Trait Eval

pub trait Eval {
    type State<'a>: Copy + GetSpan;
    type MutState;

    // Required methods
    fn get_config(
        state: Self::State<'_>,
        mut_state: &mut Self::MutState,
    ) -> Arc<Config>;
    fn eval_filepath(
        state: Self::State<'_>,
        mut_state: &mut Self::MutState,
        path: String,
        quoted: bool,
        span: Span,
    ) -> Result<Value, ShellError>;
    fn eval_directory(
        state: Self::State<'_>,
        mut_state: &mut Self::MutState,
        path: String,
        quoted: bool,
        span: Span,
    ) -> Result<Value, ShellError>;
    fn eval_var(
        state: Self::State<'_>,
        mut_state: &mut Self::MutState,
        var_id: VarId,
        span: Span,
    ) -> Result<Value, ShellError>;
    fn eval_call<D: DebugContext>(
        state: Self::State<'_>,
        mut_state: &mut Self::MutState,
        call: &Call,
        span: Span,
    ) -> Result<Value, ShellError>;
    fn eval_external_call(
        state: Self::State<'_>,
        mut_state: &mut Self::MutState,
        head: &Expression,
        args: &[ExternalArgument],
        span: Span,
    ) -> Result<Value, ShellError>;
    fn eval_collect<D: DebugContext>(
        state: Self::State<'_>,
        mut_state: &mut Self::MutState,
        var_id: VarId,
        expr: &Expression,
    ) -> Result<Value, ShellError>;
    fn eval_subexpression<D: DebugContext>(
        state: Self::State<'_>,
        mut_state: &mut Self::MutState,
        block_id: BlockId,
        span: Span,
    ) -> Result<Value, ShellError>;
    fn regex_match(
        state: Self::State<'_>,
        op_span: Span,
        lhs: &Value,
        rhs: &Value,
        invert: bool,
        expr_span: Span,
    ) -> Result<Value, ShellError>;
    fn eval_assignment<D: DebugContext>(
        state: Self::State<'_>,
        mut_state: &mut Self::MutState,
        lhs: &Expression,
        rhs: &Expression,
        assignment: Assignment,
        op_span: Span,
        expr_span: Span,
    ) -> Result<Value, ShellError>;
    fn eval_row_condition_or_closure(
        state: Self::State<'_>,
        mut_state: &mut Self::MutState,
        block_id: BlockId,
        span: Span,
    ) -> Result<Value, ShellError>;
    fn eval_overlay(
        state: Self::State<'_>,
        span: Span,
    ) -> Result<Value, ShellError>;
    fn unreachable(
        state: Self::State<'_>,
        expr: &Expression,
    ) -> Result<Value, ShellError>;

    // Provided method
    fn eval<D: DebugContext>(
        state: Self::State<'_>,
        mut_state: &mut Self::MutState,
        expr: &Expression,
    ) -> Result<Value, ShellError> { ... }
}

To share implementations for regular eval and const eval

Required Associated Types

type State<'a>: Copy + GetSpan

State that doesn’t need to be mutated. EngineState for regular eval and StateWorkingSet for const eval

type MutState

State that needs to be mutated. This is the stack for regular eval, and unused by const eval

Required Methods

fn get_config( state: Self::State<'_>, mut_state: &mut Self::MutState, ) -> Arc<Config>

fn eval_filepath( state: Self::State<'_>, mut_state: &mut Self::MutState, path: String, quoted: bool, span: Span, ) -> Result<Value, ShellError>

fn eval_directory( state: Self::State<'_>, mut_state: &mut Self::MutState, path: String, quoted: bool, span: Span, ) -> Result<Value, ShellError>

fn eval_var( state: Self::State<'_>, mut_state: &mut Self::MutState, var_id: VarId, span: Span, ) -> Result<Value, ShellError>

fn eval_call<D: DebugContext>( state: Self::State<'_>, mut_state: &mut Self::MutState, call: &Call, span: Span, ) -> Result<Value, ShellError>

fn eval_external_call( state: Self::State<'_>, mut_state: &mut Self::MutState, head: &Expression, args: &[ExternalArgument], span: Span, ) -> Result<Value, ShellError>

fn eval_collect<D: DebugContext>( state: Self::State<'_>, mut_state: &mut Self::MutState, var_id: VarId, expr: &Expression, ) -> Result<Value, ShellError>

fn eval_subexpression<D: DebugContext>( state: Self::State<'_>, mut_state: &mut Self::MutState, block_id: BlockId, span: Span, ) -> Result<Value, ShellError>

fn regex_match( state: Self::State<'_>, op_span: Span, lhs: &Value, rhs: &Value, invert: bool, expr_span: Span, ) -> Result<Value, ShellError>

fn eval_assignment<D: DebugContext>( state: Self::State<'_>, mut_state: &mut Self::MutState, lhs: &Expression, rhs: &Expression, assignment: Assignment, op_span: Span, expr_span: Span, ) -> Result<Value, ShellError>

fn eval_row_condition_or_closure( state: Self::State<'_>, mut_state: &mut Self::MutState, block_id: BlockId, span: Span, ) -> Result<Value, ShellError>

fn eval_overlay(state: Self::State<'_>, span: Span) -> Result<Value, ShellError>

fn unreachable( state: Self::State<'_>, expr: &Expression, ) -> Result<Value, ShellError>

For expressions that should never actually be evaluated

Provided Methods

fn eval<D: DebugContext>( state: Self::State<'_>, mut_state: &mut Self::MutState, expr: &Expression, ) -> Result<Value, ShellError>

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors