + resolve(value) |
| 183 | + } |
| 184 | + }) |
| 185 | + } |
| 186 | + |
| 187 | + clear() { |
| 188 | + this.xterm.clear(); |
| 189 | + } |
| 190 | + |
| 191 | + print(message) { |
| 192 | + const normInput = message.replace(/[\r\n]+/g, "\n").replace(/\n/g, "\r\n"); |
| 193 | + this.xterm.write(normInput); |
| 194 | + } |
| 195 | +} |
| 196 | + |
| 197 | +const replButton = document.getElementById('repl') |
| 198 | +const clearButton = document.getElementById('clear') |
| 199 | + |
| 200 | +window.onload = () => { |
| 201 | + const terminal = new WasmTerminal() |
| 202 | + terminal.open(document.getElementById('terminal')) |
| 203 | + |
| 204 | + const stdio = { |
| 205 | + stdout: (s) => { terminal.print(s) }, |
| 206 | + stderr: (s) => { terminal.print(s) }, |
| 207 | + stdin: async () => { |
| 208 | + return await terminal.prompt() |
| 209 | + } |
| 210 | + } |
| 211 | + |
| 212 | + replButton.addEventListener('click', (e) => { |
| 213 | + // Need to use "-i -" to force interactive mode. |
| 214 | + // Looks like isatty always returns false in emscripten |
| 215 | + pythonWorkerManager.run({args: ['-i', '-'], files: {}}) |
| 216 | + }) |
| 217 | + |
| 218 | + clearButton.addEventListener('click', (e) => { |
| 219 | + terminal.clear() |
| 220 | + }) |
| 221 | + |
| 222 | + const readyCallback = () => { |
| 223 | + replButton.removeAttribute('disabled') |
| 224 | + clearButton.removeAttribute('disabled') |
| 225 | + } |
| 226 | + |
| 227 | + const pythonWorkerManager = new WorkerManager('./python.worker.js', stdio, readyCallback) |
| 228 | +} |
| 229 | + </script> |
| 230 | +</head> |
| 231 | +<body> |
| 232 | + <h1>Simple REPL for Python WASM</h1> |
| 233 | + <div id="terminal"></div> |
| 234 | + <div class="button-container"> |
| 235 | + <button id="repl" disabled>Start REPL</button> |
| 236 | + <button id="clear" disabled>Clear</button> |
| 237 | + </div> |
| 238 | + <div id="info"> |
| 239 | + The simple REPL provides a limited Python experience in the browser. |
| 240 | + <a href="https://github.com/python/cpython/blob/main/Tools/wasm/README.md"> |
| 241 | + Tools/wasm/README.md</a> contains a list of known limitations and |
| 242 | + issues. Networking, subprocesses, and threading are not available. |
| 243 | + </div> |
| 244 | +</body> |
| 245 | +</html> |
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