Implemented HLT instruction

- Instructions are now detected automatically based on context
- Since MIPs can't decide if it wants to be open or not, Corten will be aiming to be more of a RISC-V VM in the long term.

src/assembler/instruction_parser.rs

@@ -1,9 +1,8 @@
-use nom::*;
-use crate::assembler::Token;
-use crate::assembler::opcode_parser::opcode_load;
+use crate::assembler::opcode_parser::opcode;
 use crate::assembler::operand_parser::integer_operand;
 use crate::assembler::register_parser::register;
-
+use crate::assembler::Token;
+use nom::*;
 use nom::types::CompleteStr;
 
 #[derive(Debug, PartialEq)]
@@ -30,7 +29,6 @@ impl AssemblerInstruction {
             }
         };
 
-
         for operand in &[&self.operand1, &self.operand2, &self.operand3] {
             if let Some(token) = operand {
                 AssemblerInstruction::extract_operand(token, &mut results)
@@ -44,7 +42,7 @@ impl AssemblerInstruction {
         match t {
             Token::Register { reg_num } => {
                 results.push(*reg_num);
-            },
+            }
             Token::Number { value } => {
                 let conv = *value as u16;
                 let byte1 = conv;
@@ -52,19 +50,45 @@ impl AssemblerInstruction {
 
                 results.push(byte2 as u8);
                 results.push(byte1 as u8);
-            },
+            }
             _ => {
                 println!("Opcode found in operand field");
                 std::process::exit(1);
             }
         };
     }
-
 }
 
-named!(pub instruction_one<CompleteStr, AssemblerInstruction>,
+named!(instruction_two<CompleteStr, AssemblerInstruction>,
     do_parse!(
-        o: opcode_load >>
+        o: opcode >>
+        opt!(multispace) >>
+        (
+            AssemblerInstruction{
+                opcode: o,
+                operand1: None,
+                operand2: None,
+                operand3: None
+            }
+        )
+    )
+);
+
+named!(pub instruction<CompleteStr, AssemblerInstruction>,
+    do_parse!(
+        ins: alt!(
+            instruction_one |
+            instruction_two
+        ) >>
+        (
+        ins
+        )
+    )
+);
+
+named!(instruction_one<CompleteStr, AssemblerInstruction>,
+    do_parse!(
+        o: opcode >>
         r: register >>
         i: integer_operand >>
         (
@@ -99,4 +123,21 @@ mod instruction_parser_test {
             ))
         );
     }
+
+    #[test]
+    fn test_parse_instruction_form_two() {
+        let result = instruction_two(CompleteStr("hlt\n"));
+        assert_eq!(
+            result,
+            Ok((
+                CompleteStr(""),
+                AssemblerInstruction {
+                    opcode: Token::Opcode { code: Opcode::HLT },
+                    operand1: None,
+                    operand2: None,
+                    operand3: None
+                }
+            ))
+        );
+    }
 }