Implemented RET. Functions now work end to end

Author: craftybones

src/commands/call.js

@@ -25,6 +25,8 @@ class Call extends Command {
  */
  execute(regs, flags, stack, programCounter) {
  stack.push(programCounter.getNextLineNumber());
+ programCounter.setNextLineByName(this.fnName);
+ return { regs, flags };
  }
 }
 

src/commands/commandFactories.js

@@ -22,6 +22,8 @@ const PrnReg = require('./prnReg.js');
 const Push = require('./push.js');
 const Pop = require('./pop.js');
 const Func = require('./func.js');
+const Call = require('./call.js');
+const Ret = require('./ret.js');
 
 const isRegister = arg => arg.toString().match(/^[ABCD]$/i);
 const isNumericalValue = arg => arg.toString().match(/^[0-9]+$/i);
@@ -142,4 +144,17 @@ factories.func = args => {
  return new Func(args[0].toUpperCase());
 };
 
+factories.call = args => {
+ if (args.length != 1 || !isValidFunctionName(args[0]))
+ throw new InvalidInstructionException();
+
+ return new Call(args[0].toUpperCase());
+};
+
+factories.ret = args => {
+ if (args.length != 0) throw new InvalidInstructionException();
+
+ return new Ret();
+};
+
 module.exports = factories;

src/commands/ret.js

@@ -0,0 +1,11 @@
+const Command = require('./command.js');
+
+class Ret extends Command {
+ execute(regs, flags, stack, pc) {
+ let retLine = stack.pop();
+ pc.setNextLine(retLine);
+ return { regs, flags };
+ }
+}
+
+module.exports = Ret;

src/lines.js

@@ -15,7 +15,8 @@ class Lines {
  let { regs, flags, stack } = initState;
  let state = { regs, flags, halt: false };
  let lineNumbers = this.lines.map(l => l.getLineNumber());
- let programCounter = new ProgramCounter(lineNumbers);
+ console.log(this.fnTable);
+ let programCounter = new ProgramCounter(lineNumbers, this.fnTable);
  let executor = () => {
  let line = this.lines[programCounter.getCurrentLineIndex()];
  state = line.execute(state.regs, state.flags, stack, programCounter);

test/testCall.js

@@ -13,4 +13,14 @@ describe('Call execution', () => {
  call.execute(currRegs, currFlags, stack, pc);
  assert.deepEqual(['20'], stack.asArray());
  });
+
+ it('should modify the program counter to reflect the new line to jump to', () => {
+ let currFlags = { EQ: 0, NE: 0, LT: 0, GT: 0 };
+ let currRegs = { A: 0, B: 0, C: 0, D: 0 };
+ let stack = new Stack();
+ let pc = new ProgramCounter([10, 20, 30], { MUL: '30' });
+ let call = new Call('MUL');
+ call.execute(currRegs, currFlags, stack, pc);
+ assert.equal('30', pc.getNextLineNumber());
+ });
 });

test/testMachine.js

@@ -487,20 +487,21 @@ describe('Source mapping at the machine level', function() {
  });
 });
 
-describe.skip('Machine with functions', () => {
+describe('Machine with functions', () => {
  it('should execute a basic function', () => {
  const machine = new Machine();
  const program = [
  '10 START',
  '20 JMP 60',
  '30 FUNC A10',
  '40 MOV A,10',
+ '41 ADD A,20',
  '50 RET',
  '60 CALL A10',
  '70 STOP'
  ];
  machine.load(stitch(program));
  machine.execute();
- assert.deepEqual({ A: 10, B: 0, C: 0, D: 0 }, machine.getRegs());
+ assert.deepEqual({ A: 30, B: 0, C: 0, D: 0 }, machine.getRegs());
  });
 });

test/testRet.js

@@ -0,0 +1,28 @@
+const assert = require('assert');
+const Ret = require('../src/commands/ret.js');
+const Stack = require('../src/stack.js');
+const ProgramCounter = require('../src/programCounter.js');
+
+describe('Ret execution', () => {
+ it('should remove the line number to return to from the stack', () => {
+ let currFlags = { EQ: 0, NE: 0, LT: 0, GT: 0 };
+ let currRegs = { A: 0, B: 0, C: 0, D: 0 };
+ let stack = new Stack();
+ stack.push('30');
+ let pc = new ProgramCounter([10, 20, 30], { MUL: '30' });
+ let ret = new Ret('MUL');
+ ret.execute(currRegs, currFlags, stack, pc);
+ assert.deepEqual([], stack.asArray());
+ });
+
+ it('should change the program counter to reflect the line to return to', () => {
+ let currFlags = { EQ: 0, NE: 0, LT: 0, GT: 0 };
+ let currRegs = { A: 0, B: 0, C: 0, D: 0 };
+ let stack = new Stack();
+ stack.push('30');
+ let pc = new ProgramCounter([10, 20, 30], { MUL: '30' });
+ let ret = new Ret('MUL');
+ ret.execute(currRegs, currFlags, stack, pc);
+ assert.deepEqual('30', pc.getNextLineNumber());
+ });
+});