From 69287beabd8beb0616737a3bb000b9cee2ba1a6f Mon Sep 17 00:00:00 2001
From: huwenchao <huwenchao@cryptape.com>
Date: Mon, 6 Jan 2020 20:52:20 +0800
Subject: [PATCH] feat: add brainfuck example written in class

---
 README.md                             |   5 +-
 examples/brainfuck_class/brainfuck.ts | 153 ++++++++++++++++++++++++++
 examples/brainfuck_class/test.ts      |  14 +++
 3 files changed, 170 insertions(+), 2 deletions(-)
 create mode 100644 examples/brainfuck_class/brainfuck.ts
 create mode 100644 examples/brainfuck_class/test.ts

diff --git a/README.md b/README.md
index 9c13166..7df2516 100644
--- a/README.md
+++ b/README.md
@@ -18,8 +18,9 @@ Then install minits:
 
 ```
 $ git clone https://github.com/cryptape/minits
-$ npm install
-$ npm run build
+$ cd minits
+$ yarn
+$ yarn run build
 ```
 
 # Writing and Compiling a TypeScript Program
diff --git a/examples/brainfuck_class/brainfuck.ts b/examples/brainfuck_class/brainfuck.ts
new file mode 100644
index 0000000..a8f6991
--- /dev/null
+++ b/examples/brainfuck_class/brainfuck.ts
@@ -0,0 +1,153 @@
+// $ node build/main/index.js build examples/brainfuck_class/brainfuck.ts -o brainfuck.ll
+// $ clang brainfuck.ll -o brainfuck
+//
+// $ ./brainfuck "++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>."
+
+const enum Opcode {
+    SHR = '>',
+    SHL = '<',
+    ADD = '+',
+    SUB = '-',
+    PUTCHAR = '.',
+    GETCHAR = ',',
+    LB = '[',
+    RB = ']',
+}
+
+export class BrainfuckInterpreter {
+    code: string;
+    pc: number;
+    ps: number;
+
+    constructor(code: string) {
+        this.code = code;
+        this.pc = 0;
+        this.ps = 0;
+    }
+
+    reset() {
+        this.pc = 0;
+        this.ps = 0;
+    }
+
+    uint8(n: number): number {
+        if (n > 0xff) {
+            return this.uint8(n - 256);
+        }
+        if (n < 0x00) {
+            return this.uint8(n + 256);
+        }
+        return n
+    }
+
+    run(): number {
+        this.reset();
+        let stack = [
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+        ];
+        // run
+        for (; this.pc < this.code.length;) {
+            let op = this.code[this.pc];
+            if (op === Opcode.SHR) {
+                this.ps += 1;
+                this.pc += 1;
+                continue
+            }
+            if (op === Opcode.SHL) {
+                this.ps -= 1;
+                this.pc += 1;
+                continue
+            }
+            if (op === Opcode.ADD) {
+                stack[this.ps] = this.uint8(stack[this.ps] + 1);
+                this.pc += 1;
+                continue
+            }
+            if (op === Opcode.SUB) {
+                stack[this.ps] = this.uint8(stack[this.ps] - 1);
+                this.pc += 1;
+                continue
+            }
+            if (op === Opcode.PUTCHAR) {
+                this.putchar(stack[this.ps]);
+                this.pc += 1;
+                continue
+            }
+            if (op === Opcode.GETCHAR) {
+                console.log('GETCHAR is disabled');
+                return 1;
+            }
+
+
+            if (op === Opcode.LB) {
+                if (stack[this.ps] != 0x00) {
+                    this.pc += 1;
+                    continue
+                }
+                let n = 1;
+                for (; n !== 0;) {
+                    this.pc += 1;
+                    if (this.code[this.pc] === Opcode.LB) {
+                        n += 1;
+                        continue
+                    }
+                    if (this.code[this.pc] === Opcode.RB) {
+                        n -= 1;
+                        continue
+                    }
+                }
+                this.pc += 1;
+                continue
+            }
+            if (op === Opcode.RB) {
+                if (stack[this.ps] === 0x00) {
+                    this.pc += 1;
+                    continue
+                }
+                let n = 1;
+                for (; n !== 0;) {
+                    this.pc -= 1;
+                    if (this.code[this.pc] === Opcode.RB) {
+                        n += 1;
+                        continue
+                    }
+                    if (this.code[this.pc] === Opcode.LB) {
+                        n -= 1;
+                        continue
+                    }
+                }
+                this.pc += 1;
+                continue
+            }
+        }
+        return 0;
+    }
+
+    putchar(n: number) {
+        console.log('%c', n);
+    }
+}
+
+export function main(argc: number, argv: string[]): number {
+    if (argc !== 2) {
+        return 1;
+    }
+    let bfi = new BrainfuckInterpreter(argv[1]);
+    let status_code = bfi.run();
+    return status_code;
+}
diff --git a/examples/brainfuck_class/test.ts b/examples/brainfuck_class/test.ts
new file mode 100644
index 0000000..9a3399c
--- /dev/null
+++ b/examples/brainfuck_class/test.ts
@@ -0,0 +1,14 @@
+// use ts-node to run the file directly for devlopment and test.
+// ts-node examples/brainfuck_class/test.ts
+import { BrainfuckInterpreter } from './brainfuck';
+
+BrainfuckInterpreter.prototype.putchar = (n: number) => {
+    process.stdout.write(String.fromCharCode(n));
+}
+let code = '++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++.';
+console.log(`code: ${code}`);
+console.log('\n---------- start ----------');
+let bfi = new BrainfuckInterpreter(code);
+let status_code = bfi.run();
+console.log('----------  end  ----------\n');
+console.log(`status_code: ${status_code}`);