927 lines
34 KiB
Rust
927 lines
34 KiB
Rust
use std::any::TypeId;
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use std::cmp::{PartialEq, PartialOrd};
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use std::collections::HashMap;
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use std::error::Error;
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use std::sync::Arc;
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use crate::any::{Any, AnyExt, Dynamic, Variant};
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use crate::call::FunArgs;
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use crate::fn_register::RegisterFn;
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use crate::parser::{Expr, FnDef, ParseError, Position, Stmt};
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use crate::scope::Scope;
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pub type Array = Vec<Dynamic>;
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pub type FnCallArgs<'a> = Vec<&'a mut Variant>;
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#[derive(Debug)]
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pub enum EvalAltResult {
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ErrorParsing(ParseError),
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ErrorFunctionNotFound(String, Position),
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ErrorFunctionArgsMismatch(String, usize, Position),
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ErrorBooleanArgMismatch(String, Position),
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ErrorArrayBounds(usize, i64, Position),
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ErrorStringBounds(usize, i64, Position),
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ErrorIndexing(Position),
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ErrorIndexExpr(Position),
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ErrorIfGuard(Position),
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ErrorFor(Position),
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ErrorVariableNotFound(String, Position),
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ErrorAssignmentToUnknownLHS(Position),
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ErrorMismatchOutputType(String, Position),
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ErrorCantOpenScriptFile(String, std::io::Error),
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ErrorDotExpr(Position),
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ErrorArithmetic(String, Position),
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LoopBreak,
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Return(Dynamic, Position),
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}
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impl Error for EvalAltResult {
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fn description(&self) -> &str {
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match self {
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Self::ErrorParsing(p) => p.description(),
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Self::ErrorFunctionNotFound(_, _) => "Function not found",
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Self::ErrorFunctionArgsMismatch(_, _, _) => {
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"Function call with wrong number of arguments"
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}
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Self::ErrorBooleanArgMismatch(_, _) => "Boolean operator expects boolean operands",
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Self::ErrorIndexExpr(_) => "Indexing into an array or string expects an integer index",
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Self::ErrorIndexing(_) => "Indexing can only be performed on an array or a string",
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Self::ErrorArrayBounds(_, index, _) if *index < 0 => {
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"Array access expects non-negative index"
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}
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Self::ErrorArrayBounds(max, _, _) if *max == 0 => "Access of empty array",
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Self::ErrorArrayBounds(_, _, _) => "Array index out of bounds",
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Self::ErrorStringBounds(_, index, _) if *index < 0 => {
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"Indexing a string expects a non-negative index"
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}
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Self::ErrorStringBounds(max, _, _) if *max == 0 => "Indexing of empty string",
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Self::ErrorStringBounds(_, _, _) => "String index out of bounds",
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Self::ErrorIfGuard(_) => "If guard expects boolean expression",
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Self::ErrorFor(_) => "For loop expects array or range",
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Self::ErrorVariableNotFound(_, _) => "Variable not found",
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Self::ErrorAssignmentToUnknownLHS(_) => {
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"Assignment to an unsupported left-hand side expression"
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}
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Self::ErrorMismatchOutputType(_, _) => "Output type is incorrect",
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Self::ErrorCantOpenScriptFile(_, _) => "Cannot open script file",
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Self::ErrorDotExpr(_) => "Malformed dot expression",
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Self::ErrorArithmetic(_, _) => "Arithmetic error",
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Self::LoopBreak => "[Not Error] Breaks out of loop",
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Self::Return(_, _) => "[Not Error] Function returns value",
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}
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}
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fn cause(&self) -> Option<&dyn Error> {
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None
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}
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}
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impl std::fmt::Display for EvalAltResult {
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fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
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let desc = self.description();
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match self {
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Self::ErrorFunctionNotFound(s, pos) => write!(f, "{}: '{}' ({})", desc, s, pos),
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Self::ErrorVariableNotFound(s, pos) => write!(f, "{}: '{}' ({})", desc, s, pos),
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Self::ErrorIndexing(pos) => write!(f, "{} ({})", desc, pos),
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Self::ErrorIndexExpr(pos) => write!(f, "{} ({})", desc, pos),
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Self::ErrorIfGuard(pos) => write!(f, "{} ({})", desc, pos),
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Self::ErrorFor(pos) => write!(f, "{} ({})", desc, pos),
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Self::ErrorAssignmentToUnknownLHS(pos) => write!(f, "{} ({})", desc, pos),
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Self::ErrorMismatchOutputType(s, pos) => write!(f, "{}: {} ({})", desc, s, pos),
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Self::ErrorDotExpr(pos) => write!(f, "{} ({})", desc, pos),
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Self::ErrorArithmetic(s, pos) => write!(f, "{}: {} ({})", desc, s, pos),
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Self::LoopBreak => write!(f, "{}", desc),
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Self::Return(_, pos) => write!(f, "{} ({})", desc, pos),
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Self::ErrorCantOpenScriptFile(filename, err) => {
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write!(f, "{} '{}': {}", desc, filename, err)
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}
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Self::ErrorParsing(p) => write!(f, "Syntax error: {}", p),
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Self::ErrorFunctionArgsMismatch(fun, n, pos) => {
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write!(f, "Function '{}' expects {} argument(s) ({})", fun, n, pos)
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}
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Self::ErrorBooleanArgMismatch(op, pos) => {
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write!(f, "{} operator expects boolean operands ({})", op, pos)
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}
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Self::ErrorArrayBounds(_, index, pos) if *index < 0 => {
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write!(f, "{}: {} < 0 ({})", desc, index, pos)
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}
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Self::ErrorArrayBounds(max, _, pos) if *max == 0 => write!(f, "{} ({})", desc, pos),
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Self::ErrorArrayBounds(max, index, pos) => {
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write!(f, "{} (max {}): {} ({})", desc, max - 1, index, pos)
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}
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Self::ErrorStringBounds(_, index, pos) if *index < 0 => {
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write!(f, "{}: {} < 0 ({})", desc, index, pos)
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}
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Self::ErrorStringBounds(max, _, pos) if *max == 0 => write!(f, "{} ({})", desc, pos),
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Self::ErrorStringBounds(max, index, pos) => {
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write!(f, "{} (max {}): {} ({})", desc, max - 1, index, pos)
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}
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}
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}
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}
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#[derive(Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
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pub struct FnSpec {
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pub ident: String,
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pub args: Option<Vec<TypeId>>,
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}
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type IteratorFn = dyn Fn(&Dynamic) -> Box<dyn Iterator<Item = Dynamic>>;
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/// Rhai's engine type. This is what you use to run Rhai scripts
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///
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/// ```rust
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/// extern crate rhai;
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/// use rhai::Engine;
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///
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/// fn main() {
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/// let mut engine = Engine::new();
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///
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/// if let Ok(result) = engine.eval::<i64>("40 + 2") {
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/// println!("Answer: {}", result); // prints 42
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/// }
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/// }
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/// ```
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pub struct Engine {
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/// A hashmap containing all compiled functions known to the engine
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fns: HashMap<FnSpec, Arc<FnIntExt>>,
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/// A hashmap containing all script-defined functions
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pub(crate) script_fns: HashMap<FnSpec, Arc<FnIntExt>>,
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/// A hashmap containing all iterators known to the engine
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type_iterators: HashMap<TypeId, Arc<IteratorFn>>,
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type_names: HashMap<String, String>,
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pub(crate) on_print: Box<dyn Fn(&str)>,
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pub(crate) on_debug: Box<dyn Fn(&str)>,
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}
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pub enum FnIntExt {
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Ext(Box<FnAny>),
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Int(FnDef),
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}
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pub type FnAny = dyn Fn(FnCallArgs, Position) -> Result<Dynamic, EvalAltResult>;
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impl Engine {
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pub fn call_fn<'a, I, A, T>(&self, ident: I, args: A) -> Result<T, EvalAltResult>
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where
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I: Into<String>,
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A: FunArgs<'a>,
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T: Any + Clone,
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{
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let pos = Position::new();
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self.call_fn_raw(ident.into(), args.into_vec(), None, pos)
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.and_then(|b| {
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b.downcast().map(|b| *b).map_err(|a| {
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EvalAltResult::ErrorMismatchOutputType(
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self.map_type_name((*a).type_name()).into(),
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pos,
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)
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})
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})
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}
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/// Universal method for calling functions, that are either
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/// registered with the `Engine` or written in Rhai
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fn call_fn_raw(
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&self,
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ident: String,
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args: FnCallArgs,
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def_value: Option<&Dynamic>,
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pos: Position,
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) -> Result<Dynamic, EvalAltResult> {
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debug_println!(
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"Calling {}({})",
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ident,
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args.iter()
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.map(|x| (*x).type_name())
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.map(|name| self.map_type_name(name))
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.collect::<Vec<_>>()
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.join(", ")
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);
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let mut spec = FnSpec { ident, args: None };
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// First search in script-defined functions (can override built-in),
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// then in built-in's
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let fn_def = self.script_fns.get(&spec).or_else(|| {
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spec.args = Some(args.iter().map(|a| Any::type_id(&**a)).collect());
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self.fns.get(&spec)
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});
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if let Some(f) = fn_def {
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match **f {
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FnIntExt::Ext(ref f) => {
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let r = f(args, pos);
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if r.is_err() {
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return r;
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}
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let callback = match spec.ident.as_str() {
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"print" => &self.on_print,
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"debug" => &self.on_debug,
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_ => return r,
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};
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Ok(Box::new(callback(
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r.unwrap()
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.downcast::<String>()
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.map(|x| *x)
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.unwrap_or("error: not a string".into())
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.as_str(),
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)))
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}
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FnIntExt::Int(ref f) => {
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let mut scope = Scope::new();
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scope.extend(
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f.params
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.iter()
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.cloned()
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.zip(args.iter().map(|x| (*x).into_dynamic())),
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);
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match self.eval_stmt(&mut scope, &*f.body) {
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Err(EvalAltResult::Return(x, _)) => Ok(x),
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other => other,
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}
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}
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}
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} else if let Some(val) = def_value {
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// Return default value
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Ok(val.clone())
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} else {
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let types_list = args
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.iter()
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.map(|x| (*x).type_name())
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.map(|name| self.map_type_name(name))
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.collect::<Vec<_>>();
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Err(EvalAltResult::ErrorFunctionNotFound(
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format!("{} ({})", spec.ident, types_list.join(", ")),
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pos,
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))
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}
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}
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pub(crate) fn register_fn_raw(
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&mut self,
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ident: String,
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args: Option<Vec<TypeId>>,
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f: Box<FnAny>,
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) {
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debug_println!("Register; {:?} with args {:?}", ident, args);
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let spec = FnSpec { ident, args };
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self.fns.insert(spec, Arc::new(FnIntExt::Ext(f)));
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}
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/// Register a type for use with Engine. Keep in mind that
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/// your type must implement Clone.
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pub fn register_type<T: Any>(&mut self) {
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// currently a no-op, exists for future extensibility
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}
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/// Register an iterator adapter for a type.
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pub fn register_iterator<T: Any, F>(&mut self, f: F)
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where
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F: Fn(&Dynamic) -> Box<dyn Iterator<Item = Dynamic>> + 'static,
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{
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self.type_iterators.insert(TypeId::of::<T>(), Arc::new(f));
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}
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/// Register a get function for a member of a registered type
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pub fn register_get<T: Any + Clone, U: Any + Clone>(
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&mut self,
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name: &str,
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get_fn: impl Fn(&mut T) -> U + 'static,
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) {
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let get_name = "get$".to_string() + name;
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self.register_fn(&get_name, get_fn);
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}
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/// Register a set function for a member of a registered type
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pub fn register_set<T: Any + Clone, U: Any + Clone>(
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&mut self,
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name: &str,
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set_fn: impl Fn(&mut T, U) -> () + 'static,
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) {
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let set_name = "set$".to_string() + name;
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self.register_fn(&set_name, set_fn);
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}
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/// Shorthand for registering both getters and setters
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pub fn register_get_set<T: Any + Clone, U: Any + Clone>(
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&mut self,
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name: &str,
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get_fn: impl Fn(&mut T) -> U + 'static,
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set_fn: impl Fn(&mut T, U) -> () + 'static,
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) {
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self.register_get(name, get_fn);
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self.register_set(name, set_fn);
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}
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fn get_dot_val_helper(
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&self,
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scope: &mut Scope,
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this_ptr: &mut Variant,
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dot_rhs: &Expr,
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) -> Result<Dynamic, EvalAltResult> {
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use std::iter::once;
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match dot_rhs {
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Expr::FunctionCall(fn_name, args, def_value, pos) => {
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let mut args: Array = args
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.iter()
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.map(|arg| self.eval_expr(scope, arg))
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.collect::<Result<Vec<_>, _>>()?;
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let args = once(this_ptr)
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.chain(args.iter_mut().map(|b| b.as_mut()))
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.collect();
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self.call_fn_raw(fn_name.into(), args, def_value.as_ref(), *pos)
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}
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Expr::Identifier(id, pos) => {
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let get_fn_name = "get$".to_string() + id;
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self.call_fn_raw(get_fn_name, vec![this_ptr], None, *pos)
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}
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Expr::Index(id, idx_raw, pos) => {
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let idx = self
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.eval_expr(scope, idx_raw)?
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.downcast_ref::<i64>()
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.map(|i| *i)
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.ok_or(EvalAltResult::ErrorIndexExpr(idx_raw.position()))?;
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let get_fn_name = "get$".to_string() + id;
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let mut val = self.call_fn_raw(get_fn_name, vec![this_ptr], None, *pos)?;
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if let Some(arr) = val.downcast_mut() as Option<&mut Array> {
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if idx >= 0 {
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arr.get(idx as usize)
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.cloned()
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.ok_or_else(|| EvalAltResult::ErrorArrayBounds(arr.len(), idx, *pos))
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} else {
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Err(EvalAltResult::ErrorArrayBounds(arr.len(), idx, *pos))
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}
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} else if let Some(s) = val.downcast_mut() as Option<&mut String> {
|
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if idx >= 0 {
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s.chars()
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.nth(idx as usize)
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.map(|ch| Box::new(ch) as Dynamic)
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.ok_or_else(|| {
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EvalAltResult::ErrorStringBounds(s.chars().count(), idx, *pos)
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})
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} else {
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Err(EvalAltResult::ErrorStringBounds(
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s.chars().count(),
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idx,
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*pos,
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))
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}
|
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} else {
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Err(EvalAltResult::ErrorIndexing(*pos))
|
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}
|
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}
|
|
|
|
Expr::Dot(inner_lhs, inner_rhs) => match **inner_lhs {
|
|
Expr::Identifier(ref id, pos) => {
|
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let get_fn_name = "get$".to_string() + id;
|
|
let value = self
|
|
.call_fn_raw(get_fn_name, vec![this_ptr], None, pos)
|
|
.and_then(|mut v| self.get_dot_val_helper(scope, v.as_mut(), inner_rhs))?;
|
|
|
|
// TODO - Should propagate changes back in this scenario:
|
|
//
|
|
// fn update(p) { p = something_else; }
|
|
// obj.prop.update();
|
|
//
|
|
// Right now, a copy of the object's property value is mutated, but not propagated
|
|
// back to the property via $set.
|
|
|
|
Ok(value)
|
|
}
|
|
Expr::Index(_, _, pos) => {
|
|
// TODO - Handle Expr::Index for these scenarios:
|
|
//
|
|
// let x = obj.prop[2].x;
|
|
// obj.prop[3] = 42;
|
|
//
|
|
Err(EvalAltResult::ErrorDotExpr(pos))
|
|
}
|
|
_ => Err(EvalAltResult::ErrorDotExpr(inner_lhs.position())),
|
|
},
|
|
|
|
_ => Err(EvalAltResult::ErrorDotExpr(dot_rhs.position())),
|
|
}
|
|
}
|
|
|
|
fn search_scope<T>(
|
|
scope: &Scope,
|
|
id: &str,
|
|
map: impl FnOnce(&Variant) -> Result<T, EvalAltResult>,
|
|
begin: Position,
|
|
) -> Result<(usize, T), EvalAltResult> {
|
|
scope
|
|
.get(id)
|
|
.ok_or_else(|| EvalAltResult::ErrorVariableNotFound(id.into(), begin))
|
|
.and_then(move |(idx, _, val)| map(val.as_ref()).map(|v| (idx, v)))
|
|
}
|
|
|
|
fn indexed_value(
|
|
&self,
|
|
scope: &mut Scope,
|
|
id: &str,
|
|
idx: &Expr,
|
|
begin: Position,
|
|
) -> Result<(bool, usize, usize, Dynamic), EvalAltResult> {
|
|
let idx = *self
|
|
.eval_expr(scope, idx)?
|
|
.downcast::<i64>()
|
|
.map_err(|_| EvalAltResult::ErrorIndexExpr(idx.position()))?;
|
|
|
|
let mut is_array = false;
|
|
|
|
Self::search_scope(
|
|
scope,
|
|
id,
|
|
|val| {
|
|
if let Some(arr) = val.downcast_ref() as Option<&Array> {
|
|
is_array = true;
|
|
|
|
if idx >= 0 {
|
|
arr.get(idx as usize)
|
|
.cloned()
|
|
.ok_or_else(|| EvalAltResult::ErrorArrayBounds(arr.len(), idx, begin))
|
|
} else {
|
|
Err(EvalAltResult::ErrorArrayBounds(arr.len(), idx, begin))
|
|
}
|
|
} else if let Some(s) = val.downcast_ref() as Option<&String> {
|
|
is_array = false;
|
|
|
|
if idx >= 0 {
|
|
s.chars()
|
|
.nth(idx as usize)
|
|
.map(|ch| Box::new(ch) as Dynamic)
|
|
.ok_or_else(|| {
|
|
EvalAltResult::ErrorStringBounds(s.chars().count(), idx, begin)
|
|
})
|
|
} else {
|
|
Err(EvalAltResult::ErrorStringBounds(
|
|
s.chars().count(),
|
|
idx,
|
|
begin,
|
|
))
|
|
}
|
|
} else {
|
|
Err(EvalAltResult::ErrorIndexing(begin))
|
|
}
|
|
},
|
|
begin,
|
|
)
|
|
.map(|(idx_sc, val)| (is_array, idx_sc, idx as usize, val))
|
|
}
|
|
|
|
fn str_replace_char(s: &mut String, idx: usize, new_ch: char) {
|
|
// The new character
|
|
let ch = s.chars().nth(idx).unwrap();
|
|
|
|
// See if changed - if so, update the String
|
|
if ch == new_ch {
|
|
return;
|
|
}
|
|
|
|
// Collect all the characters after the index
|
|
let mut chars: Vec<char> = s.chars().collect();
|
|
chars[idx] = new_ch;
|
|
s.clear();
|
|
chars.iter().for_each(|&ch| s.push(ch));
|
|
}
|
|
|
|
fn get_dot_val(
|
|
&self,
|
|
scope: &mut Scope,
|
|
dot_lhs: &Expr,
|
|
dot_rhs: &Expr,
|
|
) -> Result<Dynamic, EvalAltResult> {
|
|
match dot_lhs {
|
|
Expr::Identifier(id, pos) => {
|
|
let (sc_idx, mut target) =
|
|
Self::search_scope(scope, id, |x| Ok(x.into_dynamic()), *pos)?;
|
|
let value = self.get_dot_val_helper(scope, target.as_mut(), dot_rhs);
|
|
|
|
// In case the expression mutated `target`, we need to reassign it because
|
|
// of the above `clone`.
|
|
*scope.get_mut(id, sc_idx) = target;
|
|
|
|
value
|
|
}
|
|
|
|
Expr::Index(id, idx_raw, pos) => {
|
|
let (is_array, sc_idx, idx, mut target) =
|
|
self.indexed_value(scope, id, idx_raw, *pos)?;
|
|
let value = self.get_dot_val_helper(scope, target.as_mut(), dot_rhs);
|
|
|
|
// In case the expression mutated `target`, we need to reassign it because
|
|
// of the above `clone`.
|
|
|
|
if is_array {
|
|
scope.get_mut(id, sc_idx).downcast_mut::<Array>().unwrap()[idx] = target;
|
|
} else {
|
|
Self::str_replace_char(
|
|
scope.get_mut(id, sc_idx).downcast_mut::<String>().unwrap(), // Root is a string
|
|
idx,
|
|
*target.downcast::<char>().unwrap(), // Target should be a char
|
|
);
|
|
}
|
|
|
|
value
|
|
}
|
|
|
|
_ => Err(EvalAltResult::ErrorDotExpr(dot_lhs.position())),
|
|
}
|
|
}
|
|
|
|
fn set_dot_val_helper(
|
|
&self,
|
|
this_ptr: &mut Variant,
|
|
dot_rhs: &Expr,
|
|
mut source_val: Dynamic,
|
|
) -> Result<Dynamic, EvalAltResult> {
|
|
match dot_rhs {
|
|
Expr::Identifier(id, pos) => {
|
|
let set_fn_name = "set$".to_string() + id;
|
|
|
|
self.call_fn_raw(set_fn_name, vec![this_ptr, source_val.as_mut()], None, *pos)
|
|
}
|
|
|
|
Expr::Dot(inner_lhs, inner_rhs) => match **inner_lhs {
|
|
Expr::Identifier(ref id, pos) => {
|
|
let get_fn_name = "get$".to_string() + id;
|
|
|
|
self.call_fn_raw(get_fn_name, vec![this_ptr], None, pos)
|
|
.and_then(|mut v| {
|
|
self.set_dot_val_helper(v.as_mut(), inner_rhs, source_val)
|
|
.map(|_| v) // Discard Ok return value
|
|
})
|
|
.and_then(|mut v| {
|
|
let set_fn_name = "set$".to_string() + id;
|
|
|
|
self.call_fn_raw(set_fn_name, vec![this_ptr, v.as_mut()], None, pos)
|
|
})
|
|
}
|
|
_ => Err(EvalAltResult::ErrorDotExpr(inner_lhs.position())),
|
|
},
|
|
|
|
_ => Err(EvalAltResult::ErrorDotExpr(dot_rhs.position())),
|
|
}
|
|
}
|
|
|
|
fn set_dot_val(
|
|
&self,
|
|
scope: &mut Scope,
|
|
dot_lhs: &Expr,
|
|
dot_rhs: &Expr,
|
|
source_val: Dynamic,
|
|
) -> Result<Dynamic, EvalAltResult> {
|
|
match dot_lhs {
|
|
Expr::Identifier(id, pos) => {
|
|
let (sc_idx, mut target) =
|
|
Self::search_scope(scope, id, |x| Ok(x.into_dynamic()), *pos)?;
|
|
let value = self.set_dot_val_helper(target.as_mut(), dot_rhs, source_val);
|
|
|
|
// In case the expression mutated `target`, we need to reassign it because
|
|
// of the above `clone`.
|
|
*scope.get_mut(id, sc_idx) = target;
|
|
|
|
value
|
|
}
|
|
|
|
Expr::Index(id, idx_raw, pos) => {
|
|
let (is_array, sc_idx, idx, mut target) =
|
|
self.indexed_value(scope, id, idx_raw, *pos)?;
|
|
let value = self.set_dot_val_helper(target.as_mut(), dot_rhs, source_val);
|
|
|
|
// In case the expression mutated `target`, we need to reassign it because
|
|
// of the above `clone`.
|
|
if is_array {
|
|
scope.get_mut(id, sc_idx).downcast_mut::<Array>().unwrap()[idx] = target;
|
|
} else {
|
|
Self::str_replace_char(
|
|
scope.get_mut(id, sc_idx).downcast_mut::<String>().unwrap(), // Root is a string
|
|
idx,
|
|
*target.downcast::<char>().unwrap(), // Target should be a char
|
|
);
|
|
}
|
|
|
|
value
|
|
}
|
|
|
|
_ => Err(EvalAltResult::ErrorDotExpr(dot_lhs.position())),
|
|
}
|
|
}
|
|
|
|
fn eval_expr(&self, scope: &mut Scope, expr: &Expr) -> Result<Dynamic, EvalAltResult> {
|
|
match expr {
|
|
Expr::IntegerConstant(i, _) => Ok(Box::new(*i)),
|
|
Expr::FloatConstant(i, _) => Ok(Box::new(*i)),
|
|
Expr::StringConstant(s, _) => Ok(Box::new(s.clone())),
|
|
Expr::CharConstant(c, _) => Ok(Box::new(*c)),
|
|
|
|
Expr::Identifier(id, pos) => scope
|
|
.get(id)
|
|
.map(|(_, _, val)| val)
|
|
.ok_or_else(|| EvalAltResult::ErrorVariableNotFound(id.clone(), *pos)),
|
|
|
|
Expr::Index(id, idx_raw, pos) => self
|
|
.indexed_value(scope, id, idx_raw, *pos)
|
|
.map(|(_, _, _, x)| x),
|
|
|
|
Expr::Assignment(ref id, rhs) => {
|
|
let rhs_val = self.eval_expr(scope, rhs)?;
|
|
|
|
match **id {
|
|
Expr::Identifier(ref name, pos) => {
|
|
if let Some((idx, _, _)) = scope.get(name) {
|
|
*scope.get_mut(name, idx) = rhs_val;
|
|
Ok(Box::new(()) as Dynamic)
|
|
} else {
|
|
Err(EvalAltResult::ErrorVariableNotFound(name.clone(), pos))
|
|
}
|
|
}
|
|
Expr::Index(ref id, ref idx_raw, pos) => {
|
|
let idx_pos = idx_raw.position();
|
|
|
|
let idx = *match self.eval_expr(scope, &idx_raw)?.downcast_ref::<i64>() {
|
|
Some(x) => x,
|
|
_ => return Err(EvalAltResult::ErrorIndexExpr(idx_pos)),
|
|
};
|
|
|
|
let variable = &mut scope
|
|
.iter_mut()
|
|
.rev()
|
|
.filter(|(name, _)| id == name)
|
|
.map(|(_, val)| val)
|
|
.next();
|
|
|
|
let val = match variable {
|
|
Some(v) => v,
|
|
_ => return Err(EvalAltResult::ErrorVariableNotFound(id.clone(), pos)),
|
|
};
|
|
|
|
if let Some(arr) = val.downcast_mut() as Option<&mut Array> {
|
|
if idx < 0 {
|
|
Err(EvalAltResult::ErrorArrayBounds(arr.len(), idx, idx_pos))
|
|
} else if idx as usize >= arr.len() {
|
|
Err(EvalAltResult::ErrorArrayBounds(arr.len(), idx, idx_pos))
|
|
} else {
|
|
arr[idx as usize] = rhs_val;
|
|
Ok(Box::new(()))
|
|
}
|
|
} else if let Some(s) = val.downcast_mut() as Option<&mut String> {
|
|
let s_len = s.chars().count();
|
|
|
|
if idx < 0 {
|
|
Err(EvalAltResult::ErrorStringBounds(s_len, idx, idx_pos))
|
|
} else if idx as usize >= s_len {
|
|
Err(EvalAltResult::ErrorStringBounds(s_len, idx, idx_pos))
|
|
} else {
|
|
Self::str_replace_char(
|
|
s,
|
|
idx as usize,
|
|
*rhs_val.downcast::<char>().unwrap(),
|
|
);
|
|
Ok(Box::new(()))
|
|
}
|
|
} else {
|
|
Err(EvalAltResult::ErrorIndexExpr(idx_pos))
|
|
}
|
|
}
|
|
|
|
Expr::Dot(ref dot_lhs, ref dot_rhs) => {
|
|
self.set_dot_val(scope, dot_lhs, dot_rhs, rhs_val)
|
|
}
|
|
|
|
_ => Err(EvalAltResult::ErrorAssignmentToUnknownLHS(id.position())),
|
|
}
|
|
}
|
|
|
|
Expr::Dot(lhs, rhs) => self.get_dot_val(scope, lhs, rhs),
|
|
|
|
Expr::Array(contents, _) => {
|
|
let mut arr = Vec::new();
|
|
|
|
contents.iter().try_for_each(|item| {
|
|
let arg = self.eval_expr(scope, item)?;
|
|
arr.push(arg);
|
|
Ok(())
|
|
})?;
|
|
|
|
Ok(Box::new(arr))
|
|
}
|
|
|
|
Expr::FunctionCall(fn_name, args, def_value, pos) => self.call_fn_raw(
|
|
fn_name.into(),
|
|
args.iter()
|
|
.map(|expr| self.eval_expr(scope, expr))
|
|
.collect::<Result<Array, _>>()?
|
|
.iter_mut()
|
|
.map(|b| b.as_mut())
|
|
.collect(),
|
|
def_value.as_ref(),
|
|
*pos,
|
|
),
|
|
|
|
Expr::And(lhs, rhs) => Ok(Box::new(
|
|
*self
|
|
.eval_expr(scope, &*lhs)?
|
|
.downcast::<bool>()
|
|
.map_err(|_| {
|
|
EvalAltResult::ErrorBooleanArgMismatch("AND".into(), lhs.position())
|
|
})?
|
|
&& *self
|
|
.eval_expr(scope, &*rhs)?
|
|
.downcast::<bool>()
|
|
.map_err(|_| {
|
|
EvalAltResult::ErrorBooleanArgMismatch("AND".into(), rhs.position())
|
|
})?,
|
|
)),
|
|
|
|
Expr::Or(lhs, rhs) => Ok(Box::new(
|
|
*self
|
|
.eval_expr(scope, &*lhs)?
|
|
.downcast::<bool>()
|
|
.map_err(|_| {
|
|
EvalAltResult::ErrorBooleanArgMismatch("OR".into(), lhs.position())
|
|
})?
|
|
|| *self
|
|
.eval_expr(scope, &*rhs)?
|
|
.downcast::<bool>()
|
|
.map_err(|_| {
|
|
EvalAltResult::ErrorBooleanArgMismatch("OR".into(), rhs.position())
|
|
})?,
|
|
)),
|
|
|
|
Expr::True(_) => Ok(Box::new(true)),
|
|
Expr::False(_) => Ok(Box::new(false)),
|
|
Expr::Unit(_) => Ok(Box::new(())),
|
|
}
|
|
}
|
|
|
|
pub(crate) fn eval_stmt(
|
|
&self,
|
|
scope: &mut Scope,
|
|
stmt: &Stmt,
|
|
) -> Result<Dynamic, EvalAltResult> {
|
|
match stmt {
|
|
Stmt::Expr(expr) => self.eval_expr(scope, expr),
|
|
|
|
Stmt::Block(block) => {
|
|
let prev_len = scope.len();
|
|
let mut last_result: Result<Dynamic, EvalAltResult> = Ok(Box::new(()));
|
|
|
|
for block_stmt in block.iter() {
|
|
last_result = self.eval_stmt(scope, block_stmt);
|
|
|
|
if let Err(x) = last_result {
|
|
last_result = Err(x);
|
|
break;
|
|
}
|
|
}
|
|
|
|
while scope.len() > prev_len {
|
|
scope.pop();
|
|
}
|
|
|
|
last_result
|
|
}
|
|
|
|
Stmt::IfElse(guard, body, else_body) => self
|
|
.eval_expr(scope, guard)?
|
|
.downcast::<bool>()
|
|
.map_err(|_| EvalAltResult::ErrorIfGuard(guard.position()))
|
|
.and_then(|guard_val| {
|
|
if *guard_val {
|
|
self.eval_stmt(scope, body)
|
|
} else if else_body.is_some() {
|
|
self.eval_stmt(scope, else_body.as_ref().unwrap())
|
|
} else {
|
|
Ok(Box::new(()))
|
|
}
|
|
}),
|
|
|
|
Stmt::While(guard, body) => loop {
|
|
match self.eval_expr(scope, guard)?.downcast::<bool>() {
|
|
Ok(guard_val) => {
|
|
if *guard_val {
|
|
match self.eval_stmt(scope, body) {
|
|
Err(EvalAltResult::LoopBreak) => return Ok(Box::new(())),
|
|
Err(x) => return Err(x),
|
|
_ => (),
|
|
}
|
|
} else {
|
|
return Ok(Box::new(()));
|
|
}
|
|
}
|
|
Err(_) => return Err(EvalAltResult::ErrorIfGuard(guard.position())),
|
|
}
|
|
},
|
|
|
|
Stmt::Loop(body) => loop {
|
|
match self.eval_stmt(scope, body) {
|
|
Err(EvalAltResult::LoopBreak) => return Ok(Box::new(())),
|
|
Err(x) => return Err(x),
|
|
_ => (),
|
|
}
|
|
},
|
|
|
|
Stmt::For(name, expr, body) => {
|
|
let arr = self.eval_expr(scope, expr)?;
|
|
let tid = Any::type_id(&*arr);
|
|
|
|
if let Some(iter_fn) = self.type_iterators.get(&tid) {
|
|
scope.push(name.clone(), ());
|
|
let idx = scope.len() - 1;
|
|
|
|
for a in iter_fn(&arr) {
|
|
*scope.get_mut(name, idx) = a;
|
|
|
|
match self.eval_stmt(scope, body) {
|
|
Err(EvalAltResult::LoopBreak) => break,
|
|
Err(x) => return Err(x),
|
|
_ => (),
|
|
}
|
|
}
|
|
scope.pop();
|
|
Ok(Box::new(()))
|
|
} else {
|
|
return Err(EvalAltResult::ErrorFor(expr.position()));
|
|
}
|
|
}
|
|
|
|
Stmt::Break(_) => Err(EvalAltResult::LoopBreak),
|
|
|
|
Stmt::Return(pos) => Err(EvalAltResult::Return(Box::new(()), *pos)),
|
|
|
|
Stmt::ReturnWithVal(a, pos) => {
|
|
let result = self.eval_expr(scope, a)?;
|
|
Err(EvalAltResult::Return(result, *pos))
|
|
}
|
|
|
|
Stmt::Let(name, init, _) => {
|
|
if let Some(v) = init {
|
|
let val = self.eval_expr(scope, v)?;
|
|
scope.push_dynamic(name.clone(), val);
|
|
} else {
|
|
scope.push(name.clone(), ());
|
|
}
|
|
Ok(Box::new(()))
|
|
}
|
|
}
|
|
}
|
|
|
|
pub(crate) fn map_type_name<'a>(&'a self, name: &'a str) -> &'a str {
|
|
self.type_names
|
|
.get(name)
|
|
.map(|s| s.as_str())
|
|
.unwrap_or(name)
|
|
}
|
|
|
|
/// Make a new engine
|
|
pub fn new() -> Engine {
|
|
// User-friendly names for built-in types
|
|
let type_names = [
|
|
("alloc::string::String", "string"),
|
|
(
|
|
"alloc::vec::Vec<alloc::boxed::Box<dyn rhai::any::Any>>",
|
|
"array",
|
|
),
|
|
("alloc::boxed::Box<dyn rhai::any::Any>", "dynamic"),
|
|
]
|
|
.iter()
|
|
.map(|(k, v)| (k.to_string(), v.to_string()))
|
|
.collect();
|
|
|
|
let mut engine = Engine {
|
|
fns: HashMap::new(),
|
|
script_fns: HashMap::new(),
|
|
type_iterators: HashMap::new(),
|
|
type_names,
|
|
on_print: Box::new(|x: &str| println!("{}", x)),
|
|
on_debug: Box::new(|x: &str| println!("{}", x)),
|
|
};
|
|
|
|
engine.register_builtins();
|
|
|
|
engine
|
|
}
|
|
}
|