Enum basic::mach::Op

pub enum Op {
    Literal(Val),
    Push(String),
    Pop(String),
    For(Address),
    If(Address),
    Jump(Address),
    Return,
    Clear,
    Cont,
    End,
    Input,
    List,
    Print,
    Stop,
    Neg,
    Exp,
    Mul,
    Div,
    DivInt,
    Mod,
    Add,
    Sub,
    Eq,
    NotEq,
    Lt,
    LtEq,
    Gt,
    GtEq,
    Not,
    And,
    Or,
    Xor,
    Imp,
    Eqv,
}

Virtual machine instruction set

The BASIC virtual machine has no registers. Every operation is performed on the stack.

For example: LET A=3*B compiles to [Literal(3), Push(B), Mul, Pop(A)]

See https://en.wikipedia.org/wiki/Reverse_Polish_notation

Variants

Literal(Val)

Push literal value on to the stack.

Push(String)

Push stack value of named variable. Infallible.

Pop(String)

Pop stack value to named variable. This is the LET statement and may generate errors.

For(Address)

Jumps to Address if the for-loop on the stack is finished.

If(Address)

Pop stack and branch to Address if not zero.

Jump(Address)

Unconditional branch to Address.

Return

Expect Return(Address) on stack or else error: RETURN WITHOUT GOSUB. Branch to Address.

Clear

Cont

End

Input

List

Print

Stop

Neg

Exp

Mul

Div

DivInt

Mod

Add

Sub

Eq

NotEq

Lt

LtEq

Gt

GtEq

Not

And

Or

Xor

Imp

Eqv

Trait Implementations

impl Debug for Op

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Display for Op

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.