ft: Implement memory pointer (Mp) operand

src/operands.rs

@@ -1,7 +1,10 @@
 //! All types which a Mnemonic can have as some kind of operand.
 //! This includes things such as immediates, ModRM byte targets, etc. etc.
 
-use crate::register::Register;
+use crate::{
+    disasm::{DisasmError, Disassembler},
+    register::Register,
+};
 use core::fmt;
 
 pub type Byte = u8; // b
@@ -136,6 +139,33 @@ pub struct Pointer {
     pub offset: Word,
 }
 
+impl Pointer {
+    pub fn new(disasm: &mut Disassembler) -> Result<Self, DisasmError> {
+        let byte0 = disasm
+            .text
+            .get(disasm.offset)
+            .ok_or(DisasmError::IndexOutOfBounds(disasm.offset))?;
+        let byte1 = disasm
+            .text
+            .get(disasm.offset + 1)
+            .ok_or(DisasmError::IndexOutOfBounds(disasm.offset + 1))?;
+        let byte2 = disasm
+            .text
+            .get(disasm.offset + 2)
+            .ok_or(DisasmError::IndexOutOfBounds(disasm.offset + 2))?;
+        let byte3 = disasm
+            .text
+            .get(disasm.offset + 3)
+            .ok_or(DisasmError::IndexOutOfBounds(disasm.offset + 3))?;
+
+        Ok(Pointer {
+            raw: DWord::from_le_bytes([*byte0, *byte1, *byte2, *byte3]),
+            segment: disasm.parse_word(),
+            offset: disasm.parse_word(),
+        })
+    }
+}
+
 impl std::fmt::Display for Pointer {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         write!(f, "[{:#04x}] ({}:{})", self.raw, self.segment, self.offset)