1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
//! Configuration settings for [`Engine`].
use crate::stdlib::{format, num::NonZeroU8, string::String};
use crate::token::Token;
use crate::Engine;
#[cfg(not(feature = "unchecked"))]
use crate::stdlib::num::{NonZeroU64, NonZeroUsize};
#[cfg(not(feature = "no_module"))]
use crate::stdlib::boxed::Box;
impl Engine {
/// Control whether and how the [`Engine`] will optimize an [`AST`][crate::AST] after compilation.
///
/// Not available under `no_optimize`.
#[cfg(not(feature = "no_optimize"))]
#[inline(always)]
pub fn set_optimization_level(
&mut self,
optimization_level: crate::OptimizationLevel,
) -> &mut Self {
self.optimization_level = optimization_level;
self
}
/// The current optimization level.
/// It controls whether and how the [`Engine`] will optimize an [`AST`][crate::AST] after compilation.
///
/// Not available under `no_optimize`.
#[cfg(not(feature = "no_optimize"))]
#[inline(always)]
pub fn optimization_level(&self) -> crate::OptimizationLevel {
self.optimization_level
}
/// Enable/disable doc-comments.
#[inline(always)]
pub fn enable_doc_comments(&mut self, enable: bool) -> &mut Self {
self.disable_doc_comments = !enable;
self
}
/// Set the maximum levels of function calls allowed for a script in order to avoid
/// infinite recursion and stack overflows.
///
/// Not available under `unchecked` or `no_function`.
#[cfg(not(feature = "unchecked"))]
#[cfg(not(feature = "no_function"))]
#[inline(always)]
pub fn set_max_call_levels(&mut self, levels: usize) -> &mut Self {
self.limits.max_call_stack_depth = levels;
self
}
/// The maximum levels of function calls allowed for a script.
///
/// Not available under `unchecked` or `no_function`.
#[cfg(not(feature = "unchecked"))]
#[cfg(not(feature = "no_function"))]
#[inline(always)]
pub fn max_call_levels(&self) -> usize {
self.limits.max_call_stack_depth
}
/// Set the maximum number of operations allowed for a script to run to avoid
/// consuming too much resources (0 for unlimited).
///
/// Not available under `unchecked`.
#[cfg(not(feature = "unchecked"))]
#[inline(always)]
pub fn set_max_operations(&mut self, operations: u64) -> &mut Self {
self.limits.max_operations = NonZeroU64::new(operations);
self
}
/// The maximum number of operations allowed for a script to run (0 for unlimited).
///
/// Not available under `unchecked`.
#[cfg(not(feature = "unchecked"))]
#[inline(always)]
pub fn max_operations(&self) -> u64 {
self.limits.max_operations.map_or(0, NonZeroU64::get)
}
/// Set the maximum number of imported [modules][crate::Module] allowed for a script.
///
/// Not available under `unchecked` or `no_module`.
#[cfg(not(feature = "unchecked"))]
#[cfg(not(feature = "no_module"))]
#[inline(always)]
pub fn set_max_modules(&mut self, modules: usize) -> &mut Self {
self.limits.max_modules = modules;
self
}
/// The maximum number of imported [modules][crate::Module] allowed for a script.
///
/// Not available under `unchecked` or `no_module`.
#[cfg(not(feature = "unchecked"))]
#[cfg(not(feature = "no_module"))]
#[inline(always)]
pub fn max_modules(&self) -> usize {
self.limits.max_modules
}
/// Set the depth limits for expressions (0 for unlimited).
///
/// Not available under `unchecked`.
#[cfg(not(feature = "unchecked"))]
#[inline(always)]
pub fn set_max_expr_depths(
&mut self,
max_expr_depth: usize,
#[cfg(not(feature = "no_function"))] max_function_expr_depth: usize,
) -> &mut Self {
self.limits.max_expr_depth = NonZeroUsize::new(max_expr_depth);
#[cfg(not(feature = "no_function"))]
{
self.limits.max_function_expr_depth = NonZeroUsize::new(max_function_expr_depth);
}
self
}
/// The depth limit for expressions (0 for unlimited).
///
/// Not available under `unchecked`.
#[cfg(not(feature = "unchecked"))]
#[inline(always)]
pub fn max_expr_depth(&self) -> usize {
self.limits.max_expr_depth.map_or(0, NonZeroUsize::get)
}
/// The depth limit for expressions in functions (0 for unlimited).
///
/// Not available under `unchecked` or `no_function`.
#[cfg(not(feature = "unchecked"))]
#[cfg(not(feature = "no_function"))]
#[inline(always)]
pub fn max_function_expr_depth(&self) -> usize {
self.limits
.max_function_expr_depth
.map_or(0, NonZeroUsize::get)
}
/// Set the maximum length of [strings][crate::ImmutableString] (0 for unlimited).
///
/// Not available under `unchecked`.
#[cfg(not(feature = "unchecked"))]
#[inline(always)]
pub fn set_max_string_size(&mut self, max_size: usize) -> &mut Self {
self.limits.max_string_size = NonZeroUsize::new(max_size);
self
}
/// The maximum length of [strings][crate::ImmutableString] (0 for unlimited).
///
/// Not available under `unchecked`.
#[cfg(not(feature = "unchecked"))]
#[inline(always)]
pub fn max_string_size(&self) -> usize {
self.limits.max_string_size.map_or(0, NonZeroUsize::get)
}
/// Set the maximum length of [arrays][crate::Array] (0 for unlimited).
///
/// Not available under `unchecked` or `no_index`.
#[cfg(not(feature = "unchecked"))]
#[cfg(not(feature = "no_index"))]
#[inline(always)]
pub fn set_max_array_size(&mut self, max_size: usize) -> &mut Self {
self.limits.max_array_size = NonZeroUsize::new(max_size);
self
}
/// The maximum length of [arrays][crate::Array] (0 for unlimited).
///
/// Not available under `unchecked` or `no_index`.
#[cfg(not(feature = "unchecked"))]
#[cfg(not(feature = "no_index"))]
#[inline(always)]
pub fn max_array_size(&self) -> usize {
self.limits.max_array_size.map_or(0, NonZeroUsize::get)
}
/// Set the maximum size of [object maps][crate::Map] (0 for unlimited).
///
/// Not available under `unchecked` or `no_object`.
#[cfg(not(feature = "unchecked"))]
#[cfg(not(feature = "no_object"))]
#[inline(always)]
pub fn set_max_map_size(&mut self, max_size: usize) -> &mut Self {
self.limits.max_map_size = NonZeroUsize::new(max_size);
self
}
/// The maximum size of [object maps][crate::Map] (0 for unlimited).
///
/// Not available under `unchecked` or `no_object`.
#[cfg(not(feature = "unchecked"))]
#[cfg(not(feature = "no_object"))]
#[inline(always)]
pub fn max_map_size(&self) -> usize {
self.limits.max_map_size.map_or(0, NonZeroUsize::get)
}
/// Set the module resolution service used by the [`Engine`].
///
/// Not available under `no_module`.
#[cfg(not(feature = "no_module"))]
#[inline(always)]
pub fn set_module_resolver(
&mut self,
resolver: impl crate::ModuleResolver + 'static,
) -> &mut Self {
self.module_resolver = Box::new(resolver);
self
}
/// Disable a particular keyword or operator in the language.
///
/// # Examples
///
/// The following will raise an error during parsing because the `if` keyword is disabled
/// and is recognized as a variable name!
///
/// ```rust,should_panic
/// # fn main() -> Result<(), rhai::ParseError> {
/// use rhai::Engine;
///
/// let mut engine = Engine::new();
///
/// engine.disable_symbol("if"); // disable the 'if' keyword
///
/// engine.compile("let x = if true { 42 } else { 0 };")?;
/// // ^ 'if' is rejected as a reserved keyword
/// # Ok(())
/// # }
/// ```
///
/// The following will raise an error during parsing because the `+=` operator is disabled.
///
/// ```rust,should_panic
/// # fn main() -> Result<(), rhai::ParseError> {
/// use rhai::Engine;
///
/// let mut engine = Engine::new();
///
/// engine.disable_symbol("+="); // disable the '+=' operator
///
/// engine.compile("let x = 42; x += 1;")?;
/// // ^ unknown operator
/// # Ok(())
/// # }
/// ```
#[inline(always)]
pub fn disable_symbol(&mut self, symbol: &str) -> &mut Self {
self.disabled_symbols.insert(symbol.into());
self
}
/// Register a custom operator with a precedence into the language.
///
/// The operator must be a valid identifier (i.e. it cannot be a symbol).
///
/// The precedence cannot be zero.
///
/// # Example
///
/// ```rust
/// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
/// use rhai::{Engine, RegisterFn};
///
/// let mut engine = Engine::new();
///
/// // Register a custom operator called 'foo' and give it
/// // a precedence of 160 (i.e. between +|- and *|/).
/// engine.register_custom_operator("foo", 160).unwrap();
///
/// // Register a binary function named 'foo'
/// engine.register_fn("foo", |x: i64, y: i64| (x * y) - (x + y));
///
/// assert_eq!(
/// engine.eval_expression::<i64>("1 + 2 * 3 foo 4 - 5 / 6")?,
/// 15
/// );
/// # Ok(())
/// # }
/// ```
pub fn register_custom_operator(
&mut self,
keyword: &str,
precedence: u8,
) -> Result<&mut Self, String> {
let precedence = NonZeroU8::new(precedence);
if precedence.is_none() {
return Err("precedence cannot be zero".into());
}
match Token::lookup_from_syntax(keyword) {
// Standard identifiers, reserved keywords and custom keywords are OK
None | Some(Token::Reserved(_)) | Some(Token::Custom(_)) => (),
// Active standard keywords cannot be made custom
// Disabled keywords are OK
Some(token) if token.is_keyword() => {
if !self.disabled_symbols.contains(token.syntax().as_ref()) {
return Err(format!("'{}' is a reserved keyword", keyword).into());
}
}
// Active standard symbols cannot be made custom
Some(token) if token.is_symbol() => {
if !self.disabled_symbols.contains(token.syntax().as_ref()) {
return Err(format!("'{}' is a reserved operator", keyword).into());
}
}
// Active standard symbols cannot be made custom
Some(token) if !self.disabled_symbols.contains(token.syntax().as_ref()) => {
return Err(format!("'{}' is a reserved symbol", keyword).into())
}
// Disabled symbols are OK
Some(_) => (),
}
// Add to custom keywords
self.custom_keywords.insert(keyword.into(), precedence);
Ok(self)
}
}