kjuulh/rhai
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Reduce cloning.

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This commit is contained in:
Stephen Chung
2020-03-11 23:43:04 +08:00
parent dbfc38763a
commit 952932f64c
3 changed files with 200 additions and 198 deletions
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236
src/engine.rs
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@@ -1,7 +1,7 @@
//! Main module defining the script evaluation `Engine`.
use crate::any::{Any, AnyExt, Dynamic, Variant};
use crate::parser::{Expr, FnDef, Position, Stmt};
use crate::parser::{Expr, FnDef, Position, ReturnType, Stmt};
use crate::result::EvalAltResult;
use crate::scope::Scope;
@@ -11,7 +11,6 @@ use crate::INT;
use std::{
any::{type_name, TypeId},
borrow::Cow,
cmp::{PartialEq, PartialOrd},
collections::HashMap,
iter::once,
sync::Arc,
@@ -34,7 +33,7 @@ pub(crate) const KEYWORD_TYPE_OF: &'static str = "type_of";
pub(crate) const FUNC_GETTER: &'static str = "get$";
pub(crate) const FUNC_SETTER: &'static str = "set$";
#[derive(Copy, Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
#[derive(Debug, Eq, PartialEq, Hash, Clone, Copy)]
#[cfg(not(feature = "no_index"))]
enum IndexSourceType {
Array,
@@ -42,7 +41,7 @@ enum IndexSourceType {
Expression,
}
#[derive(Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
#[derive(Debug, Eq, PartialEq, Hash)]
pub struct FnSpec<'a> {
pub name: Cow<'a, str>,
pub args: Option<Vec<TypeId>>,
@@ -66,11 +65,11 @@ pub struct Engine<'e> {
/// Optimize the AST after compilation
pub(crate) optimize: bool,
/// A hashmap containing all compiled functions known to the engine
pub(crate) ext_functions: HashMap<FnSpec<'e>, Arc<FnIntExt<'e>>>,
pub(crate) ext_functions: HashMap<FnSpec<'e>, Box<FnAny>>,
/// A hashmap containing all script-defined functions
pub(crate) script_functions: HashMap<FnSpec<'e>, Arc<FnIntExt<'e>>>,
pub(crate) script_functions: Vec<Arc<FnDef>>,
/// A hashmap containing all iterators known to the engine
pub(crate) type_iterators: HashMap<TypeId, Arc<IteratorFn>>,
pub(crate) type_iterators: HashMap<TypeId, Box<IteratorFn>>,
pub(crate) type_names: HashMap<String, String>,
// Closures for implementing the print/debug commands
@@ -78,11 +77,6 @@ pub struct Engine<'e> {
pub(crate) on_debug: Box<dyn FnMut(&str) + 'e>,
}
pub enum FnIntExt<'a> {
Ext(Box<FnAny>),
Int(FnDef<'a>),
}
impl Engine<'_> {
/// Create a new `Engine`
pub fn new() -> Self {
@@ -101,7 +95,7 @@ impl Engine<'_> {
let mut engine = Engine {
optimize: true,
ext_functions: HashMap::new(),
script_functions: HashMap::new(),
script_functions: Vec::new(),
type_iterators: HashMap::new(),
type_names,
on_print: Box::new(default_print), // default print/debug implementations
@@ -140,113 +134,112 @@ impl Engine<'_> {
.join(", ")
);
let mut spec = FnSpec {
// First search in script-defined functions (can override built-in)
if let Some(func) = self
.script_functions
.iter()
.rev()
.find(|fn_def| fn_def.name == fn_name)
.map(|fn_def| fn_def.clone())
{
// First check number of parameters
if func.params.len() != args.len() {
return Err(EvalAltResult::ErrorFunctionArgsMismatch(
fn_name.into(),
func.params.len(),
args.len(),
pos,
));
}
let mut scope = Scope::new();
scope.extend(
// Put arguments into scope as variables
func.params
.iter()
.zip(args.iter().map(|x| (*x).into_dynamic())),
);
// Evaluate
return match self.eval_stmt(&mut scope, &func.body) {
// Convert return statement to return value
Err(EvalAltResult::Return(x, _)) => Ok(x),
other => other,
};
}
let spec = FnSpec {
name: fn_name.into(),
args: None,
args: Some(args.iter().map(|a| Any::type_id(&**a)).collect()),
};
// First search in script-defined functions (can override built-in),
// then built-in's and external functions
let fn_def = self
.script_functions
.get(&spec)
.or_else(|| {
spec.args = Some(args.iter().map(|a| Any::type_id(&**a)).collect());
self.ext_functions.get(&spec)
})
.map(|f| f.clone());
// Then search built-in's and external functions
if let Some(func) = self.ext_functions.get(&spec) {
// Run external function
let result = func(args, pos)?;
if let Some(f) = fn_def {
match *f {
// Run external function
FnIntExt::Ext(ref func) => {
let result = func(args, pos)?;
// See if the function match print/debug (which requires special processing)
let callback = match spec.name.as_ref() {
KEYWORD_PRINT => self.on_print.as_mut(),
KEYWORD_DEBUG => self.on_debug.as_mut(),
_ => return Ok(result),
};
// See if the function match print/debug (which requires special processing)
let callback = match spec.name.as_ref() {
KEYWORD_PRINT => self.on_print.as_mut(),
KEYWORD_DEBUG => self.on_debug.as_mut(),
_ => return Ok(result),
};
let val = &result
.downcast::<String>()
.map(|s| *s)
.unwrap_or("error: not a string".into());
let val = &result
.downcast::<String>()
.map(|s| *s)
.unwrap_or("error: not a string".into());
return Ok(callback(val).into_dynamic());
}
Ok(callback(val).into_dynamic())
}
// Run script-defined function
FnIntExt::Int(ref func) => {
// First check number of parameters
if func.params.len() != args.len() {
return Err(EvalAltResult::ErrorFunctionArgsMismatch(
spec.name.into(),
func.params.len(),
args.len(),
pos,
));
}
let mut scope = Scope::new();
scope.extend(
// Put arguments into scope as variables
func.params
.iter()
.cloned()
.zip(args.iter().map(|x| (*x).into_dynamic())),
);
// Evaluate
match self.eval_stmt(&mut scope, &func.body) {
// Convert return statement to return value
Err(EvalAltResult::Return(x, _)) => Ok(x),
other => other,
}
}
}
} else if spec.name == KEYWORD_TYPE_OF && args.len() == 1 {
if spec.name == KEYWORD_TYPE_OF && args.len() == 1 {
// Handle `type_of` function
Ok(self
return Ok(self
.map_type_name(args[0].type_name())
.to_string()
.into_dynamic())
} else if spec.name.starts_with(FUNC_GETTER) {
.into_dynamic());
}
if spec.name.starts_with(FUNC_GETTER) {
// Getter function not found
Err(EvalAltResult::ErrorDotExpr(
return Err(EvalAltResult::ErrorDotExpr(
format!(
"- property '{}' unknown or write-only",
&spec.name[FUNC_GETTER.len()..]
),
pos,
))
} else if spec.name.starts_with(FUNC_SETTER) {
));
}
if spec.name.starts_with(FUNC_SETTER) {
// Setter function not found
Err(EvalAltResult::ErrorDotExpr(
return Err(EvalAltResult::ErrorDotExpr(
format!(
"- property '{}' unknown or read-only",
&spec.name[FUNC_SETTER.len()..]
),
pos,
))
} else if let Some(val) = def_val {
// Return default value
Ok(val.clone())
} else {
// Raise error
let types_list = args
.iter()
.map(|x| (*x).type_name())
.map(|name| self.map_type_name(name))
.collect::<Vec<_>>();
Err(EvalAltResult::ErrorFunctionNotFound(
format!("{} ({})", spec.name, types_list.join(", ")),
pos,
))
));
}
if let Some(val) = def_val {
// Return default value
return Ok(val.clone());
}
// Raise error
let types_list = args
.iter()
.map(|x| (*x).type_name())
.map(|name| self.map_type_name(name))
.collect::<Vec<_>>();
Err(EvalAltResult::ErrorFunctionNotFound(
format!("{} ({})", spec.name, types_list.join(", ")),
pos,
))
}
/// Chain-evaluate a dot setter
@@ -281,7 +274,7 @@ impl Engine<'_> {
// xxx.idx_lhs[idx_expr]
#[cfg(not(feature = "no_index"))]
Expr::Index(idx_lhs, idx_expr, idx_pos) => {
let (expr, _) = match idx_lhs.as_ref() {
let (val, _) = match idx_lhs.as_ref() {
// xxx.id[idx_expr]
Expr::Identifier(id, pos) => {
let get_fn_name = format!("{}{}", FUNC_GETTER, id);
@@ -304,7 +297,7 @@ impl Engine<'_> {
};
let idx = self.eval_index_value(scope, idx_expr)?;
self.get_indexed_value(expr, idx, idx_expr.position(), *idx_pos)
self.get_indexed_value(&val, idx, idx_expr.position(), *idx_pos)
.map(|(v, _)| v)
}
@@ -320,7 +313,7 @@ impl Engine<'_> {
// xxx.idx_lhs[idx_expr].rhs
#[cfg(not(feature = "no_index"))]
Expr::Index(idx_lhs, idx_expr, idx_pos) => {
let (expr, _) = match idx_lhs.as_ref() {
let (val, _) = match idx_lhs.as_ref() {
// xxx.id[idx_expr].rhs
Expr::Identifier(id, pos) => {
let get_fn_name = format!("{}{}", FUNC_GETTER, id);
@@ -343,7 +336,7 @@ impl Engine<'_> {
};
let idx = self.eval_index_value(scope, idx_expr)?;
self.get_indexed_value(expr, idx, idx_expr.position(), *idx_pos)
self.get_indexed_value(&val, idx, idx_expr.position(), *idx_pos)
.and_then(|(mut v, _)| self.get_dot_val_helper(scope, v.as_mut(), rhs))
}
// Syntax error
@@ -441,14 +434,14 @@ impl Engine<'_> {
#[cfg(not(feature = "no_index"))]
fn get_indexed_value(
&self,
val: Dynamic,
val: &Dynamic,
idx: INT,
val_pos: Position,
idx_pos: Position,
) -> Result<(Dynamic, IndexSourceType), EvalAltResult> {
if val.is::<Array>() {
// val_array[idx]
let arr = val.downcast::<Array>().expect("array expected");
let arr = val.downcast_ref::<Array>().expect("array expected");
if idx >= 0 {
arr.get(idx as usize)
@@ -460,7 +453,7 @@ impl Engine<'_> {
}
} else if val.is::<String>() {
// val_string[idx]
let s = val.downcast::<String>().expect("string expected");
let s = val.downcast_ref::<String>().expect("string expected");
if idx >= 0 {
s.chars()
@@ -501,7 +494,7 @@ impl Engine<'_> {
Expr::Identifier(id, _) => Self::search_scope(
scope,
&id,
|val| self.get_indexed_value(val, idx, idx_expr.position(), idx_pos),
|val| self.get_indexed_value(&val, idx, idx_expr.position(), idx_pos),
lhs.position(),
)
.map(|(src_idx, (val, src_type))| {
@@ -512,7 +505,7 @@ impl Engine<'_> {
expr => {
let val = self.eval_expr(scope, expr)?;
self.get_indexed_value(val, idx, idx_expr.position(), idx_pos)
self.get_indexed_value(&val, idx, idx_expr.position(), idx_pos)
.map(|(v, _)| (IndexSourceType::Expression, None, idx as usize, v))
}
}
@@ -663,12 +656,8 @@ impl Engine<'_> {
self.call_fn_raw(&get_fn_name, vec![this_ptr], None, *pos)
.and_then(|v| {
let idx = self.eval_index_value(scope, idx_expr)?;
let (mut target, _) = self.get_indexed_value(
v.clone(), // TODO - Avoid cloning this
idx,
idx_expr.position(),
*idx_pos,
)?;
let (mut target, _) =
self.get_indexed_value(&v, idx, idx_expr.position(), *idx_pos)?;
self.set_dot_val_helper(
scope,
@@ -1042,22 +1031,22 @@ impl Engine<'_> {
Stmt::Break(_) => Err(EvalAltResult::LoopBreak),
// Empty return
Stmt::ReturnWithVal(None, true, pos) => {
Stmt::ReturnWithVal(None, ReturnType::Return, pos) => {
Err(EvalAltResult::Return(().into_dynamic(), *pos))
}
// Return value
Stmt::ReturnWithVal(Some(a), true, pos) => {
Stmt::ReturnWithVal(Some(a), ReturnType::Return, pos) => {
Err(EvalAltResult::Return(self.eval_expr(scope, a)?, *pos))
}
// Empty throw
Stmt::ReturnWithVal(None, false, pos) => {
Stmt::ReturnWithVal(None, ReturnType::Exception, pos) => {
Err(EvalAltResult::ErrorRuntime("".into(), *pos))
}
// Throw value
Stmt::ReturnWithVal(Some(a), false, pos) => {
Stmt::ReturnWithVal(Some(a), ReturnType::Exception, pos) => {
let val = self.eval_expr(scope, a)?;
Err(EvalAltResult::ErrorRuntime(
val.downcast::<String>()
@@ -1068,13 +1057,14 @@ impl Engine<'_> {
}
// Let statement
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(), ());
}
Stmt::Let(name, Some(expr), _) => {
let val = self.eval_expr(scope, expr)?;
scope.push_dynamic(name.clone(), val);
Ok(().into_dynamic())
}
Stmt::Let(name, None, _) => {
scope.push(name.clone(), ());
Ok(().into_dynamic())
}
}