Add CLI runner and sample Tabloid programs

README.md

@@ -87,6 +87,16 @@ The interpreter uses a tree-walk evaluator on the syntax tree to execute a progr
 
 Please don't.
 
+## Running programs locally
+
+If you just can't resist, there's a tiny CLI runner in `run-tabloid.js` that executes Tabloid source files with Node.js. Point it at any `.tabloid` file (see `examples/` for the Fibonacci and Mandelbrot demos we added) and it'll shout the output just like the website does.
+
+```
+node run-tabloid.js examples/fib.tabloid
+```
+
+The script wires `YOU WON'T WANT TO MISS` to stdout (always uppercased with a trailing `!`) and `LATEST NEWS ON` to a blocking stdin prompt, so you can pipe input or type it interactively.
+
 ## Limitations
 
 Tabloid's syntax has some (soft) limitations for now, because I had ~8 hours to finish it. Here are some of them:

examples/calculator.tabloid

@@ -0,0 +1,38 @@
+YOU WON'T WANT TO MISS 'TABLOID FOUR FUNCTION CALCULATOR'
+
+DISCOVER HOW TO toNumber WITH raw
+RUMOR HAS IT
+    SHOCKING DEVELOPMENT raw TIMES 1
+END OF STORY
+
+DISCOVER HOW TO compute WITH left, right, op
+RUMOR HAS IT
+    WHAT IF op IS ACTUALLY 'PLUS' RUMOR HAS IT
+        SHOCKING DEVELOPMENT left PLUS right
+    END OF STORY
+    LIES! WHAT IF op IS ACTUALLY 'MINUS' RUMOR HAS IT
+        SHOCKING DEVELOPMENT left MINUS right
+    END OF STORY
+    LIES! WHAT IF op IS ACTUALLY 'TIMES' RUMOR HAS IT
+        SHOCKING DEVELOPMENT left TIMES right
+    END OF STORY
+    LIES! WHAT IF op IS ACTUALLY 'DIVIDED BY' RUMOR HAS IT
+        SHOCKING DEVELOPMENT left DIVIDED BY right
+    END OF STORY
+    LIES!
+        SHOCKING DEVELOPMENT 'UNSUPPORTED OPERATOR'
+END OF STORY
+
+EXPERTS CLAIM firstInput TO BE LATEST NEWS ON 'Enter the first number:'
+EXPERTS CLAIM secondInput TO BE LATEST NEWS ON 'Enter the second number:'
+EXPERTS CLAIM opInput TO BE LATEST NEWS ON 'Type PLUS, MINUS, TIMES, or DIVIDED BY:'
+
+EXPERTS CLAIM firstNumber TO BE toNumber OF firstInput
+EXPERTS CLAIM secondNumber TO BE toNumber OF secondInput
+
+EXPERTS CLAIM result TO BE compute OF firstNumber, secondNumber, opInput
+
+YOU WON'T WANT TO MISS 'Result'
+YOU WON'T WANT TO MISS result
+
+PLEASE LIKE AND SUBSCRIBE

examples/fib.tabloid

@@ -0,0 +1,16 @@
+DISCOVER HOW TO fibonacci WITH a, b, n
+RUMOR HAS IT
+    WHAT IF n SMALLER THAN 1
+        SHOCKING DEVELOPMENT b
+    LIES! RUMOR HAS IT
+        YOU WON'T WANT TO MISS b
+        SHOCKING DEVELOPMENT
+            fibonacci OF b, a PLUS b, n MINUS 1
+    END OF STORY
+END OF STORY
+
+EXPERTS CLAIM limit TO BE 10
+YOU WON'T WANT TO MISS 'First 10 Fibonacci numbers'
+EXPERTS CLAIM nothing TO BE fibonacci OF 0, 1, limit
+
+PLEASE LIKE AND SUBSCRIBE

examples/mandelbrot.tabloid

@@ -0,0 +1,77 @@
+YOU WON'T WANT TO MISS 'TABLOID MANDELBROT SET'
+
+DISCOVER HOW TO mandelbrot WITH cx, cy, zx, zy, iteration, maxIterations
+RUMOR HAS IT
+    EXPERTS CLAIM lastIteration TO BE maxIterations MINUS 1
+    WHAT IF iteration BEATS lastIteration
+        SHOCKING DEVELOPMENT TOTALLY RIGHT
+    LIES! RUMOR HAS IT
+        EXPERTS CLAIM zxSquared TO BE zx TIMES zx
+        EXPERTS CLAIM zySquared TO BE zy TIMES zy
+        EXPERTS CLAIM magnitude TO BE zxSquared PLUS zySquared
+        WHAT IF magnitude BEATS 4
+            SHOCKING DEVELOPMENT COMPLETELY WRONG
+        LIES! RUMOR HAS IT
+            EXPERTS CLAIM difference TO BE zxSquared MINUS zySquared
+            EXPERTS CLAIM product TO BE zx TIMES zy
+            EXPERTS CLAIM doubleProduct TO BE 2 TIMES product
+            EXPERTS CLAIM nextZx TO BE difference PLUS cx
+            EXPERTS CLAIM nextZy TO BE doubleProduct PLUS cy
+            SHOCKING DEVELOPMENT
+                mandelbrot OF cx, cy, nextZx, nextZy, iteration PLUS 1, maxIterations
+        END OF STORY
+    END OF STORY
+END OF STORY
+
+DISCOVER HOW TO pixel WITH inside
+RUMOR HAS IT
+    WHAT IF inside
+        SHOCKING DEVELOPMENT '#'
+    LIES!
+        SHOCKING DEVELOPMENT '.'
+END OF STORY
+
+DISCOVER HOW TO rowPixels WITH row, col, maxCols, maxRows, minX, maxX, minY, maxY, maxIterations
+RUMOR HAS IT
+    EXPERTS CLAIM lastCol TO BE maxCols MINUS 1
+    WHAT IF col BEATS lastCol
+        SHOCKING DEVELOPMENT ''
+    LIES! RUMOR HAS IT
+        EXPERTS CLAIM xRange TO BE maxX MINUS minX
+        EXPERTS CLAIM yRange TO BE maxY MINUS minY
+        EXPERTS CLAIM colRatio TO BE col DIVIDED BY maxCols
+        EXPERTS CLAIM rowRatio TO BE row DIVIDED BY maxRows
+        EXPERTS CLAIM xOffset TO BE xRange TIMES colRatio
+        EXPERTS CLAIM yOffset TO BE yRange TIMES rowRatio
+        EXPERTS CLAIM xCoord TO BE minX PLUS xOffset
+        EXPERTS CLAIM yCoord TO BE minY PLUS yOffset
+        EXPERTS CLAIM inside TO BE mandelbrot OF xCoord, yCoord, 0, 0, 0, maxIterations
+        EXPERTS CLAIM char TO BE pixel OF inside
+        EXPERTS CLAIM remainder TO BE rowPixels OF row, col PLUS 1, maxCols, maxRows, minX, maxX, minY, maxY, maxIterations
+        SHOCKING DEVELOPMENT char PLUS remainder
+    END OF STORY
+END OF STORY
+
+DISCOVER HOW TO renderRows WITH row, maxRows, maxCols, minX, maxX, minY, maxY, maxIterations
+RUMOR HAS IT
+    EXPERTS CLAIM lastRow TO BE maxRows MINUS 1
+    WHAT IF row BEATS lastRow
+        SHOCKING DEVELOPMENT TOTALLY RIGHT
+    LIES! RUMOR HAS IT
+        EXPERTS CLAIM pixels TO BE rowPixels OF row, 0, maxCols, maxRows, minX, maxX, minY, maxY, maxIterations
+        YOU WON'T WANT TO MISS pixels
+        SHOCKING DEVELOPMENT renderRows OF row PLUS 1, maxRows, maxCols, minX, maxX, minY, maxY, maxIterations
+    END OF STORY
+END OF STORY
+
+EXPERTS CLAIM maxCols TO BE 60
+EXPERTS CLAIM maxRows TO BE 24
+EXPERTS CLAIM minX TO BE -2.5
+EXPERTS CLAIM maxX TO BE 1
+EXPERTS CLAIM minY TO BE -1
+EXPERTS CLAIM maxY TO BE 1
+EXPERTS CLAIM maxIterations TO BE 30
+
+EXPERTS CLAIM done TO BE renderRows OF 0, maxRows, maxCols, minX, maxX, minY, maxY, maxIterations
+
+PLEASE LIKE AND SUBSCRIBE

run-tabloid.js

@@ -0,0 +1,98 @@
+#!/usr/bin/env node
+
+/**
+ * Minimal CLI runner for Tabloid programs.
+ *
+ * Usage:
+ *   node run-tabloid.js path/to/program.tabl
+ *
+ * The runner wires Tabloid's `YOU WON'T WANT TO MISS` output to stdout,
+ * and `LATEST NEWS ON` prompts to stdin/stdout synchronously.
+ */
+
+const fs = require('fs');
+const path = require('path');
+const vm = require('vm');
+
+function usageAndExit() {
+    console.error('Usage: node run-tabloid.js <path-to-program>');
+    process.exit(1);
+}
+
+if (process.argv.length < 3) {
+    usageAndExit();
+}
+
+const progPath = path.resolve(process.argv[2]);
+if (!fs.existsSync(progPath) || !fs.statSync(progPath).isFile()) {
+    console.error(`Program not found: ${progPath}`);
+    process.exit(1);
+}
+
+const langSource = fs.readFileSync(path.join(__dirname, 'static/js/lang.js'), 'utf8');
+const programSource = fs.readFileSync(progPath, 'utf8');
+
+const sandbox = {};
+vm.createContext(sandbox);
+vm.runInContext(
+    `${langSource}
+    this.tokenize = tokenize;
+    this.Parser = Parser;
+    this.Environment = Environment;
+`,
+    sandbox
+);
+
+function createLineReader() {
+    let buffer = '';
+    return function readLine(promptText) {
+        if (promptText) {
+            process.stdout.write(promptText);
+            if (!promptText.trim().endsWith(':')) {
+                process.stdout.write(' ');
+            }
+        }
+        while (true) {
+            const newlineIndex = buffer.indexOf('\n');
+            if (newlineIndex >= 0) {
+                const line = buffer.slice(0, newlineIndex);
+                buffer = buffer.slice(newlineIndex + 1);
+                return line.replace(/\r$/, '');
+            }
+            const chunk = Buffer.alloc(1024);
+            const bytesRead = fs.readSync(0, chunk, 0, chunk.length, null);
+            if (bytesRead === 0) {
+                const remaining = buffer;
+                buffer = '';
+                return remaining;
+            }
+            buffer += chunk.toString('utf8', 0, bytesRead);
+        }
+    };
+}
+
+const readLine = createLineReader();
+
+const env = new sandbox.Environment({
+    print: s => {
+        let out = s;
+        if (out === true) out = 'TOTALLY RIGHT';
+        if (out === false) out = 'COMPLETELY WRONG';
+        process.stdout.write(out.toString().toUpperCase() + '!\n');
+    },
+    input: promptText => {
+        let message = promptText;
+        if (message === true) message = 'TOTALLY RIGHT';
+        if (message === false) message = 'COMPLETELY WRONG';
+        return readLine(message.toString());
+    },
+});
+
+try {
+    const tokens = sandbox.tokenize(programSource);
+    const nodes = new sandbox.Parser(tokens).parse();
+    env.run(nodes);
+} catch (err) {
+    console.error(err instanceof Error ? err.stack || err.message : err);
+    process.exit(1);
+}