1486 lines
52 KiB
Rust
1486 lines
52 KiB
Rust
//! Main module defining the script evaluation `Engine`.
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use crate::any::{Any, AnyExt, Dynamic, Variant};
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use crate::parser::{Expr, FnDef, Position, ReturnType, Stmt, INT};
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use crate::result::EvalAltResult;
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use crate::scope::{EntryRef as ScopeSource, EntryType as ScopeEntryType, Scope};
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#[cfg(not(feature = "no_optimize"))]
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use crate::optimize::OptimizationLevel;
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use crate::stdlib::{
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any::{type_name, TypeId},
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borrow::Cow,
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boxed::Box,
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cmp::Ordering,
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collections::HashMap,
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format,
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iter::once,
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string::{String, ToString},
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sync::Arc,
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vec,
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vec::Vec,
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};
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/// An dynamic array of `Dynamic` values.
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#[cfg(not(feature = "no_index"))]
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pub type Array = Vec<Dynamic>;
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/// An dynamic hash map of `Dynamic` values.
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#[cfg(not(feature = "no_object"))]
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pub type Map = HashMap<String, Dynamic>;
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pub type FnCallArgs<'a> = [&'a mut Variant];
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pub type FnAny = dyn Fn(&mut FnCallArgs, Position) -> Result<Dynamic, EvalAltResult>;
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type IteratorFn = dyn Fn(&Dynamic) -> Box<dyn Iterator<Item = Dynamic>>;
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pub const MAX_CALL_STACK_DEPTH: usize = 64;
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pub const KEYWORD_PRINT: &str = "print";
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pub const KEYWORD_DEBUG: &str = "debug";
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pub const KEYWORD_DUMP_AST: &str = "dump_ast";
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pub const KEYWORD_TYPE_OF: &str = "type_of";
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pub const KEYWORD_EVAL: &str = "eval";
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pub const FUNC_TO_STRING: &str = "to_string";
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pub const FUNC_GETTER: &str = "get$";
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pub const FUNC_SETTER: &str = "set$";
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#[derive(Debug, Eq, PartialEq, Hash, Clone, Copy)]
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#[cfg(not(feature = "no_index"))]
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enum IndexSourceType {
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Expression,
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String,
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Array,
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#[cfg(not(feature = "no_object"))]
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Map,
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}
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#[derive(Debug, Eq, PartialEq, Hash, Clone)]
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enum IndexValue {
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Num(usize),
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Str(String),
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}
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impl IndexValue {
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fn from_num(idx: INT) -> Self {
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Self::Num(idx as usize)
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}
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fn from_str(name: String) -> Self {
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Self::Str(name)
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}
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fn as_num(self) -> usize {
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match self {
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Self::Num(n) => n,
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_ => panic!("index value is numeric"),
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}
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}
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fn as_str(self) -> String {
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match self {
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Self::Str(s) => s,
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_ => panic!("index value is string"),
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}
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}
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}
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#[derive(Debug)]
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enum Target<'a> {
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Scope(ScopeSource<'a>),
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Value(&'a mut Variant),
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}
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impl<'a> Target<'a> {
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fn from(value: &'a mut Variant) -> Self {
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Self::Value(value)
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}
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fn from_src(src: ScopeSource<'a>) -> Self {
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Self::Scope(src)
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}
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fn get_mut(self, scope: &'a mut Scope) -> &'a mut Variant {
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match self {
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Self::Value(t) => t,
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Self::Scope(src) => scope.get_mut(src).as_mut(),
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}
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}
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}
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#[derive(Debug, Eq, PartialEq, Hash, Clone)]
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pub struct FnSpec<'a> {
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pub name: Cow<'a, str>,
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pub args: Vec<TypeId>,
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}
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/// A type that holds a library of script-defined functions.
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///
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/// Since script-defined functions have `Dynamic` parameters, functions with the same name
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/// and number of parameters are considered equivalent.
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///
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/// Since the key is a combination of the function name (a String) plus the number of parameters,
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/// we cannot use a `HashMap` because we don't want to clone the function name string just
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/// to search for it.
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///
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/// So instead this is implemented as a sorted list and binary searched.
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#[derive(Debug)]
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pub struct FunctionsLib(Vec<Arc<FnDef>>);
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impl FnDef {
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/// Function to order two FnDef records, for binary search.
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pub fn compare(&self, name: &str, params_len: usize) -> Ordering {
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// First order by name
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match self.name.as_str().cmp(name) {
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// Then by number of parameters
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Ordering::Equal => self.params.len().cmp(¶ms_len),
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order => order,
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}
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}
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}
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impl FunctionsLib {
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/// Create a new `FunctionsLib`.
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pub fn new() -> Self {
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FunctionsLib(Vec::new())
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}
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/// Clear the `FunctionsLib`.
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pub fn clear(&mut self) {
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self.0.clear();
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}
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/// Does a certain function exist in the `FunctionsLib`?
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pub fn has_function(&self, name: &str, params: usize) -> bool {
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self.0.binary_search_by(|f| f.compare(name, params)).is_ok()
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}
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/// Add a function (or replace an existing one) in the `FunctionsLib`.
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pub fn add_or_replace_function(&mut self, fn_def: Arc<FnDef>) {
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match self
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.0
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.binary_search_by(|f| f.compare(&fn_def.name, fn_def.params.len()))
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{
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Ok(n) => self.0[n] = fn_def,
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Err(n) => self.0.insert(n, fn_def),
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}
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}
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/// Get a function definition from the `FunctionsLib`.
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pub fn get_function(&self, name: &str, params: usize) -> Option<Arc<FnDef>> {
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if let Ok(n) = self.0.binary_search_by(|f| f.compare(name, params)) {
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Some(self.0[n].clone())
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} else {
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None
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}
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}
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}
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/// Rhai main scripting engine.
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///
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/// ```
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/// # fn main() -> Result<(), rhai::EvalAltResult> {
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/// use rhai::Engine;
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///
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/// let mut engine = Engine::new();
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///
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/// let result = engine.eval::<i64>("40 + 2")?;
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///
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/// println!("Answer: {}", result); // prints 42
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/// # Ok(())
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/// # }
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/// ```
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pub struct Engine<'e> {
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/// A hashmap containing all compiled functions known to the engine.
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pub(crate) functions: HashMap<FnSpec<'e>, Box<FnAny>>,
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/// A hashmap containing all script-defined functions.
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pub(crate) fn_lib: FunctionsLib,
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/// A hashmap containing all iterators known to the engine.
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pub(crate) type_iterators: HashMap<TypeId, Box<IteratorFn>>,
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/// A hashmap mapping type names to pretty-print names.
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pub(crate) type_names: HashMap<String, String>,
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/// Closure for implementing the `print` command.
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pub(crate) on_print: Box<dyn FnMut(&str) + 'e>,
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/// Closure for implementing the `debug` command.
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pub(crate) on_debug: Box<dyn FnMut(&str) + 'e>,
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/// Optimize the AST after compilation.
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#[cfg(not(feature = "no_optimize"))]
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pub(crate) optimization_level: OptimizationLevel,
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/// Maximum levels of call-stack to prevent infinite recursion.
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pub(crate) max_call_stack_depth: usize,
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}
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impl Default for Engine<'_> {
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fn default() -> Self {
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// User-friendly names for built-in types
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let type_names = [
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#[cfg(not(feature = "no_index"))]
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(type_name::<Array>(), "array"),
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#[cfg(not(feature = "no_object"))]
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(type_name::<Map>(), "map"),
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(type_name::<String>(), "string"),
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(type_name::<Dynamic>(), "dynamic"),
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]
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.iter()
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.map(|(k, v)| ((*k).to_string(), (*v).to_string()))
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.collect();
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// Create the new scripting Engine
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let mut engine = Engine {
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functions: HashMap::new(),
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fn_lib: FunctionsLib::new(),
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type_iterators: HashMap::new(),
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type_names,
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on_print: Box::new(default_print), // default print/debug implementations
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on_debug: Box::new(default_print),
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#[cfg(not(feature = "no_optimize"))]
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#[cfg(not(feature = "optimize_full"))]
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optimization_level: OptimizationLevel::Simple,
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#[cfg(not(feature = "no_optimize"))]
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#[cfg(feature = "optimize_full")]
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optimization_level: OptimizationLevel::Full,
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max_call_stack_depth: MAX_CALL_STACK_DEPTH,
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};
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engine.register_core_lib();
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#[cfg(not(feature = "no_stdlib"))]
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engine.register_stdlib(); // Register the standard library when no_stdlib is not set
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engine
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}
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}
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/// Make getter function
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pub fn make_getter(id: &str) -> String {
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format!("{}{}", FUNC_GETTER, id)
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}
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/// Extract the property name from a getter function name.
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fn extract_prop_from_getter(fn_name: &str) -> Option<&str> {
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if fn_name.starts_with(FUNC_GETTER) {
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Some(&fn_name[FUNC_GETTER.len()..])
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} else {
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None
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}
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}
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/// Make setter function
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pub fn make_setter(id: &str) -> String {
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format!("{}{}", FUNC_SETTER, id)
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}
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/// Extract the property name from a setter function name.
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fn extract_prop_from_setter(fn_name: &str) -> Option<&str> {
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if fn_name.starts_with(FUNC_SETTER) {
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Some(&fn_name[FUNC_SETTER.len()..])
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} else {
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None
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}
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}
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impl Engine<'_> {
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/// Create a new `Engine`
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pub fn new() -> Self {
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Default::default()
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}
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/// Control whether and how the `Engine` will optimize an AST after compilation
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#[cfg(not(feature = "no_optimize"))]
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pub fn set_optimization_level(&mut self, optimization_level: OptimizationLevel) {
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self.optimization_level = optimization_level
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}
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/// Set the maximum levels of function calls allowed for a script in order to avoid
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/// infinite recursion and stack overflows.
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pub fn set_max_call_levels(&mut self, levels: usize) {
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self.max_call_stack_depth = levels
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}
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/// Call a registered function
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#[cfg(not(feature = "no_optimize"))]
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pub(crate) fn call_ext_fn_raw(
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&self,
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fn_name: &str,
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args: &mut FnCallArgs,
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pos: Position,
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) -> Result<Option<Dynamic>, EvalAltResult> {
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let spec = FnSpec {
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name: fn_name.into(),
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args: args.iter().map(|a| Any::type_id(&**a)).collect(),
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};
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// Search built-in's and external functions
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if let Some(func) = self.functions.get(&spec) {
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// Run external function
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Ok(Some(func(args, pos)?))
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} else {
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Ok(None)
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}
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}
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/// Universal method for calling functions either registered with the `Engine` or written in Rhai
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pub(crate) fn call_fn_raw(
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&mut self,
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fn_name: &str,
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args: &mut FnCallArgs,
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def_val: Option<&Dynamic>,
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pos: Position,
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level: usize,
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) -> Result<Dynamic, EvalAltResult> {
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// First search in script-defined functions (can override built-in)
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if let Some(fn_def) = self.fn_lib.get_function(fn_name, args.len()) {
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let mut scope = Scope::new();
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scope.extend(
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// Put arguments into scope as variables
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fn_def
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.params
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.iter()
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.zip(args.iter().map(|x| (*x).into_dynamic()))
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.map(|(name, value)| (name, ScopeEntryType::Normal, value)),
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);
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// Evaluate the function at one higher level of call depth
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return self
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.eval_stmt(&mut scope, &fn_def.body, level + 1)
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.or_else(|err| match err {
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// Convert return statement to return value
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EvalAltResult::Return(x, _) => Ok(x),
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err => Err(err.set_position(pos)),
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});
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}
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let spec = FnSpec {
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name: fn_name.into(),
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args: args.iter().map(|a| Any::type_id(&**a)).collect(),
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};
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// Argument must be a string
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fn cast_to_string(r: &Variant, pos: Position) -> Result<&str, EvalAltResult> {
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r.downcast_ref::<String>()
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.map(String::as_str)
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.ok_or_else(|| EvalAltResult::ErrorMismatchOutputType(r.type_name().into(), pos))
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}
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// Search built-in's and external functions
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if let Some(func) = self.functions.get(&spec) {
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// Run external function
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let result = func(args, pos)?;
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// See if the function match print/debug (which requires special processing)
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return Ok(match fn_name {
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KEYWORD_PRINT => {
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self.on_print.as_mut()(cast_to_string(result.as_ref(), pos)?).into_dynamic()
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}
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KEYWORD_DEBUG => {
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self.on_debug.as_mut()(cast_to_string(result.as_ref(), pos)?).into_dynamic()
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}
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_ => result,
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});
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}
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if let Some(prop) = extract_prop_from_getter(fn_name) {
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#[cfg(not(feature = "no_object"))]
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{
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// Map property access
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if let Some(map) = args[0].downcast_ref::<Map>() {
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return Ok(map.get(prop).cloned().unwrap_or_else(|| ().into_dynamic()));
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}
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}
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// Getter function not found
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return Err(EvalAltResult::ErrorDotExpr(
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format!("- property '{}' unknown or write-only", prop),
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pos,
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));
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}
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if let Some(prop) = extract_prop_from_setter(fn_name) {
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#[cfg(not(feature = "no_object"))]
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{
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let value = args[1].into_dynamic();
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// Map property update
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if let Some(map) = args[0].downcast_mut::<Map>() {
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map.insert(prop.to_string(), value);
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return Ok(().into_dynamic());
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}
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}
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|
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// Setter function not found
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return Err(EvalAltResult::ErrorDotExpr(
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format!("- property '{}' unknown or read-only", prop),
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pos,
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));
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}
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if let Some(val) = def_val {
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// Return default value
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return Ok(val.clone());
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}
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|
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// Raise error
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let types_list: Vec<_> = 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();
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Err(EvalAltResult::ErrorFunctionNotFound(
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format!("{} ({})", fn_name, types_list.join(", ")),
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pos,
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))
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}
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|
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/// Chain-evaluate a dot setter.
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#[cfg(not(feature = "no_object"))]
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fn get_dot_val_helper(
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&mut self,
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scope: &mut Scope,
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target: Target,
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dot_rhs: &Expr,
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level: usize,
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) -> Result<Dynamic, EvalAltResult> {
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match dot_rhs {
|
|
// xxx.fn_name(args)
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Expr::FunctionCall(fn_name, arg_expr_list, def_val, pos) => {
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let mut values = arg_expr_list
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.iter()
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.map(|arg_expr| self.eval_expr(scope, arg_expr, level))
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.collect::<Result<Vec<_>, _>>()?;
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|
|
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let this_ptr = target.get_mut(scope);
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|
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let mut arg_values: Vec<_> = once(this_ptr)
|
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.chain(values.iter_mut().map(Dynamic::as_mut))
|
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.collect();
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|
|
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self.call_fn_raw(fn_name, &mut arg_values, def_val.as_ref(), *pos, 0)
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}
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|
|
|
// xxx.id
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Expr::Property(id, pos) => {
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let this_ptr = target.get_mut(scope);
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self.call_fn_raw(&make_getter(id), &mut [this_ptr], None, *pos, 0)
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}
|
|
|
|
// xxx.idx_lhs[idx_expr]
|
|
#[cfg(not(feature = "no_index"))]
|
|
Expr::Index(idx_lhs, idx_expr, op_pos) => {
|
|
let value = match idx_lhs.as_ref() {
|
|
// xxx.id[idx_expr]
|
|
Expr::Property(id, pos) => {
|
|
let this_ptr = target.get_mut(scope);
|
|
self.call_fn_raw(&make_getter(id), &mut [this_ptr], None, *pos, 0)?
|
|
}
|
|
// xxx.???[???][idx_expr]
|
|
Expr::Index(_, _, _) => {
|
|
self.get_dot_val_helper(scope, target, idx_lhs, level)?
|
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}
|
|
// Syntax error
|
|
_ => {
|
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return Err(EvalAltResult::ErrorDotExpr(
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"".to_string(),
|
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dot_rhs.position(),
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))
|
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}
|
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};
|
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|
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self.get_indexed_value(scope, &value, idx_expr, *op_pos, level)
|
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.map(|(val, _, _)| val)
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}
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|
|
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// xxx.dot_lhs.rhs
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Expr::Dot(dot_lhs, rhs, _) => match dot_lhs.as_ref() {
|
|
// xxx.id.rhs
|
|
Expr::Property(id, pos) => {
|
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let this_ptr = target.get_mut(scope);
|
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self.call_fn_raw(&make_getter(id), &mut [this_ptr], None, *pos, 0)
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.and_then(|mut val| {
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self.get_dot_val_helper(scope, Target::from(val.as_mut()), rhs, level)
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})
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}
|
|
// xxx.idx_lhs[idx_expr].rhs
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|
#[cfg(not(feature = "no_index"))]
|
|
Expr::Index(idx_lhs, idx_expr, op_pos) => {
|
|
let val = match idx_lhs.as_ref() {
|
|
// xxx.id[idx_expr].rhs
|
|
Expr::Property(id, pos) => {
|
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let this_ptr = target.get_mut(scope);
|
|
self.call_fn_raw(&make_getter(id), &mut [this_ptr], None, *pos, 0)?
|
|
}
|
|
// xxx.???[???][idx_expr].rhs
|
|
Expr::Index(_, _, _) => {
|
|
self.get_dot_val_helper(scope, target, idx_lhs, level)?
|
|
}
|
|
// Syntax error
|
|
_ => {
|
|
return Err(EvalAltResult::ErrorDotExpr(
|
|
"".to_string(),
|
|
dot_rhs.position(),
|
|
))
|
|
}
|
|
};
|
|
|
|
self.get_indexed_value(scope, &val, idx_expr, *op_pos, level)
|
|
.and_then(|(mut val, _, _)| {
|
|
self.get_dot_val_helper(scope, Target::from(val.as_mut()), rhs, level)
|
|
})
|
|
}
|
|
// Syntax error
|
|
_ => Err(EvalAltResult::ErrorDotExpr(
|
|
"".to_string(),
|
|
dot_lhs.position(),
|
|
)),
|
|
},
|
|
|
|
// Syntax error
|
|
_ => Err(EvalAltResult::ErrorDotExpr(
|
|
"".to_string(),
|
|
dot_rhs.position(),
|
|
)),
|
|
}
|
|
}
|
|
|
|
/// Evaluate a dot chain getter
|
|
#[cfg(not(feature = "no_object"))]
|
|
fn get_dot_val(
|
|
&mut self,
|
|
scope: &mut Scope,
|
|
dot_lhs: &Expr,
|
|
dot_rhs: &Expr,
|
|
level: usize,
|
|
) -> Result<Dynamic, EvalAltResult> {
|
|
match dot_lhs {
|
|
// id.???
|
|
Expr::Variable(id, pos) => {
|
|
let (entry, _) = Self::search_scope(scope, id, *pos)?;
|
|
|
|
// Avoid referencing scope which is used below as mut
|
|
let entry = ScopeSource { name: id, ..entry };
|
|
|
|
// This is a variable property access (potential function call).
|
|
// Use a direct index into `scope` to directly mutate the variable value.
|
|
self.get_dot_val_helper(scope, Target::from_src(entry), dot_rhs, level)
|
|
}
|
|
|
|
// idx_lhs[idx_expr].???
|
|
#[cfg(not(feature = "no_index"))]
|
|
Expr::Index(idx_lhs, idx_expr, op_pos) => {
|
|
let (idx_src_type, src, idx, mut val) =
|
|
self.eval_index_expr(scope, idx_lhs, idx_expr, *op_pos, level)?;
|
|
let value =
|
|
self.get_dot_val_helper(scope, Target::from(val.as_mut()), dot_rhs, level);
|
|
|
|
// In case the expression mutated `target`, we need to update it back into the scope because it is cloned.
|
|
if let Some(src) = src {
|
|
match src.typ {
|
|
ScopeEntryType::Constant => {
|
|
return Err(EvalAltResult::ErrorAssignmentToConstant(
|
|
src.name.to_string(),
|
|
idx_lhs.position(),
|
|
));
|
|
}
|
|
ScopeEntryType::Normal => {
|
|
Self::update_indexed_var_in_scope(
|
|
idx_src_type,
|
|
scope,
|
|
src,
|
|
idx,
|
|
(val, dot_rhs.position()),
|
|
)?;
|
|
}
|
|
}
|
|
}
|
|
|
|
value
|
|
}
|
|
|
|
// {expr}.???
|
|
expr => {
|
|
let mut val = self.eval_expr(scope, expr, level)?;
|
|
self.get_dot_val_helper(scope, Target::from(val.as_mut()), dot_rhs, level)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Search for a variable within the scope, returning its value and index inside the Scope
|
|
fn search_scope<'a>(
|
|
scope: &'a Scope,
|
|
id: &str,
|
|
begin: Position,
|
|
) -> Result<(ScopeSource<'a>, Dynamic), EvalAltResult> {
|
|
scope
|
|
.get(id)
|
|
.ok_or_else(|| EvalAltResult::ErrorVariableNotFound(id.into(), begin))
|
|
}
|
|
|
|
/// Get the value at the indexed position of a base type
|
|
#[cfg(not(feature = "no_index"))]
|
|
fn get_indexed_value(
|
|
&mut self,
|
|
scope: &mut Scope,
|
|
val: &Dynamic,
|
|
idx_expr: &Expr,
|
|
op_pos: Position,
|
|
level: usize,
|
|
) -> Result<(Dynamic, IndexSourceType, IndexValue), EvalAltResult> {
|
|
let idx_pos = idx_expr.position();
|
|
|
|
// val_array[idx]
|
|
if let Some(arr) = val.downcast_ref::<Array>() {
|
|
let idx = *self
|
|
.eval_expr(scope, idx_expr, level)?
|
|
.downcast::<INT>()
|
|
.map_err(|_| EvalAltResult::ErrorNumericIndexExpr(idx_expr.position()))?;
|
|
|
|
return if idx >= 0 {
|
|
arr.get(idx as usize)
|
|
.cloned()
|
|
.map(|v| (v, IndexSourceType::Array, IndexValue::from_num(idx)))
|
|
.ok_or_else(|| EvalAltResult::ErrorArrayBounds(arr.len(), idx, idx_pos))
|
|
} else {
|
|
Err(EvalAltResult::ErrorArrayBounds(arr.len(), idx, idx_pos))
|
|
};
|
|
}
|
|
|
|
#[cfg(not(feature = "no_object"))]
|
|
{
|
|
// val_map[idx]
|
|
if let Some(map) = val.downcast_ref::<Map>() {
|
|
let idx = *self
|
|
.eval_expr(scope, idx_expr, level)?
|
|
.downcast::<String>()
|
|
.map_err(|_| EvalAltResult::ErrorStringIndexExpr(idx_expr.position()))?;
|
|
|
|
return Ok((
|
|
map.get(&idx).cloned().unwrap_or_else(|| ().into_dynamic()),
|
|
IndexSourceType::Map,
|
|
IndexValue::from_str(idx),
|
|
));
|
|
}
|
|
}
|
|
|
|
// val_string[idx]
|
|
if let Some(s) = val.downcast_ref::<String>() {
|
|
let idx = *self
|
|
.eval_expr(scope, idx_expr, level)?
|
|
.downcast::<INT>()
|
|
.map_err(|_| EvalAltResult::ErrorNumericIndexExpr(idx_expr.position()))?;
|
|
|
|
return if idx >= 0 {
|
|
s.chars()
|
|
.nth(idx as usize)
|
|
.map(|ch| {
|
|
(
|
|
ch.into_dynamic(),
|
|
IndexSourceType::String,
|
|
IndexValue::from_num(idx),
|
|
)
|
|
})
|
|
.ok_or_else(|| {
|
|
EvalAltResult::ErrorStringBounds(s.chars().count(), idx, idx_pos)
|
|
})
|
|
} else {
|
|
Err(EvalAltResult::ErrorStringBounds(
|
|
s.chars().count(),
|
|
idx,
|
|
idx_pos,
|
|
))
|
|
};
|
|
}
|
|
|
|
// Error - cannot be indexed
|
|
Err(EvalAltResult::ErrorIndexingType(
|
|
self.map_type_name(val.type_name()).to_string(),
|
|
op_pos,
|
|
))
|
|
}
|
|
|
|
/// Evaluate an index expression
|
|
#[cfg(not(feature = "no_index"))]
|
|
fn eval_index_expr<'a>(
|
|
&mut self,
|
|
scope: &mut Scope,
|
|
lhs: &'a Expr,
|
|
idx_expr: &Expr,
|
|
op_pos: Position,
|
|
level: usize,
|
|
) -> Result<
|
|
(
|
|
IndexSourceType,
|
|
Option<ScopeSource<'a>>,
|
|
IndexValue,
|
|
Dynamic,
|
|
),
|
|
EvalAltResult,
|
|
> {
|
|
match lhs {
|
|
// id[idx_expr]
|
|
Expr::Variable(id, _) => {
|
|
let (
|
|
ScopeSource {
|
|
typ: src_type,
|
|
index: src_idx,
|
|
..
|
|
},
|
|
val,
|
|
) = Self::search_scope(scope, &id, lhs.position())?;
|
|
|
|
let (val, idx_src_type, idx) =
|
|
self.get_indexed_value(scope, &val, idx_expr, op_pos, level)?;
|
|
|
|
Ok((
|
|
idx_src_type,
|
|
Some(ScopeSource {
|
|
name: &id,
|
|
typ: src_type,
|
|
index: src_idx,
|
|
}),
|
|
idx,
|
|
val,
|
|
))
|
|
}
|
|
|
|
// (expr)[idx_expr]
|
|
expr => {
|
|
let val = self.eval_expr(scope, expr, level)?;
|
|
|
|
self.get_indexed_value(scope, &val, idx_expr, op_pos, level)
|
|
.map(|(val, _, idx)| (IndexSourceType::Expression, None, idx, val))
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Replace a character at an index position in a mutable string
|
|
#[cfg(not(feature = "no_index"))]
|
|
fn str_replace_char(s: &mut String, idx: usize, new_ch: char) {
|
|
let mut chars: Vec<char> = s.chars().collect();
|
|
let ch = *chars.get(idx).expect("string index out of bounds");
|
|
|
|
// See if changed - if so, update the String
|
|
if ch != new_ch {
|
|
chars[idx] = new_ch;
|
|
s.clear();
|
|
chars.iter().for_each(|&ch| s.push(ch));
|
|
}
|
|
}
|
|
|
|
/// Update the value at an index position in a variable inside the scope
|
|
#[cfg(not(feature = "no_index"))]
|
|
fn update_indexed_var_in_scope(
|
|
idx_src_type: IndexSourceType,
|
|
scope: &mut Scope,
|
|
src: ScopeSource,
|
|
idx: IndexValue,
|
|
new_val: (Dynamic, Position),
|
|
) -> Result<Dynamic, EvalAltResult> {
|
|
match idx_src_type {
|
|
// array_id[idx] = val
|
|
IndexSourceType::Array => {
|
|
let arr = scope.get_mut_by_type::<Array>(src);
|
|
arr[idx.as_num()] = new_val.0;
|
|
Ok(().into_dynamic())
|
|
}
|
|
|
|
// map_id[idx] = val
|
|
#[cfg(not(feature = "no_object"))]
|
|
IndexSourceType::Map => {
|
|
let arr = scope.get_mut_by_type::<Map>(src);
|
|
arr.insert(idx.as_str(), new_val.0);
|
|
Ok(().into_dynamic())
|
|
}
|
|
|
|
// string_id[idx] = val
|
|
IndexSourceType::String => {
|
|
let s = scope.get_mut_by_type::<String>(src);
|
|
let pos = new_val.1;
|
|
// Value must be a character
|
|
let ch = *new_val
|
|
.0
|
|
.downcast::<char>()
|
|
.map_err(|_| EvalAltResult::ErrorCharMismatch(pos))?;
|
|
Self::str_replace_char(s, idx.as_num(), ch);
|
|
Ok(().into_dynamic())
|
|
}
|
|
|
|
IndexSourceType::Expression => panic!("expression cannot be indexed for update"),
|
|
}
|
|
}
|
|
|
|
/// Update the value at an index position
|
|
#[cfg(not(feature = "no_index"))]
|
|
fn update_indexed_value(
|
|
mut target: Dynamic,
|
|
idx: IndexValue,
|
|
new_val: Dynamic,
|
|
pos: Position,
|
|
) -> Result<Dynamic, EvalAltResult> {
|
|
if let Some(arr) = target.downcast_mut::<Array>() {
|
|
arr[idx.as_num()] = new_val;
|
|
return Ok(target);
|
|
}
|
|
|
|
#[cfg(not(feature = "no_object"))]
|
|
{
|
|
if let Some(map) = target.downcast_mut::<Map>() {
|
|
map.insert(idx.as_str(), new_val);
|
|
return Ok(target);
|
|
}
|
|
}
|
|
|
|
if let Some(s) = target.downcast_mut::<String>() {
|
|
// Value must be a character
|
|
let ch = *new_val
|
|
.downcast::<char>()
|
|
.map_err(|_| EvalAltResult::ErrorCharMismatch(pos))?;
|
|
Self::str_replace_char(s, idx.as_num(), ch);
|
|
return Ok(target);
|
|
}
|
|
|
|
// All other variable types should be an error
|
|
panic!("array, map or string source type expected for indexing")
|
|
}
|
|
|
|
/// Chain-evaluate a dot setter
|
|
#[cfg(not(feature = "no_object"))]
|
|
fn set_dot_val_helper(
|
|
&mut self,
|
|
scope: &mut Scope,
|
|
this_ptr: &mut Variant,
|
|
dot_rhs: &Expr,
|
|
new_val: (&mut Dynamic, Position),
|
|
level: usize,
|
|
) -> Result<Dynamic, EvalAltResult> {
|
|
match dot_rhs {
|
|
// xxx.id
|
|
Expr::Property(id, pos) => {
|
|
let mut args = [this_ptr, new_val.0.as_mut()];
|
|
self.call_fn_raw(&make_setter(id), &mut args, None, *pos, 0)
|
|
}
|
|
|
|
// xxx.lhs[idx_expr]
|
|
// TODO - Allow chaining of indexing!
|
|
#[cfg(not(feature = "no_index"))]
|
|
Expr::Index(lhs, idx_expr, op_pos) => match lhs.as_ref() {
|
|
// xxx.id[idx_expr]
|
|
Expr::Property(id, pos) => self
|
|
.call_fn_raw(&make_getter(id), &mut [this_ptr], None, *pos, 0)
|
|
.and_then(|val| {
|
|
let (_, _, idx) =
|
|
self.get_indexed_value(scope, &val, idx_expr, *op_pos, level)?;
|
|
|
|
Self::update_indexed_value(val, idx, new_val.0.clone(), new_val.1)
|
|
})
|
|
.and_then(|mut val| {
|
|
let mut args = [this_ptr, val.as_mut()];
|
|
self.call_fn_raw(&make_setter(id), &mut args, None, *pos, 0)
|
|
}),
|
|
|
|
// All others - syntax error for setters chain
|
|
_ => Err(EvalAltResult::ErrorDotExpr(
|
|
"for assignment".to_string(),
|
|
*op_pos,
|
|
)),
|
|
},
|
|
|
|
// xxx.lhs.{...}
|
|
Expr::Dot(lhs, rhs, _) => match lhs.as_ref() {
|
|
// xxx.id.rhs
|
|
Expr::Property(id, pos) => {
|
|
self.call_fn_raw(&make_getter(id), &mut [this_ptr], None, *pos, 0)
|
|
.and_then(|mut val| {
|
|
self.set_dot_val_helper(scope, val.as_mut(), rhs, new_val, level)
|
|
.map(|_| val) // Discard Ok return value
|
|
})
|
|
.and_then(|mut val| {
|
|
let mut args = [this_ptr, val.as_mut()];
|
|
self.call_fn_raw(&make_setter(id), &mut args, None, *pos, 0)
|
|
})
|
|
}
|
|
|
|
// xxx.lhs[idx_expr].rhs
|
|
// TODO - Allow chaining of indexing!
|
|
#[cfg(not(feature = "no_index"))]
|
|
Expr::Index(lhs, idx_expr, op_pos) => match lhs.as_ref() {
|
|
// xxx.id[idx_expr].rhs
|
|
Expr::Property(id, pos) => {
|
|
self.call_fn_raw(&make_getter(id), &mut [this_ptr], None, *pos, 0)
|
|
.and_then(|v| {
|
|
let (mut value, _, idx) =
|
|
self.get_indexed_value(scope, &v, idx_expr, *op_pos, level)?;
|
|
|
|
let val_pos = new_val.1;
|
|
let this_ptr = value.as_mut();
|
|
self.set_dot_val_helper(scope, this_ptr, rhs, new_val, level)?;
|
|
|
|
// In case the expression mutated `target`, we need to update it back into the scope because it is cloned.
|
|
Self::update_indexed_value(v, idx, value, val_pos)
|
|
})
|
|
.and_then(|mut v| {
|
|
self.call_fn_raw(
|
|
&make_setter(id),
|
|
&mut [this_ptr, v.as_mut()],
|
|
None,
|
|
*pos,
|
|
0,
|
|
)
|
|
})
|
|
}
|
|
|
|
// All others - syntax error for setters chain
|
|
_ => Err(EvalAltResult::ErrorDotExpr(
|
|
"for assignment".to_string(),
|
|
*op_pos,
|
|
)),
|
|
},
|
|
|
|
// All others - syntax error for setters chain
|
|
_ => Err(EvalAltResult::ErrorDotExpr(
|
|
"for assignment".to_string(),
|
|
lhs.position(),
|
|
)),
|
|
},
|
|
|
|
// Syntax error
|
|
_ => Err(EvalAltResult::ErrorDotExpr(
|
|
"for assignment".to_string(),
|
|
dot_rhs.position(),
|
|
)),
|
|
}
|
|
}
|
|
|
|
// Evaluate a dot chain setter
|
|
#[cfg(not(feature = "no_object"))]
|
|
fn set_dot_val(
|
|
&mut self,
|
|
scope: &mut Scope,
|
|
dot_lhs: &Expr,
|
|
dot_rhs: &Expr,
|
|
new_val: (&mut Dynamic, Position),
|
|
op_pos: Position,
|
|
level: usize,
|
|
) -> Result<Dynamic, EvalAltResult> {
|
|
match dot_lhs {
|
|
// id.???
|
|
Expr::Variable(id, pos) => {
|
|
let (entry, mut target) = Self::search_scope(scope, id, *pos)?;
|
|
|
|
match entry.typ {
|
|
ScopeEntryType::Constant => Err(EvalAltResult::ErrorAssignmentToConstant(
|
|
id.to_string(),
|
|
op_pos,
|
|
)),
|
|
_ => {
|
|
// Avoid referencing scope which is used below as mut
|
|
let entry = ScopeSource { name: id, ..entry };
|
|
let this_ptr = target.as_mut();
|
|
let value =
|
|
self.set_dot_val_helper(scope, this_ptr, dot_rhs, new_val, level);
|
|
|
|
// In case the expression mutated `target`, we need to update it back into the scope because it is cloned.
|
|
*scope.get_mut(entry) = target;
|
|
|
|
value
|
|
}
|
|
}
|
|
}
|
|
|
|
// lhs[idx_expr].???
|
|
// TODO - Allow chaining of indexing!
|
|
#[cfg(not(feature = "no_index"))]
|
|
Expr::Index(lhs, idx_expr, op_pos) => {
|
|
let (idx_src_type, src, idx, mut target) =
|
|
self.eval_index_expr(scope, lhs, idx_expr, *op_pos, level)?;
|
|
let val_pos = new_val.1;
|
|
let this_ptr = target.as_mut();
|
|
let value = self.set_dot_val_helper(scope, this_ptr, dot_rhs, new_val, level);
|
|
|
|
// In case the expression mutated `target`, we need to update it back into the scope because it is cloned.
|
|
if let Some(src) = src {
|
|
match src.typ {
|
|
ScopeEntryType::Constant => {
|
|
return Err(EvalAltResult::ErrorAssignmentToConstant(
|
|
src.name.to_string(),
|
|
lhs.position(),
|
|
));
|
|
}
|
|
ScopeEntryType::Normal => {
|
|
Self::update_indexed_var_in_scope(
|
|
idx_src_type,
|
|
scope,
|
|
src,
|
|
idx,
|
|
(target, val_pos),
|
|
)?;
|
|
}
|
|
}
|
|
}
|
|
|
|
value
|
|
}
|
|
|
|
// Syntax error
|
|
_ => Err(EvalAltResult::ErrorDotExpr(
|
|
"for assignment".to_string(),
|
|
dot_lhs.position(),
|
|
)),
|
|
}
|
|
}
|
|
|
|
/// Evaluate an expression
|
|
fn eval_expr(
|
|
&mut self,
|
|
scope: &mut Scope,
|
|
expr: &Expr,
|
|
level: usize,
|
|
) -> Result<Dynamic, EvalAltResult> {
|
|
match expr {
|
|
#[cfg(not(feature = "no_float"))]
|
|
Expr::FloatConstant(f, _) => Ok(f.into_dynamic()),
|
|
|
|
Expr::IntegerConstant(i, _) => Ok(i.into_dynamic()),
|
|
Expr::StringConstant(s, _) => Ok(s.into_dynamic()),
|
|
Expr::CharConstant(c, _) => Ok(c.into_dynamic()),
|
|
Expr::Variable(id, pos) => Self::search_scope(scope, id, *pos).map(|(_, val)| val),
|
|
Expr::Property(_, _) => panic!("unexpected property."),
|
|
|
|
// lhs[idx_expr]
|
|
#[cfg(not(feature = "no_index"))]
|
|
Expr::Index(lhs, idx_expr, op_pos) => self
|
|
.eval_index_expr(scope, lhs, idx_expr, *op_pos, level)
|
|
.map(|(_, _, _, x)| x),
|
|
|
|
// Statement block
|
|
Expr::Stmt(stmt, _) => self.eval_stmt(scope, stmt, level),
|
|
|
|
// lhs = rhs
|
|
Expr::Assignment(lhs, rhs, op_pos) => {
|
|
let mut rhs_val = self.eval_expr(scope, rhs, level)?;
|
|
|
|
match lhs.as_ref() {
|
|
// name = rhs
|
|
Expr::Variable(name, pos) => match scope
|
|
.get(name)
|
|
.ok_or_else(|| EvalAltResult::ErrorVariableNotFound(name.clone(), *pos))?
|
|
.0
|
|
{
|
|
entry
|
|
@
|
|
ScopeSource {
|
|
typ: ScopeEntryType::Normal,
|
|
..
|
|
} => {
|
|
// Avoid referencing scope which is used below as mut
|
|
let entry = ScopeSource { name, ..entry };
|
|
|
|
*scope.get_mut(entry) = rhs_val.clone();
|
|
Ok(rhs_val)
|
|
}
|
|
ScopeSource {
|
|
typ: ScopeEntryType::Constant,
|
|
..
|
|
} => Err(EvalAltResult::ErrorAssignmentToConstant(
|
|
name.to_string(),
|
|
*op_pos,
|
|
)),
|
|
},
|
|
|
|
// idx_lhs[idx_expr] = rhs
|
|
#[cfg(not(feature = "no_index"))]
|
|
Expr::Index(idx_lhs, idx_expr, op_pos) => {
|
|
let (idx_src_type, src, idx, _) =
|
|
self.eval_index_expr(scope, idx_lhs, idx_expr, *op_pos, level)?;
|
|
|
|
if let Some(src) = src {
|
|
match src.typ {
|
|
ScopeEntryType::Constant => {
|
|
Err(EvalAltResult::ErrorAssignmentToConstant(
|
|
src.name.to_string(),
|
|
idx_lhs.position(),
|
|
))
|
|
}
|
|
ScopeEntryType::Normal => Ok(Self::update_indexed_var_in_scope(
|
|
idx_src_type,
|
|
scope,
|
|
src,
|
|
idx,
|
|
(rhs_val, rhs.position()),
|
|
)?),
|
|
}
|
|
} else {
|
|
Err(EvalAltResult::ErrorAssignmentToUnknownLHS(
|
|
idx_lhs.position(),
|
|
))
|
|
}
|
|
}
|
|
|
|
// dot_lhs.dot_rhs = rhs
|
|
#[cfg(not(feature = "no_object"))]
|
|
Expr::Dot(dot_lhs, dot_rhs, _) => self.set_dot_val(
|
|
scope,
|
|
dot_lhs,
|
|
dot_rhs,
|
|
(&mut rhs_val, rhs.position()),
|
|
*op_pos,
|
|
level,
|
|
),
|
|
|
|
// Error assignment to constant
|
|
expr if expr.is_constant() => Err(EvalAltResult::ErrorAssignmentToConstant(
|
|
expr.get_constant_str(),
|
|
lhs.position(),
|
|
)),
|
|
|
|
// Syntax error
|
|
_ => Err(EvalAltResult::ErrorAssignmentToUnknownLHS(lhs.position())),
|
|
}
|
|
}
|
|
|
|
#[cfg(not(feature = "no_object"))]
|
|
Expr::Dot(lhs, rhs, _) => self.get_dot_val(scope, lhs, rhs, level),
|
|
|
|
#[cfg(not(feature = "no_index"))]
|
|
Expr::Array(contents, _) => {
|
|
let mut arr = Array::new();
|
|
|
|
contents.into_iter().try_for_each(|item| {
|
|
self.eval_expr(scope, item, level).map(|val| arr.push(val))
|
|
})?;
|
|
|
|
Ok(Box::new(arr))
|
|
}
|
|
|
|
#[cfg(not(feature = "no_object"))]
|
|
Expr::Map(contents, _) => {
|
|
let mut map = Map::new();
|
|
|
|
contents.into_iter().try_for_each(|item| {
|
|
self.eval_expr(scope, &item.1, level).map(|val| {
|
|
map.insert(item.0.clone(), val);
|
|
})
|
|
})?;
|
|
|
|
Ok(Box::new(map))
|
|
}
|
|
|
|
Expr::FunctionCall(fn_name, args_expr_list, def_val, pos) => {
|
|
// Has a system function an override?
|
|
fn has_override(engine: &Engine, name: &str) -> bool {
|
|
let spec = FnSpec {
|
|
name: name.into(),
|
|
args: vec![TypeId::of::<String>()],
|
|
};
|
|
|
|
engine.functions.contains_key(&spec) || engine.fn_lib.has_function(name, 1)
|
|
}
|
|
|
|
match fn_name.as_str() {
|
|
// Dump AST
|
|
KEYWORD_DUMP_AST => {
|
|
let pos = if args_expr_list.is_empty() {
|
|
*pos
|
|
} else {
|
|
args_expr_list[0].position()
|
|
};
|
|
|
|
// Change the argument to a debug dump of the expressions
|
|
let mut result = args_expr_list
|
|
.iter()
|
|
.map(|expr| format!("{:#?}", expr))
|
|
.collect::<Vec<_>>()
|
|
.join("\n")
|
|
.into_dynamic();
|
|
|
|
// Redirect call to `print`
|
|
self.call_fn_raw(KEYWORD_PRINT, &mut [result.as_mut()], None, pos, level)
|
|
}
|
|
|
|
// type_of
|
|
KEYWORD_TYPE_OF
|
|
if args_expr_list.len() == 1 && !has_override(self, KEYWORD_TYPE_OF) =>
|
|
{
|
|
let r = self.eval_expr(scope, &args_expr_list[0], level)?;
|
|
Ok(self
|
|
.map_type_name((*r).type_name())
|
|
.to_string()
|
|
.into_dynamic())
|
|
}
|
|
|
|
// eval
|
|
KEYWORD_EVAL
|
|
if args_expr_list.len() == 1 && !has_override(self, KEYWORD_EVAL) =>
|
|
{
|
|
let pos = args_expr_list[0].position();
|
|
let r = self.eval_expr(scope, &args_expr_list[0], level)?;
|
|
|
|
let script =
|
|
r.downcast_ref::<String>()
|
|
.map(String::as_str)
|
|
.ok_or_else(|| {
|
|
EvalAltResult::ErrorMismatchOutputType(
|
|
r.type_name().into(),
|
|
pos,
|
|
)
|
|
})?;
|
|
|
|
#[cfg(not(feature = "no_optimize"))]
|
|
let ast = {
|
|
let orig_optimization_level = self.optimization_level;
|
|
|
|
self.set_optimization_level(OptimizationLevel::None);
|
|
let ast = self.compile(script);
|
|
self.set_optimization_level(orig_optimization_level);
|
|
|
|
ast.map_err(EvalAltResult::ErrorParsing)?
|
|
};
|
|
|
|
#[cfg(feature = "no_optimize")]
|
|
let ast = self.compile(script).map_err(EvalAltResult::ErrorParsing)?;
|
|
|
|
Ok(self
|
|
.eval_ast_with_scope_raw(scope, true, &ast)
|
|
.map_err(|err| err.set_position(pos))?)
|
|
}
|
|
|
|
// Normal function call
|
|
_ => {
|
|
let mut values = args_expr_list
|
|
.iter()
|
|
.map(|expr| self.eval_expr(scope, expr, level))
|
|
.collect::<Result<Vec<_>, _>>()?;
|
|
|
|
let mut arg_values: Vec<_> =
|
|
values.iter_mut().map(Dynamic::as_mut).collect();
|
|
|
|
self.call_fn_raw(fn_name, &mut arg_values, def_val.as_ref(), *pos, level)
|
|
}
|
|
}
|
|
}
|
|
|
|
Expr::And(lhs, rhs) => Ok(Box::new(
|
|
*self
|
|
.eval_expr(scope, &*lhs, level)?
|
|
.downcast::<bool>()
|
|
.map_err(|_| {
|
|
EvalAltResult::ErrorBooleanArgMismatch("AND".into(), lhs.position())
|
|
})?
|
|
&& // Short-circuit using &&
|
|
*self
|
|
.eval_expr(scope, &*rhs, level)?
|
|
.downcast::<bool>()
|
|
.map_err(|_| {
|
|
EvalAltResult::ErrorBooleanArgMismatch("AND".into(), rhs.position())
|
|
})?,
|
|
)),
|
|
|
|
Expr::Or(lhs, rhs) => Ok(Box::new(
|
|
*self
|
|
.eval_expr(scope, &*lhs, level)?
|
|
.downcast::<bool>()
|
|
.map_err(|_| {
|
|
EvalAltResult::ErrorBooleanArgMismatch("OR".into(), lhs.position())
|
|
})?
|
|
|| // Short-circuit using ||
|
|
*self
|
|
.eval_expr(scope, &*rhs, level)?
|
|
.downcast::<bool>()
|
|
.map_err(|_| {
|
|
EvalAltResult::ErrorBooleanArgMismatch("OR".into(), rhs.position())
|
|
})?,
|
|
)),
|
|
|
|
Expr::True(_) => Ok(true.into_dynamic()),
|
|
Expr::False(_) => Ok(false.into_dynamic()),
|
|
Expr::Unit(_) => Ok(().into_dynamic()),
|
|
}
|
|
}
|
|
|
|
/// Evaluate a statement
|
|
pub(crate) fn eval_stmt(
|
|
&mut self,
|
|
scope: &mut Scope,
|
|
stmt: &Stmt,
|
|
level: usize,
|
|
) -> Result<Dynamic, EvalAltResult> {
|
|
match stmt {
|
|
// No-op
|
|
Stmt::Noop(_) => Ok(().into_dynamic()),
|
|
|
|
// Expression as statement
|
|
Stmt::Expr(expr) => {
|
|
let result = self.eval_expr(scope, expr, level)?;
|
|
|
|
Ok(if !matches!(expr.as_ref(), Expr::Assignment(_, _, _)) {
|
|
result
|
|
} else {
|
|
// If it is an assignment, erase the result at the root
|
|
().into_dynamic()
|
|
})
|
|
}
|
|
|
|
// Block scope
|
|
Stmt::Block(block, _) => {
|
|
let prev_len = scope.len();
|
|
|
|
let result = block.iter().try_fold(().into_dynamic(), |_, stmt| {
|
|
self.eval_stmt(scope, stmt, level)
|
|
});
|
|
|
|
scope.rewind(prev_len);
|
|
|
|
result
|
|
}
|
|
|
|
// If-else statement
|
|
Stmt::IfThenElse(guard, if_body, else_body) => self
|
|
.eval_expr(scope, guard, level)?
|
|
.downcast::<bool>()
|
|
.map_err(|_| EvalAltResult::ErrorLogicGuard(guard.position()))
|
|
.and_then(|guard_val| {
|
|
if *guard_val {
|
|
self.eval_stmt(scope, if_body, level)
|
|
} else if let Some(stmt) = else_body {
|
|
self.eval_stmt(scope, stmt.as_ref(), level)
|
|
} else {
|
|
Ok(().into_dynamic())
|
|
}
|
|
}),
|
|
|
|
// While loop
|
|
Stmt::While(guard, body) => loop {
|
|
match self.eval_expr(scope, guard, level)?.downcast::<bool>() {
|
|
Ok(guard_val) => {
|
|
if *guard_val {
|
|
match self.eval_stmt(scope, body, level) {
|
|
Ok(_) => (),
|
|
Err(EvalAltResult::ErrorLoopBreak(_)) => {
|
|
return Ok(().into_dynamic())
|
|
}
|
|
Err(x) => return Err(x),
|
|
}
|
|
} else {
|
|
return Ok(().into_dynamic());
|
|
}
|
|
}
|
|
Err(_) => return Err(EvalAltResult::ErrorLogicGuard(guard.position())),
|
|
}
|
|
},
|
|
|
|
// Loop statement
|
|
Stmt::Loop(body) => loop {
|
|
match self.eval_stmt(scope, body, level) {
|
|
Ok(_) => (),
|
|
Err(EvalAltResult::ErrorLoopBreak(_)) => return Ok(().into_dynamic()),
|
|
Err(x) => return Err(x),
|
|
}
|
|
},
|
|
|
|
// For loop
|
|
Stmt::For(name, expr, body) => {
|
|
let arr = self.eval_expr(scope, expr, level)?;
|
|
let tid = Any::type_id(&*arr);
|
|
|
|
if let Some(iter_fn) = self.type_iterators.get(&tid) {
|
|
scope.push(name.clone(), ());
|
|
|
|
let entry = ScopeSource {
|
|
name,
|
|
index: scope.len() - 1,
|
|
typ: ScopeEntryType::Normal,
|
|
};
|
|
|
|
for a in iter_fn(&arr) {
|
|
*scope.get_mut(entry) = a;
|
|
|
|
match self.eval_stmt(scope, body, level) {
|
|
Ok(_) => (),
|
|
Err(EvalAltResult::ErrorLoopBreak(_)) => break,
|
|
Err(x) => return Err(x),
|
|
}
|
|
}
|
|
|
|
scope.rewind(scope.len() - 1);
|
|
Ok(().into_dynamic())
|
|
} else {
|
|
Err(EvalAltResult::ErrorFor(expr.position()))
|
|
}
|
|
}
|
|
|
|
// Break statement
|
|
Stmt::Break(pos) => Err(EvalAltResult::ErrorLoopBreak(*pos)),
|
|
|
|
// Empty return
|
|
Stmt::ReturnWithVal(None, ReturnType::Return, pos) => {
|
|
Err(EvalAltResult::Return(().into_dynamic(), *pos))
|
|
}
|
|
|
|
// Return value
|
|
Stmt::ReturnWithVal(Some(a), ReturnType::Return, pos) => Err(EvalAltResult::Return(
|
|
self.eval_expr(scope, a, level)?,
|
|
*pos,
|
|
)),
|
|
|
|
// Empty throw
|
|
Stmt::ReturnWithVal(None, ReturnType::Exception, pos) => {
|
|
Err(EvalAltResult::ErrorRuntime("".into(), *pos))
|
|
}
|
|
|
|
// Throw value
|
|
Stmt::ReturnWithVal(Some(a), ReturnType::Exception, pos) => {
|
|
let val = self.eval_expr(scope, a, level)?;
|
|
Err(EvalAltResult::ErrorRuntime(
|
|
val.downcast::<String>()
|
|
.map(|s| *s)
|
|
.unwrap_or_else(|_| "".to_string()),
|
|
*pos,
|
|
))
|
|
}
|
|
|
|
// Let statement
|
|
Stmt::Let(name, Some(expr), _) => {
|
|
let val = self.eval_expr(scope, expr, level)?;
|
|
scope.push_dynamic_value(name.clone(), ScopeEntryType::Normal, val, false);
|
|
Ok(().into_dynamic())
|
|
}
|
|
|
|
Stmt::Let(name, None, _) => {
|
|
scope.push(name.clone(), ());
|
|
Ok(().into_dynamic())
|
|
}
|
|
|
|
// Const statement
|
|
Stmt::Const(name, expr, _) if expr.is_constant() => {
|
|
let val = self.eval_expr(scope, expr, level)?;
|
|
scope.push_dynamic_value(name.clone(), ScopeEntryType::Constant, val, true);
|
|
Ok(().into_dynamic())
|
|
}
|
|
|
|
Stmt::Const(_, _, _) => panic!("constant expression not constant!"),
|
|
}
|
|
}
|
|
|
|
/// Map a type_name into a pretty-print name
|
|
pub(crate) fn map_type_name<'a>(&'a self, name: &'a str) -> &'a str {
|
|
self.type_names
|
|
.get(name)
|
|
.map(String::as_str)
|
|
.unwrap_or(name)
|
|
}
|
|
|
|
/// Clean up all script-defined functions within the `Engine`.
|
|
pub fn clear_functions(&mut self) {
|
|
self.fn_lib.clear();
|
|
}
|
|
}
|
|
|
|
/// Print/debug to stdout
|
|
#[cfg(not(feature = "no_std"))]
|
|
#[cfg(not(feature = "no_stdlib"))]
|
|
fn default_print(s: &str) {
|
|
println!("{}", s);
|
|
}
|
|
|
|
/// No-op
|
|
#[cfg(any(feature = "no_std", feature = "no_stdlib"))]
|
|
fn default_print(_: &str) {}
|