Struct Interpreter 

pub struct Interpreter { /* private fields */ }

A Sema Lisp interpreter instance.

Use InterpreterBuilder for fine-grained control, or call Interpreter::new for a default interpreter with stdlib enabled.

Implementations

impl Interpreter

pub fn new() -> Self

pub fn builder() -> InterpreterBuilder

Create an InterpreterBuilder for fine-grained configuration.

pub fn eval(&self, expr: &Value) -> EvalResult

Evaluate a single parsed Value expression.

Definitions (define) persist across calls.

pub fn eval_str(&self, input: &str) -> EvalResult

Parse and evaluate a string containing one or more Sema expressions.

Definitions (define) persist across calls, so you can define a function in one call and use it in the next.

pub fn register_fn<F>(&self, name: &str, f: F)

where F: Fn(&[Value]) -> Result<Value> + 'static,

Register a native function that can be called from Sema code.

Example

use sema::{Interpreter, Value, SemaError};

let interp = Interpreter::new();
interp.register_fn("square", |args: &[Value]| {
    if let Some(n) = args[0].as_int() {
        Ok(Value::int(n * n))
    } else {
        Err(SemaError::type_error("integer", args[0].type_name()))
    }
});

pub fn global_env(&self) -> &Rc<Env>

Return a reference to the global environment.

pub fn env(&self) -> &Rc<Env>

Trait Implementations

impl Default for Interpreter

fn default() -> Self

Returns the “default value” for a type.