Struct quad_compat_rhai::AST [−][src]
pub struct AST { /* fields omitted */ }
Expand description
Compiled AST (abstract syntax tree) of a Rhai script.
Thread Safety
Currently, AST
is neither Send
nor Sync
. Turn on the sync
feature to make it Send + Sync
.
Implementations
(internals) Create a new AST
.
Exported under the internals
feature only.
pub fn new_with_source(
statements: impl IntoIterator<Item = Stmt>,
functions: impl Into<Shared<Module>>,
source: impl Into<Identifier>
) -> Self
pub fn new_with_source(
statements: impl IntoIterator<Item = Stmt>,
functions: impl Into<Shared<Module>>,
source: impl Into<Identifier>
) -> Self
(internals) Create a new AST
with a source name.
Exported under the internals
feature only.
Set the source.
Clear the source.
(internals) Get the statements.
Exported under the internals
feature only.
Does this AST
contain script-defined functions?
Not available under no_function
.
(internals) Get the internal shared Module
containing all script-defined functions.
Exported under the internals
feature only.
Not available under no_function
.
(internals) Get the embedded module resolver.
Exported under the internals
feature only.
Not available under no_module
.
pub fn clone_functions_only_filtered(
&self,
filter: impl Fn(FnNamespace, FnAccess, bool, &str, usize) -> bool
) -> Self
pub fn clone_functions_only_filtered(
&self,
filter: impl Fn(FnNamespace, FnAccess, bool, &str, usize) -> bool
) -> Self
Merge two AST
into one. Both AST
’s are untouched and a new, merged,
version is returned.
Statements in the second AST
are simply appended to the end of the first without any processing.
Thus, the return value of the first AST
(if using expression-statement syntax) is buried.
Of course, if the first AST
uses a return
statement at the end, then
the second AST
will essentially be dead code.
All script-defined functions in the second AST
overwrite similarly-named functions
in the first AST
with the same number of parameters.
Example
use quad_compat_rhai::Engine;
let engine = Engine::new();
let ast1 = engine.compile("
fn foo(x) { 42 + x }
foo(1)
")?;
let ast2 = engine.compile(r#"
fn foo(n) { `hello${n}` }
foo("!")
"#)?;
let ast = ast1.merge(&ast2); // Merge 'ast2' into 'ast1'
// Notice that using the '+' operator also works:
// let ast = &ast1 + &ast2;
// 'ast' is essentially:
//
// fn foo(n) { `hello${n}` } // <- definition of first 'foo' is overwritten
// foo(1) // <- notice this will be "hello1" instead of 43,
// // but it is no longer the return value
// foo("!") // returns "hello!"
// Evaluate it
assert_eq!(engine.eval_ast::<String>(&ast)?, "hello!");
Combine one AST
with another. The second AST
is consumed.
Statements in the second AST
are simply appended to the end of the first without any processing.
Thus, the return value of the first AST
(if using expression-statement syntax) is buried.
Of course, if the first AST
uses a return
statement at the end, then
the second AST
will essentially be dead code.
All script-defined functions in the second AST
overwrite similarly-named functions
in the first AST
with the same number of parameters.
Example
use quad_compat_rhai::Engine;
let engine = Engine::new();
let mut ast1 = engine.compile("
fn foo(x) { 42 + x }
foo(1)
")?;
let ast2 = engine.compile(r#"
fn foo(n) { `hello${n}` }
foo("!")
"#)?;
ast1.combine(ast2); // Combine 'ast2' into 'ast1'
// Notice that using the '+=' operator also works:
// ast1 += ast2;
// 'ast1' is essentially:
//
// fn foo(n) { `hello${n}` } // <- definition of first 'foo' is overwritten
// foo(1) // <- notice this will be "hello1" instead of 43,
// // but it is no longer the return value
// foo("!") // returns "hello!"
// Evaluate it
assert_eq!(engine.eval_ast::<String>(&ast1)?, "hello!");
pub fn merge_filtered(
&self,
other: &Self,
filter: impl Fn(FnNamespace, FnAccess, bool, &str, usize) -> bool
) -> Self
pub fn merge_filtered(
&self,
other: &Self,
filter: impl Fn(FnNamespace, FnAccess, bool, &str, usize) -> bool
) -> Self
Merge two AST
into one. Both AST
’s are untouched and a new, merged, version
is returned.
Not available under no_function
.
Statements in the second AST
are simply appended to the end of the first without any processing.
Thus, the return value of the first AST
(if using expression-statement syntax) is buried.
Of course, if the first AST
uses a return
statement at the end, then
the second AST
will essentially be dead code.
All script-defined functions in the second AST
are first selected based on a filter
predicate, then overwrite similarly-named functions in the first AST
with the
same number of parameters.
Example
use quad_compat_rhai::Engine;
let engine = Engine::new();
let ast1 = engine.compile("
fn foo(x) { 42 + x }
foo(1)
")?;
let ast2 = engine.compile(r#"
fn foo(n) { `hello${n}` }
fn error() { 0 }
foo("!")
"#)?;
// Merge 'ast2', picking only 'error()' but not 'foo(_)', into 'ast1'
let ast = ast1.merge_filtered(&ast2, |_, _, script, name, params|
script && name == "error" && params == 0);
// 'ast' is essentially:
//
// fn foo(n) { 42 + n } // <- definition of 'ast1::foo' is not overwritten
// // because 'ast2::foo' is filtered away
// foo(1) // <- notice this will be 43 instead of "hello1",
// // but it is no longer the return value
// fn error() { 0 } // <- this function passes the filter and is merged
// foo("!") // <- returns "42!"
// Evaluate it
assert_eq!(engine.eval_ast::<String>(&ast)?, "42!");
pub fn combine_filtered(
&mut self,
other: Self,
filter: impl Fn(FnNamespace, FnAccess, bool, &str, usize) -> bool
) -> &mut Self
pub fn combine_filtered(
&mut self,
other: Self,
filter: impl Fn(FnNamespace, FnAccess, bool, &str, usize) -> bool
) -> &mut Self
Combine one AST
with another. The second AST
is consumed.
Not available under no_function
.
Statements in the second AST
are simply appended to the end of the first without any processing.
Thus, the return value of the first AST
(if using expression-statement syntax) is buried.
Of course, if the first AST
uses a return
statement at the end, then
the second AST
will essentially be dead code.
All script-defined functions in the second AST
are first selected based on a filter
predicate, then overwrite similarly-named functions in the first AST
with the
same number of parameters.
Example
use quad_compat_rhai::Engine;
let engine = Engine::new();
let mut ast1 = engine.compile("
fn foo(x) { 42 + x }
foo(1)
")?;
let ast2 = engine.compile(r#"
fn foo(n) { `hello${n}` }
fn error() { 0 }
foo("!")
"#)?;
// Combine 'ast2', picking only 'error()' but not 'foo(_)', into 'ast1'
ast1.combine_filtered(ast2, |_, _, script, name, params|
script && name == "error" && params == 0);
// 'ast1' is essentially:
//
// fn foo(n) { 42 + n } // <- definition of 'ast1::foo' is not overwritten
// // because 'ast2::foo' is filtered away
// foo(1) // <- notice this will be 43 instead of "hello1",
// // but it is no longer the return value
// fn error() { 0 } // <- this function passes the filter and is merged
// foo("!") // <- returns "42!"
// Evaluate it
assert_eq!(engine.eval_ast::<String>(&ast1)?, "42!");
pub fn retain_functions(
&mut self,
filter: impl Fn(FnNamespace, FnAccess, &str, usize) -> bool
) -> &mut Self
pub fn retain_functions(
&mut self,
filter: impl Fn(FnNamespace, FnAccess, &str, usize) -> bool
) -> &mut Self
Filter out the functions, retaining only some based on a filter predicate.
Not available under no_function
.
Example
use quad_compat_rhai::Engine;
let engine = Engine::new();
let mut ast = engine.compile(r#"
fn foo(n) { n + 1 }
fn bar() { print("hello"); }
"#)?;
// Remove all functions except 'foo(_)'
ast.retain_functions(|_, _, name, params| name == "foo" && params == 1);
Iterate through all function definitions.
Not available under no_function
.
Clear all function definitions in the AST
.
Not available under no_function
.
Clear all statements in the AST
, leaving only function definitions.
Extract all top-level literal constant and/or variable definitions. This is useful for extracting all global constants from a script without actually running it.
A literal constant/variable definition takes the form of:
const VAR =
value;
and let VAR =
value;
where value is a literal expression or will be optimized into a literal.
Example
use quad_compat_rhai::{Engine, Scope};
let engine = Engine::new();
let ast = engine.compile(
"
const A = 40 + 2; // constant that optimizes into a literal
let b = 123; // literal variable
const B = b * A; // non-literal constant
const C = 999; // literal constant
b = A + C; // expression
{ // <- new block scope
const Z = 0; // <- literal constant not at top-level
}
")?;
let mut iter = ast.iter_literal_variables(true, false)
.map(|(name, is_const, value)| (name, is_const, value.as_int().unwrap()));
assert_eq!(iter.next(), Some(("A", true, 42)));
assert_eq!(iter.next(), Some(("C", true, 999)));
assert_eq!(iter.next(), None);
let mut iter = ast.iter_literal_variables(false, true)
.map(|(name, is_const, value)| (name, is_const, value.as_int().unwrap()));
assert_eq!(iter.next(), Some(("b", false, 123)));
assert_eq!(iter.next(), None);
let mut iter = ast.iter_literal_variables(true, true)
.map(|(name, is_const, value)| (name, is_const, value.as_int().unwrap()));
assert_eq!(iter.next(), Some(("A", true, 42)));
assert_eq!(iter.next(), Some(("b", false, 123)));
assert_eq!(iter.next(), Some(("C", true, 999)));
assert_eq!(iter.next(), None);
let scope: Scope = ast.iter_literal_variables(true, false).collect();
assert_eq!(scope.len(), 2);
Ok(())
👎 Deprecated since 1.3.0: use shared_lib
instead
use shared_lib
instead
(internals) Get the internal Module
containing all script-defined functions.
Exported under the internals
feature only.
Not available under no_function
.
Deprecated
This method is deprecated. Use shared_lib
instead.
This method will be removed in the next major version.
Trait Implementations
Auto Trait Implementations
impl !RefUnwindSafe for AST
impl !UnwindSafe for AST
Blanket Implementations
Mutably borrows from an owned value. Read more