Enum ScriptOperation 

pub enum ScriptOperation<'a, SE: ScriptExpression> {
    None,
    Expression {
        expression: SE,
    },
    DefineRegister {
        query: TypeQuery<'a>,
    },
    DropRegister {
        index: usize,
    },
    PushFromRegister {
        index: usize,
    },
    PopToRegister {
        index: usize,
    },
    MoveRegister {
        from: usize,
        to: usize,
    },
    CallFunction {
        query: FunctionQuery<'a>,
    },
    BranchScope {
        scope_success: ScriptHandle<'a, SE>,
        scope_failure: Option<ScriptHandle<'a, SE>>,
    },
    LoopScope {
        scope: ScriptHandle<'a, SE>,
    },
    PushScope {
        scope: ScriptHandle<'a, SE>,
    },
    PopScope,
    ContinueScopeConditionally,
    Suspend,
}

One instruction of a script.

See the module docs for why the set is this small.

Variants

None

Does nothing.

Expression

Runs a frontend-defined operation. See ScriptExpression.

Fields

expression: SE

DefineRegister

Allocates a register of the queried type.

A register has to be defined before it is used, and is dropped when the scope that defined it ends.

Fields

query: TypeQuery<'a>

DropRegister

Destroys the value in a register, leaving it empty.

Fields

index: usize

PushFromRegister

Moves a register’s value onto the stack, leaving the register empty.

Fields

index: usize

PopToRegister

Moves the top stack value into a register.

Fields

index: usize

MoveRegister

Moves a value from one register to another.

Fields

from: usize

to: usize

CallFunction

Finds a function in the registry and invokes it.

Fields

query: FunctionQuery<'a>

BranchScope

Takes a bool off the stack and runs one of two scopes.

The failure scope is optional, in which case a false does nothing.

Fields

scope_success: ScriptHandle<'a, SE>

scope_failure: Option<ScriptHandle<'a, SE>>

LoopScope

Repeats a scope while a bool taken off the stack is true.

The scope must leave a fresh bool on the stack before it ends, otherwise the next round reads whatever happens to be there.

Fields

scope: ScriptHandle<'a, SE>

PushScope

Runs a nested scope and comes back when it ends.

Fields

scope: ScriptHandle<'a, SE>

PopScope

Ends the current scope early, the way return does.

ContinueScopeConditionally

Takes a bool off the stack and ends the current scope when it is false.

Suspend

Stops stepping and reports back to the caller without finishing.

For frontends building coroutines or futures. Anything to yield has to be left on the stack for the host to take.

Implementations

impl<SE: ScriptExpression> ScriptOperation<'_, SE>

pub fn label(&self) -> &str

Returns the operation’s name, for debugging and tooling.

Trait Implementations

impl<'a, SE: Debug + ScriptExpression> Debug for ScriptOperation<'a, SE>

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

Formats the value using the given formatter.