Enum FreerComp 

pub enum FreerComp {
    Pure(String),
    Impure {
        effect: String,
        op: String,
        arg: String,
        cont: Box<dyn FnOnce(String) -> FreerComp>,
    },
}

A type-erased representation of the Freer monad for string-typed operations.

FreerComp is either a pure value or an impure node holding an operation description and a continuation.

Variants

Pure(String)

Pure computation: just a string value.

Impure

Impure: an effect name, operation name, argument, and a continuation.

Fields

effect: String

Effect name.

op: String

Operation name.

arg: String

Argument (serialized).

cont: Box<dyn FnOnce(String) -> FreerComp>

Continuation from result string to next computation.

Implementations

impl FreerComp

pub fn pure(v: impl Into<String>) -> Self

Construct a pure Freer computation.

pub fn impure( effect: impl Into<String>, op: impl Into<String>, arg: impl Into<String>, cont: impl FnOnce(String) -> FreerComp + 'static, ) -> Self

Construct an impure Freer computation (one algebraic operation).

pub fn interpret(self, handler: &dyn Fn(&str, &str, &str) -> String) -> String

Interpret the Freer computation using a handler function. handler(effect, op, arg) returns the result string for that operation.

pub fn is_pure(&self) -> bool

Check if this is a pure computation.