initial commit: basic interpreter

.gitignore

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+# Based on https://raw.githubusercontent.com/github/gitignore/main/Node.gitignore
+
+# Logs
+
+logs
+_.log
+npm-debug.log_
+yarn-debug.log*
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+lerna-debug.log*
+.pnpm-debug.log*
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+
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+
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+_.seed
+*.pid.lock
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+.temp
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+# TernJS port file
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+.tern-port
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+.vscode-test
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+# yarn v2
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+.yarn/cache
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+.yarn/install-state.gz
+.pnp.*
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+# IntelliJ based IDEs
+.idea
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+# Finder (MacOS) folder config
+.DS_Store
+
+test
+bun.lockb

README.md

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+# Brainfuck Interpreter
+This is a project I worked on for Hack Club [Arcade](https://hackclub.com/arcade). 
+
+## Usage
+
+<!-- (On release) The interpreter can be found on [my CDN](https://haroon.hackclub.app/cdn/bf):
+```sh
+$ curl -LO https://haroon.hackclub.app/cdn/bf
+```
+
+Once installed, y-->You can run `bun index.ts <file>.bf` to interpret a file. As of right now, there is no binary.
+
+## Testing
+```
+$ bun index.ts test.bf
+```
+
+The contents of `test.bf` is a brainfuck program that outputs Hello World.
+

index.ts

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+const memory = Array<number>(3_000).fill(0);
+
+let CI = 0 // Current Instruction
+let MA = 0 // Memory Address
+
+let stack: number[] = [];
+
+let inp = "";
+let out = "";
+
+function interpret(program: string) {
+    let fin = false;
+
+    while (!fin) {
+        console.log(CI, program.at(CI))
+        switch (program.at(CI)) {
+            case '>':
+                // Move MA to right
+                if (MA == memory.length - 1)
+                    // Expand memory if run out of space
+                    memory.push(...Array<number>(10).fill(0))
+
+                MA++
+                break;
+            
+            case '>':
+                // Move MA to left
+                if (MA > 0) MA--
+                break;
+            
+            case '+':
+                // Increment memory location at MA
+                memory[MA]++
+                break;
+
+            case '-':
+                // Decrease memory location at MA
+                memory[MA]--
+                break;
+
+            case '.':
+                // Output character with value stored at MA
+                out += String.fromCharCode(memory[MA]);
+                break;
+            
+            case ',':
+                // Read input character and store at at cell at MA
+                break;
+
+            case '[':
+                // Jump past the next ]
+                if (memory[MA]) { // If current memory value isn't non-zero, push the current instruction to the stack
+                    stack.push(CI)
+                } else {
+                    let c = 0; // Count variable, allows to find the matching bracket
+                    while (1) {
+                        CI++
+                        if (!program[CI]) break; // If this is the end of the program, break
+                        if (program[CI] == "[") c++ // If the current instruction is a [, increase the matching count
+                        else if (program[CI] == "]") { // If this is a ]
+                            if (c) c-- // If c is 0, this is a matching bracket, otherwise decrease count to help find it
+                            else break // We are now at the matching ], finish
+                        }
+                    }
+                }
+                break;
+
+            case ']':
+                // Jump to the matching [ if non-zero
+                // Set CI to last instruction value in stack
+                CI = stack.pop()! - 1;
+                break;
+
+            case undefined:
+                // End of program
+                fin = true;
+                break;
+
+            default:
+                break;
+        }
+        CI++
+    }
+    console.log(out, memory.filter(x=>x))
+}
+
+const argv = Bun.argv.slice(2);
+
+if (argv.length) {
+    const file = Bun.file(argv[0]);
+
+    file.text().then(interpret);
+}

package.json

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+{
+  "name": "brainf-interpreter",
+  "module": "index.ts",
+  "type": "module",
+  "devDependencies": {
+    "@types/bun": "latest",
+    "@types/yargs": "^17.0.32"
+  },
+  "peerDependencies": {
+    "typescript": "^5.0.0"
+  },
+  "dependencies": {
+    "yargs": "^17.7.2"
+  }
+}

test.bf

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+++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---

tsconfig.json

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+{
+  "compilerOptions": {
+    // Enable latest features
+    "lib": ["ESNext", "DOM"],
+    "target": "ESNext",
+    "module": "ESNext",
+    "moduleDetection": "force",
+    "jsx": "react-jsx",
+    "allowJs": true,
+
+    // Bundler mode
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
+    "verbatimModuleSyntax": true,
+    "noEmit": true,
+
+    // Best practices
+    "strict": true,
+    "skipLibCheck": true,
+    "noFallthroughCasesInSwitch": true,
+
+    // Some stricter flags (disabled by default)
+    "noUnusedLocals": false,
+    "noUnusedParameters": false,
+    "noPropertyAccessFromIndexSignature": false
+  }
+}