feat(assembler): sub instruction and minor reformatting

1 files changed, 12 insertions, 13 deletions

diff --git a/assembler/src/parser/instruction.rs b/assembler/src/parser/instruction.rs
index 8fe21c1..2d6b9ec 100644
--- a/assembler/src/parser/instruction.rs
+++ b/assembler/src/parser/instruction.rs
@@ -61,15 +61,6 @@ impl Instruction {
                     return Err(ArgumentError::NotLocation);
                 }
             },
-            "inc" | "dec" => {
-                self.check_args_len(1)?;
-            },
-            "add" => {
-                self.check_args_len(2)?;
-            },
-            "mov" => {
-                self.check_args_len(2)?;
-            },
             "beq" => {
                 self.check_args_len(2)?;
 
@@ -77,9 +68,14 @@ impl Instruction {
                     return Err(ArgumentError::NotLocation);
                 }
             },
-            "rts" => {
-                self.check_args_len(0)?;
-            },
+
+            "rts"
+                => self.check_args_len(0)?,
+            "inc" | "dec"
+                => self.check_args_len(1)?,
+            "add" | "sub" | "mov"
+                => self.check_args_len(2)?,
+
             _ => return Err(ArgumentError::UnknownInstruction),
         }
         Ok(())
@@ -105,6 +101,9 @@ impl Instruction {
                 Instruction::new_subleq(&Z,            &self.args[1], &Address::Instruction(next + 2)),
                 Instruction::new_subleq(&Z,            &Z,            &Address::Instruction(next + 3)),
             ],
+            "sub" => vec![
+                Instruction::new_subleq(&self.args[0], &self.args[1], &Address::Instruction(next + 1)),
+            ],
             "mov" => vec![
                 Instruction::new_subleq(&self.args[1], &self.args[1], &Address::Instruction(next + 1)),
                 Instruction::new_subleq(&self.args[0], &Z,            &Address::Instruction(next + 2)),
@@ -146,7 +145,7 @@ impl Instruction {
 
     pub(crate) fn collapse_len(&self) -> usize {
         match &*self.name {
-            "subleq" | "jmp" | "inc" | "dec"
+            "subleq" | "jmp" | "inc" | "dec" | "sub"
                 => 1,
             "add"
                 => 3,