Add support for functions and variables in if statements

Cargo.lock

@@ -1,5 +1,40 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+[[package]]
+name = "aho-corasick"
+version = "0.7.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7404febffaa47dac81aa44dba71523c9d069b1bdc50a77db41195149e17f68e5"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "memchr"
+version = "2.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ee1c47aaa256ecabcaea351eae4a9b01ef39ed810004e298d2511ed284b1525"
+
+[[package]]
+name = "regex"
+version = "1.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "957056ecddbeba1b26965114e191d2e8589ce74db242b6ea25fc4062427a5c19"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24d5f089152e60f62d28b835fbff2cd2e8dc0baf1ac13343bef92ab7eed84548"
+
 [[package]]
 name = "sandwich"
 version = "0.1.0"
+dependencies = [
+ "regex",
+]

Cargo.toml

@@ -7,3 +7,4 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+regex = "1"

src/main.rs

@@ -4,6 +4,8 @@ use std::fmt;
 use std::fs;
 use std::usize;
 
+use regex::Regex;
+
 mod eval;
 
 struct Program {
@@ -198,21 +200,55 @@ impl Program {
         }
     }
 
+    fn handle_if_statement(&mut self, arguments: String) {
+        let argument_vec: Vec<&str> = arguments.split(":").collect();
+
+        let condition = argument_vec[0];
+        let success = argument_vec[1];
+        let failure = argument_vec[2];
+
+
+        let re = Regex::new(r"(?P<num1>\d+)(?P<operator>==|!=|>|<|>=|<=)(?P<num2>\d+)").unwrap();
+        let caps = re.captures(condition).unwrap();
+        let num1 = &caps["num1"];
+        let operator = &caps["operator"];
+        let num2 = &caps["num2"];
+
+        let meets_condition: bool;
+
+        match operator {
+            "==" => meets_condition = num1 == num2,
+            "!=" => meets_condition = num1 != num2,
+            ">" => meets_condition = num1 > num2,
+            "<" => meets_condition = num1 < num2,
+            ">=" => meets_condition = num1 >= num2,
+            "<=" => meets_condition = num1 <= num2,
+            _ => panic!("SyntaxError: Unknown operator at opcode {}: {}", self.pc, operator)
+        };
+
+        if meets_condition {
+            self.parse(&(success.to_string()));
+        } else {
+            self.parse(&(failure.to_string()));
+        }
+    }
+
     fn parse(&mut self, instruction: &String) {
         // Opcode is the first character, arguments are everything after the first char
         let opcode = instruction.chars().collect::<Vec<char>>()[0];
-        let arguments = eval::args_or_comments(&instruction[1..]);
 
         if opcode != '#' {
+            let arguments = self.args_or_funcs(&self.args_or_vars(&eval::args_or_comments(&instruction[1..])));
             match opcode {
-                'p' => println!("{}", self.args_or_funcs(&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), '/')),
+                '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, '/')),
                 'l' => self.add_var(&arguments),
                 'f' => self.add_func(&arguments),
                 'i' => self.run_external(arguments),
+                '?' => self.handle_if_statement(arguments),
                 _ => panic!("SyntaxError at opcode {}: Unknown opcode {}", self.pc, opcode),
             }
         }