rhai/src/api/run.rs
2021-11-29 09:43:35 +08:00

81 lines
2.7 KiB
Rust

//! Module that defines the public evaluation API of [`Engine`].
use crate::engine::{EvalState, Imports};
use crate::parser::ParseState;
use crate::{Engine, EvalAltResult, Module, Scope, AST};
#[cfg(feature = "no_std")]
use std::prelude::v1::*;
impl Engine {
/// Evaluate a script, returning any error (if any).
#[inline(always)]
pub fn run(&self, script: &str) -> Result<(), Box<EvalAltResult>> {
self.run_with_scope(&mut Scope::new(), script)
}
/// Evaluate a script with own scope, returning any error (if any).
///
/// ## Constants Propagation
///
/// If not [`OptimizationLevel::None`][crate::OptimizationLevel::None], constants defined within
/// the scope are propagated throughout the script _including_ functions. This allows functions
/// to be optimized based on dynamic global constants.
#[inline]
pub fn run_with_scope(
&self,
scope: &mut Scope,
script: &str,
) -> Result<(), Box<EvalAltResult>> {
let scripts = [script];
let (stream, tokenizer_control) =
self.lex_raw(&scripts, self.token_mapper.as_ref().map(Box::as_ref));
let mut state = ParseState::new(self, tokenizer_control);
let ast = self.parse(
&mut stream.peekable(),
&mut state,
scope,
#[cfg(not(feature = "no_optimize"))]
self.optimization_level,
)?;
self.run_ast_with_scope(scope, &ast)
}
/// Evaluate an [`AST`], returning any error (if any).
#[inline(always)]
pub fn run_ast(&self, ast: &AST) -> Result<(), Box<EvalAltResult>> {
self.run_ast_with_scope(&mut Scope::new(), ast)
}
/// Evaluate an [`AST`] with own scope, returning any error (if any).
#[inline]
pub fn run_ast_with_scope(
&self,
scope: &mut Scope,
ast: &AST,
) -> Result<(), Box<EvalAltResult>> {
let mods = &mut Imports::new();
let mut state = EvalState::new();
if ast.source_raw().is_some() {
mods.source = ast.source_raw().cloned();
}
#[cfg(not(feature = "no_module"))]
{
mods.embedded_module_resolver = ast.resolver().cloned();
}
let statements = ast.statements();
if !statements.is_empty() {
let lib = [
#[cfg(not(feature = "no_function"))]
ast.as_ref(),
];
let lib = if lib.first().map(|m: &&Module| m.is_empty()).unwrap_or(true) {
&lib[0..0]
} else {
&lib
};
self.eval_global_statements(scope, mods, &mut state, statements, lib, 0)?;
}
Ok(())
}
}