Add unary+, unary-

src/vstc/assemble.rs

@@ -242,6 +242,8 @@ impl<'a> Assembler for AssemblerData<'a> {
       ("subcall", Instruction::SubCall),
       ("jmp", Instruction::Jmp),
       ("jmpif", Instruction::JmpIf),
+      ("unary+", Instruction::UnaryPlus),
+      ("unary-", Instruction::UnaryMinus),
     ]);
 
     for (word, instruction) in instruction_word_map {
@@ -811,6 +813,8 @@ enum Instruction {
   SubCall = 0x26,
   Jmp = 0x27,
   JmpIf = 0x28,
+  UnaryPlus = 0x29,
+  UnaryMinus = 0x2a,
 }
 
 enum InstructionArg {
@@ -865,6 +869,8 @@ fn get_instruction_layout(instruction: Instruction) -> Vec<InstructionArg> {
     SubCall => Vec::from([Value, Value, Value, Register]),
     Jmp => Vec::from([Label]),
     JmpIf => Vec::from([Value, Label]),
+    UnaryPlus => Vec::from([Value, Register]),
+    UnaryMinus => Vec::from([Value, Register]),
   };
 }
 

src/vstc/virtual_machine/instruction.rs

@@ -44,6 +44,8 @@ pub enum Instruction {
   SubCall = 0x26,
   Jmp = 0x27,
   JmpIf = 0x28,
+  UnaryPlus = 0x29,
+  UnaryMinus = 0x2a,
 }
 
 impl Instruction {
@@ -92,6 +94,8 @@ impl Instruction {
       0x26 => SubCall,
       0x27 => Jmp,
       0x28 => JmpIf,
+      0x29 => UnaryPlus,
+      0x2a => UnaryMinus,
 
       _ => std::panic!("Unrecognized instruction: {}", byte),
     };

src/vstc/virtual_machine/operations.rs

@@ -15,10 +15,18 @@ pub fn op_plus(left: Val, right: Val) -> Val {
   return Val::Number(left_prim.to_number() + right_prim.to_number());
 }
 
+pub fn op_unary_plus(input: Val) -> Val {
+  return Val::Number(input.to_number());
+}
+
 pub fn op_minus(left: Val, right: Val) -> Val {
   return Val::Number(left.to_number() - right.to_number());
 }
 
+pub fn op_unary_minus(input: Val) -> Val {
+  return Val::Number(-input.to_number());
+}
+
 pub fn op_mul(left: Val, right: Val) -> Val {
   return Val::Number(left.to_number() * right.to_number());
 }

src/vstc/virtual_machine/virtual_machine.rs

@@ -259,6 +259,9 @@ impl VirtualMachine {
           frame.decoder.pos = dst;
         }
       }
+
+      UnaryPlus => frame.apply_unary_op(operations::op_unary_plus),
+      UnaryMinus => frame.apply_unary_op(operations::op_unary_minus),
     };
   }