Bob Reversible ISA - Syntax

Bob has a very simple syntax. Instructions are separated with newlines. Semicolons have been added as separators. An instruction is followed by zero or more arguments separated with spaces. These can be of the following types

Register: prefixed with $ as so: $reg1
Immediate values: these are integers and are just written as 1234
Memory references: these are written within square brackets. Both registers and immediate values can be written within a memory reference. Furthermore each argument within the memory reference can be summed, subtracted or multiplied with other arguments. Here arithmetic precedence and associativity is present. Furthermore memory references can be nested, as so [$reg1 + 100 * $reg2 - [$reg1 - $reg2]]
List of arguments: these are written within normal parentheses and are separated with commas as so ($reg1,$reg2)

The syntax of Bob is here presented in BNF

Lines       \rightarrow \epsilon
             | Stmt eol Lines
Stmt        \rightarrow \epsilon
             | id StmtType
StmtType    \rightarrow :
             | Args
Args        \rightarrow \epsilon
             | reg Args
             | imm Args
             | id Args
             | [ ArgM ] Args
             | ( ArgList ) Args
ArgM        \rightarrow ArgM + ArgM
             | ArgM - ArgM
             | ArgM * ArgM
             | ArgMLit
ArgMLit     \rightarrow [ ArgM ]
             | reg
             | imm
ArgList     \rightarrow \epsilon
             | reg ArgListC
ArgListC    \rightarrow \epsilon
             | , reg ArgListC

It has been made to fit a SLR parser.