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Implement closures.

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This commit is contained in:
Stephen Chung
2020-08-03 12:10:20 +08:00
parent 747c0345f2
commit 4079164bfd
24 changed files with 340 additions and 588 deletions
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92
src/parser.rs
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@@ -39,7 +39,7 @@ use crate::stdlib::{
#[cfg(not(feature = "no_function"))]
use crate::stdlib::collections::hash_map::DefaultHasher;
#[cfg(not(feature = "no_capture"))]
#[cfg(not(feature = "no_closure"))]
use crate::stdlib::collections::HashSet;
#[cfg(feature = "no_std")]
@@ -366,7 +366,7 @@ pub struct ScriptFnDef {
/// Names of function parameters.
pub params: StaticVec<String>,
/// Access to external variables.
#[cfg(not(feature = "no_capture"))]
#[cfg(not(feature = "no_closure"))]
pub externals: HashSet<String>,
/// Function body.
pub body: Stmt,
@@ -414,13 +414,13 @@ struct ParseState<'e> {
/// Encapsulates a local stack with variable names to simulate an actual runtime scope.
stack: Vec<(String, ScopeEntryType)>,
/// Tracks a list of external variables (variables that are not explicitly declared in the scope).
#[cfg(not(feature = "no_capture"))]
#[cfg(not(feature = "no_closure"))]
externals: HashMap<String, Position>,
/// An indicator that prevents variables capturing into externals one time.
/// If set to true the next call of `access_var` will not capture the variable.
/// An indicator that disables variable capturing into externals one single time.
/// If set to false the next call to `access_var` will not capture the variable.
/// All consequent calls to `access_var` will not be affected
#[cfg(not(feature = "no_capture"))]
capture: bool,
#[cfg(not(feature = "no_closure"))]
allow_capture: bool,
/// Encapsulates a local stack with variable names to simulate an actual runtime scope.
modules: Vec<String>,
/// Maximum levels of expression nesting.
@@ -444,10 +444,10 @@ impl<'e> ParseState<'e> {
max_expr_depth,
#[cfg(not(feature = "unchecked"))]
max_function_expr_depth,
#[cfg(not(feature = "no_capture"))]
#[cfg(not(feature = "no_closure"))]
externals: Default::default(),
#[cfg(not(feature = "no_capture"))]
capture: true,
#[cfg(not(feature = "no_closure"))]
allow_capture: true,
stack: Default::default(),
modules: Default::default(),
}
@@ -469,13 +469,13 @@ impl<'e> ParseState<'e> {
.find(|(_, (n, _))| *n == name)
.and_then(|(i, _)| NonZeroUsize::new(i + 1));
#[cfg(not(feature = "no_capture"))]
if self.capture {
#[cfg(not(feature = "no_closure"))]
if self.allow_capture {
if index.is_none() && !self.externals.contains_key(name) {
self.externals.insert(name.to_string(), _pos);
}
} else {
self.capture = true
self.allow_capture = true
}
index
@@ -579,6 +579,9 @@ pub enum Stmt {
Position,
)>,
),
/// Convert a variable to shared.
#[cfg(not(feature = "no_closure"))]
Share(Box<(String, Position)>),
}
impl Default for Stmt {
@@ -606,6 +609,9 @@ impl Stmt {
Stmt::Import(x) => x.2,
#[cfg(not(feature = "no_module"))]
Stmt::Export(x) => x.1,
#[cfg(not(feature = "no_closure"))]
Stmt::Share(x) => x.1,
}
}
@@ -629,6 +635,9 @@ impl Stmt {
Stmt::Import(x) => x.2 = new_pos,
#[cfg(not(feature = "no_module"))]
Stmt::Export(x) => x.1 = new_pos,
#[cfg(not(feature = "no_closure"))]
Stmt::Share(x) => x.1 = new_pos,
}
self
@@ -655,6 +664,9 @@ impl Stmt {
#[cfg(not(feature = "no_module"))]
Stmt::Import(_) | Stmt::Export(_) => false,
#[cfg(not(feature = "no_closure"))]
Stmt::Share(_) => false,
}
}
@@ -678,6 +690,9 @@ impl Stmt {
Stmt::Import(_) => false,
#[cfg(not(feature = "no_module"))]
Stmt::Export(_) => false,
#[cfg(not(feature = "no_closure"))]
Stmt::Share(_) => false,
}
}
}
@@ -1671,7 +1686,7 @@ fn parse_primary(
root_expr = match (root_expr, token) {
// Function call
#[cfg(not(feature = "no_capture"))]
#[cfg(not(feature = "no_closure"))]
(Expr::Variable(x), Token::Bang) => {
if !match_token(input, Token::LeftParen)? {
return Err(PERR::MissingToken(
@@ -1855,7 +1870,7 @@ fn parse_unary(
let (expr, func) = parse_anon_fn(input, &mut new_state, lib, settings)?;
#[cfg(not(feature = "no_capture"))]
#[cfg(not(feature = "no_closure"))]
new_state.externals.iter().for_each(|(closure, pos)| {
state.access_var(closure, *pos);
});
@@ -2216,9 +2231,9 @@ fn parse_binary_op(
if cfg!(not(feature = "no_object")) && op_token == Token::Period {
if let (Token::Identifier(_), _) = input.peek().unwrap() {
// prevents capturing of the object properties as vars: xxx.<var>
#[cfg(not(feature = "no_capture"))]
#[cfg(not(feature = "no_closure"))]
{
state.capture = false;
state.allow_capture = false;
}
}
}
@@ -3095,7 +3110,7 @@ fn parse_fn(
let params: StaticVec<_> = params.into_iter().map(|(p, _)| p).collect();
#[cfg(not(feature = "no_capture"))]
#[cfg(not(feature = "no_closure"))]
let externals = state
.externals
.iter()
@@ -3108,7 +3123,7 @@ fn parse_fn(
name: name.into(),
access,
params,
#[cfg(not(feature = "no_capture"))]
#[cfg(not(feature = "no_closure"))]
externals,
body,
pos: settings.pos,
@@ -3128,6 +3143,17 @@ fn make_curry_from_externals(
let num_externals = externals.len();
let mut args: StaticVec<_> = Default::default();
#[cfg(not(feature = "no_closure"))]
externals.iter().for_each(|(var_name, pos)| {
args.push(Expr::Variable(Box::new((
(var_name.into(), *pos),
None,
0,
None,
))));
});
#[cfg(feature = "no_closure")]
externals.into_iter().for_each(|(var_name, pos)| {
args.push(Expr::Variable(Box::new(((var_name, pos), None, 0, None))));
});
@@ -3142,7 +3168,23 @@ fn make_curry_from_externals(
None,
)));
Expr::Dot(Box::new((fn_expr, fn_call, pos)))
let expr = Expr::Dot(Box::new((fn_expr, fn_call, pos)));
// If there are captured variables, convert the entire expression into a statement block,
// then insert the relevant `Share` statements.
#[cfg(not(feature = "no_closure"))]
{
// Statement block
let mut statements: StaticVec<_> = Default::default();
// Insert `Share` statements
statements.extend(externals.into_iter().map(|x| Stmt::Share(Box::new(x))));
// Final expression
statements.push(Stmt::Expr(Box::new(expr)));
Expr::Stmt(Box::new((Stmt::Block(Box::new((statements, pos))), pos)))
}
#[cfg(feature = "no_closure")]
return expr;
}
/// Parse an anonymous function definition.
@@ -3215,7 +3257,7 @@ fn parse_anon_fn(
// External variables may need to be processed in a consistent order,
// so extract them into a list.
let externals: StaticVec<_> = {
#[cfg(not(feature = "no_capture"))]
#[cfg(not(feature = "no_closure"))]
{
state
.externals
@@ -3223,11 +3265,11 @@ fn parse_anon_fn(
.map(|(k, &v)| (k.clone(), v))
.collect()
}
#[cfg(feature = "no_capture")]
#[cfg(feature = "no_closure")]
Default::default()
};
let params: StaticVec<_> = if cfg!(not(feature = "no_capture")) {
let params: StaticVec<_> = if cfg!(not(feature = "no_closure")) {
externals
.iter()
.map(|(k, _)| k)
@@ -3257,7 +3299,7 @@ fn parse_anon_fn(
name: fn_name.clone(),
access: FnAccess::Public,
params,
#[cfg(not(feature = "no_capture"))]
#[cfg(not(feature = "no_closure"))]
externals: Default::default(),
body,
pos: settings.pos,
@@ -3265,7 +3307,7 @@ fn parse_anon_fn(
let expr = Expr::FnPointer(Box::new((fn_name, settings.pos)));
let expr = if cfg!(not(feature = "no_capture")) {
let expr = if cfg!(not(feature = "no_closure")) {
make_curry_from_externals(expr, externals, settings.pos)
} else {
expr