Implement lexing and some parsing

.gitattributes

@@ -0,0 +1 @@
+*.spcasm linguist-language=Assembly

.gitignore

@@ -8,3 +8,8 @@ Cargo.lock
 
 # These are backup files generated by rustfmt
 **/*.rs.bk
+
+
+# Added by cargo
+
+/target

Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "spcasm"
+version = "0.1.0"
+edition = "2021"
+license = "BSD 2-clause"
+
+[dependencies]

README.md

@@ -7,3 +7,7 @@ spcasm assembles a binary memory dump of the SPC700's main memory. No entry poin
 ## Installation
 
 This is a normal Rust project without special dependencies. Use `cargo` for building, running, testing etc.
+
+## Usage
+
+spcasm follows the mnemonic conventions from [this APU manual](https://web.archive.org/web/20060208001231/http://www.alpha-ii.com/snesmusic/files/spc700_apu_manual.txt). The directive and macro syntax is a subset of the [VASM oldstyle syntax](http://sun.hasenbraten.de/vasm/release/vasm_6.html#Oldstyle-Syntax-Module). If you're missing one of the features here, it would definitely be appreciated here!

examples/test.spcasm

@@ -0,0 +1,18 @@
+MOV A,#$10  
+MOV A,(X)   
+MOV A,(X)+  
+MOV A,$32
+MOV A,$A1+X  
+MOV A,$4502  
+MOV A,$3320+X
+MOV A,$FF00+Y
+MOV A,($40+X)
+MOV A,($20)+Y
+MOV X,#$60  
+MOV X,$9A
+MOV X,$2E+Y  
+MOV X,$2F  
+MOV Y,#$0F
+MOV Y,$48
+MOV Y,$01+X  
+MOV Y,$21