From da99c5b4d1217564d0475e865babef65690833e7 Mon Sep 17 00:00:00 2001
From: aaron <schmocker@puzzle.ch>
Date: Mon, 20 Sep 2021 23:43:05 +0200
Subject: [PATCH] add parser, but machine still stuck in a loop

---
 src/main.rs   |  9 +++++++--
 src/parser.rs | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 10aa188..31cbadf 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,6 +3,7 @@ use std::fs;
 use std::io::{stdin, stdout, BufReader, BufWriter, Read, Write};
 
 use rbfckr::machine::Machine;
+use rbfckr::parser::Parser;
 
 fn main() {
     // try to read from file
@@ -22,13 +23,17 @@ fn main() {
             return;
         }
     };
+
+    // create brainfuck parser and turn the code into instructions
+    let mut parser = Parser::new(code);
+    parser.parse();
     
     // create reader and writer objects
     let mut reader: BufReader<Box<dyn Read>> = BufReader::new(Box::new(stdin()));
     let mut writer: BufWriter<Box<dyn Write>> = BufWriter::new(Box::new(stdout()));
     
-    // create machine
-    let mut machine = Machine::new(code, &mut reader, &mut writer);
+    // create machine and load instructions
+    let mut machine = Machine::new(parser.instructions, &mut reader, &mut writer);
 
     // execute code
     machine.execute();
diff --git a/src/parser.rs b/src/parser.rs
index e69de29..a32310f 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -0,0 +1,51 @@
+use crate::instruction::InstructionType::{ Increment, Decrement, Leftshift, Rightshift, PutChar, GetChar, JumpIfZero, JumpIfNotZero};
+use crate::instruction::{Instruction, InstructionType};
+
+pub struct Parser {
+    code: Box<Vec<char>>,
+    code_length: usize,
+    position: usize,
+    pub instructions: Vec<Instruction>,
+}
+
+impl Parser {
+    pub fn new(code: String) -> Parser {
+        let code_filtered: Vec<char> = code.chars().filter(|c| !c.is_whitespace()).collect();
+        let code_length = &code_filtered.len();
+
+        Parser {
+            code: Box::new(code_filtered),
+            code_length: *code_length,
+            position: 0,
+            instructions: vec![],
+        }
+    }
+
+    pub fn parse(&mut self) {
+        while self.position < self.code_length {
+            let current = self.code[self.position];
+            match current {
+                '+' => self.load_instruction(Increment),
+                '-' => self.load_instruction(Decrement),
+                '<' => self.load_instruction(Leftshift),
+                '>' => self.load_instruction(Rightshift),
+                '.' => self.load_instruction(PutChar),
+                ',' => self.load_instruction(GetChar),
+                '[' => self.load_instruction(JumpIfZero),
+                ']' => self.load_instruction(JumpIfNotZero),
+                _ => (),
+            }
+
+            self.position += 1;
+        }
+    }
+
+    fn load_instruction(&mut self, itype: InstructionType) {
+        let instruction = Instruction {
+            itype,
+            argument: 0,
+        };
+
+        self.instructions.push(instruction);
+    }
+}