diff --git a/bfi-rust/src/main.rs b/bfi-rust/src/main.rs index 491f303..de701be 100644 --- a/bfi-rust/src/main.rs +++ b/bfi-rust/src/main.rs @@ -100,6 +100,8 @@ fn interpret(pgm: Vec) -> String { /// most importantly: loop jumps should be immediate /// mod o1 { + use std::io::{stdin, Read}; + const MEM_SIZE: usize = 0xFFFF; type Memory = [u8; MEM_SIZE]; @@ -117,6 +119,12 @@ mod o1 { Loop(Vec), } + fn run(pgm: String) -> String{ + let pgm = minify(pgm); + let pgm = parse(pgm.chars().collect()); + let out = interpret(pgm); + out + } fn minify(code: String) -> String { let allowed: Vec = vec!['>', '<', '+', '-', '.', ',', '[', ']']; @@ -138,7 +146,7 @@ mod o1 { ']' => { let statement = Statement::Loop(loop_stack.pop().unwrap()); loop_stack.last_mut().unwrap().push(statement); - }, + } _ => () } } @@ -146,14 +154,44 @@ mod o1 { return loop_stack.pop().unwrap(); } - fn interpret_o1(pgm: Vec) { + fn interpret(pgm: Vec) -> String { + let mut out = String::new(); + let mut pointer: usize = 0; + let mut mem: [u8; MEM_SIZE] = [0; MEM_SIZE]; + for s in pgm { + execute(&s, &mut mem, &mut pointer, &mut out) + } + + out + } + + fn execute(statement: &Statement, mem: &mut Memory, pointer: &mut usize, mut out: &mut String) { + match statement { + Statement::R => if *pointer == MEM_SIZE - 1 { *pointer = 0 } else { *pointer += 1 }, + Statement::L => if *pointer == 0 { *pointer = MEM_SIZE - 1 } else { *pointer -= 1 }, + Statement::Inc => mem[*pointer] = mem[*pointer].wrapping_add(1), + Statement::Dec => mem[*pointer] = mem[*pointer].wrapping_sub(1), + Statement::Out => out.push(mem[*pointer] as u8 as char), + Statement::In => { + let mut in_buffer = [0, 1]; + stdin().read(&mut in_buffer).unwrap(); + mem[*pointer] = in_buffer[0] as u8; + } + Statement::Loop(vec) => { + while mem[*pointer] != 0 { + for s in vec { + execute(&s, mem, pointer, out); + } + } + } + } } #[cfg(test)] mod test { - use crate::o1::{parse, Statement::{self, Inc, Dec, R, L, In, Out, Loop}}; + use crate::o1::{parse, Statement::{self, Inc, Dec, R, L, In, Out, Loop}, execute}; #[test] fn parse_no_loop() { @@ -181,5 +219,22 @@ mod o1 { assert_eq!(statements, result); } + + + #[test] + fn execute_simple() { + let mut pointer: usize = 0; + let mut mem: [u8; 65535] = [0; 65535]; + let mut out = String::new(); + + execute(&Statement::R, &mut mem, &mut pointer, &mut out); + assert_eq!(pointer, 1); + execute(&Statement::L, &mut mem, &mut pointer, &mut out); + assert_eq!(pointer, 0); + execute(&Statement::Inc, &mut mem, &mut pointer, &mut out); + assert_eq!(mem[pointer], 1); + execute(&Statement::Dec, &mut mem, &mut pointer, &mut out); + assert_eq!(mem[pointer], 0); + } } } \ No newline at end of file