add machine logic, first draft

src/machine.rs

@@ -2,10 +2,10 @@ use std::io::{BufReader, BufWriter, Read, Write};
 
 #[derive(Debug)]
 pub enum InstructionType {
-    Plus,
-    Minus,
-    Left,
-    Right,
+    Increment,
+    Decrement,
+    Leftshift,
+    Rightshift,
     PutChar,
     GetChar,
     JumpIfZero,
@@ -14,18 +14,18 @@ pub enum InstructionType {
 
 #[derive(Debug)]
 pub struct Instruction {
-    pub ins_type: InstructionType,
+    pub itype: InstructionType,
     pub argument: usize,
 }
 
 pub struct Machine<'a> {
     ip: usize,
     mp: usize,
-    code: Vec<Instruction>,
+    buf: [u8; 1],
     memory: [u32; 50000],
+    code: Vec<Instruction>,
     input: &'a mut BufReader<Box<dyn Read>>,
     output: &'a mut BufWriter<Box<dyn Write>>,
-    buf: [u8; 1],
 }
 
 impl<'a> Machine<'a> {
@@ -33,23 +33,84 @@ impl<'a> Machine<'a> {
         Machine {
             ip: 0,
             mp: 0,
-            code,
+            buf: [0;1],
             memory: [0; 50000],
+            code,
             input,
             output,
-            buf: [0;1],
         }
     }
 
     pub fn execute(&mut self){
-        return;
+        // prevent ip from getting out of bounds
+        while self.ip < self.code.len() {
+            // get current instruction
+            let instruction = &self.code[self.ip];
+            // match type and execute
+            match instruction.itype {
+                InstructionType::Increment => {
+                    self.memory[self.mp] += instruction.argument as u32
+                }
+                InstructionType::Decrement => {
+                    self.memory[self.mp] -= instruction.argument as u32
+                }
+                InstructionType::Leftshift => {
+                    self.mp += instruction.argument
+                }
+                InstructionType::Rightshift => {
+                    self.mp -= instruction.argument
+                }
+                InstructionType::PutChar => {
+                    for _ in 0..instruction.argument {
+                        self.put_char()
+                    }
+                }
+                InstructionType::GetChar => {
+                    for _ in 0..instruction.argument {
+                        self.get_char()
+                    }
+                }
+                InstructionType::JumpIfZero => {
+                    if self.memory[self.mp] == 0 {
+                        self.ip = instruction.argument;
+                        continue;
+                    }
+                }
+                InstructionType::JumpIfNotZero => {
+                    if self.memory[self.mp] != 0 {
+                        self.ip = instruction.argument;
+                        continue;
+                    }
+                }
+            }
+        }
     }
 
-    pub fn read_char(&mut self){
-        return;
+    pub fn get_char(&mut self){
+        let byte_input = match self.input.read(&mut self.buf) {
+            Ok(byte_input) => byte_input,
+            Err(e) => panic!(e),
+        };
+
+        if byte_input != 1 {
+            panic!("input read error")
+        }
+
+        self.memory[self.mp] = self.buf[0] as u32;
     }
 
     pub fn put_char(&mut self){
-        return;
+        self.buf[0] = self.memory[self.mp] as u8;
+
+        let byte_write = match self.output.write(&self.buf) {
+            Ok(byte_write) => byte_write,
+            Err(e) => panic!(e),
+        };
+
+        if byte_write != 1 {
+            panic!("output write error")
+        }
+
+        self.output.flush();
     }
 }