name changes

.gitignore

@@ -1 +1,2 @@
 /target
+inp.txt

inp.txt

@@ -1,3 +0,0 @@
-pHello pWorld! 
-a15-16 s19-4 m3-3 d9-3
-

src/eval.rs

@@ -1,4 +1,4 @@
-pub fn do_math(arguments: &str, operator: char) -> u32 {
+pub fn do_math(arguments: String, operator: char) -> u32 {
     let split_args = arguments.split("-").collect::<Vec<&str>>();
 
     let num1: u32 = match split_args[0].parse() {

src/main.rs

@@ -2,12 +2,14 @@ use std::fs;
 use std::env;
 use std::fmt;
 use std::usize;
+use std::collections::HashMap;
 
 mod eval;
 
 struct Program {
     data: Vec<String>,
-    pc: usize
+    pc: usize,
+    vars: HashMap<char, char>
 }
 
 impl Program {
@@ -22,19 +24,42 @@ impl Program {
                 op_list.push(new_op.to_owned());
             }
         }
-        return Program{ data: op_list, pc: 0 };
+
+        return Program{ data: op_list, pc: 0, vars: HashMap::new() };
     }
 
-    fn eval(&self, instruction: &String) {
+    fn args_or_vars<'a>(&self, arguments: &'a str) -> String {
+        let mut deconstructed: Vec<char> = arguments.chars().collect();
+
+        for (index, char) in arguments.chars().enumerate() {
+            let value = self.vars.get(&char);
+
+            match value {
+                Some(content) => deconstructed[index] = *content,
+                None => {}
+            }
+        }
+
+        deconstructed.into_iter().collect()
+    }
+
+    fn add_var(&mut self, arguments: &str) {
+        let argument_vec: Vec<char> = arguments.chars().collect();
+
+        self.vars.insert(argument_vec[0], argument_vec[1]);
+    }
+
+    fn parse(&mut self, instruction: &String) {
         let opcode = instruction.chars().collect::<Vec<char>>()[0];
         let arguments = &instruction[1..];
 
         match opcode {
-            'p' => println!("{}", arguments),
-            'a' => println!("{}", eval::do_math(arguments, '+')),
-            's' => println!("{}", eval::do_math(arguments, '-')),
-            'm' => println!("{}", eval::do_math(arguments, '*')),
-            'd' => println!("{}", eval::do_math(arguments, '/')),
+            'p' => println!("{}", self.args_or_vars(arguments)),
+            'a' => println!("{}", eval::do_math(self.args_or_vars(arguments), '+')),
+            's' => println!("{}", eval::do_math(self.args_or_vars(arguments), '-')),
+            'm' => println!("{}", eval::do_math(self.args_or_vars(arguments), '*')),
+            'd' => println!("{}", eval::do_math(self.args_or_vars(arguments), '/')),
+            'l' => self.add_var(arguments),
             _ => panic!("SyntaxError at opcode {}!", self.pc)
         }
     }
@@ -42,9 +67,9 @@ impl Program {
     fn run(&mut self) {
         println!("{}", self);
         while self.pc < self.data.len() {
-            let instruction = &self.data[self.pc];
+            let instruction = self.data[self.pc].to_owned();
 
-            self.eval(instruction);
+            self.parse(&instruction);
 
             self.pc = self.pc + 1;
         }
@@ -58,10 +83,9 @@ impl fmt::Display for Program {
 }
 
 fn main() {
-
     let args: Vec<String> = env::args().collect();
     if args.len() == 1 {
-        panic!("You must provide an argument!");
+        panic!("You must provide a filename!");
     }
 
     let filename = &args[1];