bring overhaul to master branch

.gitignore

@@ -1,3 +1,2 @@
 /target/
-/temp/
 /Cargo.lock

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "customasm"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Henrique Lorenzi <[email protected]>"]
 
 [lib]
@@ -12,4 +12,5 @@ name = "customasm"
 path = "src/main.rs"
 
 [dependencies]
-getopts = "0.2.14"
+getopts = "0.2.14"
+num = "0.1.40"

README.md

@@ -1,44 +1,47 @@
 # customasm
-This is an assembler that takes custom instruction set definitions,
-and assembles files based on that.  
+This is an assembler that takes custom instruction set definitions
+and uses them to assemble source files.  
 This can be useful if you'd like to test out a new virtual machine's bytecode,
 or even if you're eager to write programs for that new processor architecture 
-you just implemented in FPGA!  
+you just implemented in FPGA!
+
 Check out the Releases section for pre-built binaries.  
 
 Check out the documentation for usage instructions:
-- [Definition File Format](/doc/def.md)
+- [Instruction Set File Format](/doc/instrset.md)
 - [Source File Format](/doc/src.md)
 
 ```
-Usage: customasm [options] <def-file> <asm-file> [<out-file>]
+Usage: customasm [options] <instrset-file> <asm-file>
 
 Options:
     -h, --help          Display this information.
     -v, --version       Display version information.
     -q, --quiet         Suppress progress reports.
     -f, --format FORMAT The format of the output file. Possible formats:
                         binary, binstr, hexstr, bindump, hexdump
+    -o, --out-data FILE The name of the output file. (Default: a.out)
+        --stdout        Write output to stdout instead of a file.
 ```
 
-The idea is that, given this definition file:
+The idea is that, given the following Instruction Set file:
 
 ```
 #align 8
 
-load r1, {value: _ <= 0xff} -> 8'0x11 value[7:0]
-load r2, {value: _ <= 0xff} -> 8'0x12 value[7:0]
-load r3, {value: _ <= 0xff} -> 8'0x13 value[7:0]
-add  r1, r2                 -> 8'0x21
-sub  r3, {value: _ <= 0xff} -> 8'0x33 value[7:0]
-jnz  {address: _ <= 0xffff} -> 8'0x40 address[15:0]
-ret                         -> 8'0x50
+load r1, {value} -> 8'0x11 @ value[7:0]
+load r2, {value} -> 8'0x12 @ value[7:0]
+load r3, {value} -> 8'0x13 @ value[7:0]
+add  r1, r2      -> 8'0x21
+sub  r3, {value} -> 8'0x33 @ value[7:0]
+jnz  {address}   -> 8'0x40 @ address[15:0]
+ret              -> 8'0x50
 ```
 
-...the assembler would take this file:
+...the assembler would take the following Source file:
 
 ```
-#address 0x8000
+#addr 0x8000
 
 multiply3x4:
 	load r1, 0