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Implement bit-fields.

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This commit is contained in:
Stephen Chung 2021-06-02 14:29:18 +08:00
parent 25e99af07e
commit 71684f5e2a
11 changed files with 497 additions and 97 deletions
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10
CHANGELOG.md
View File

@ -4,6 +4,16 @@ Rhai Release Notes
Version 0.20.3
==============
Bug fixes
---------
* Fixed incorrect optimization regarding chain-indexing with non-numeric index.
New features
------------
* An integer value can now be indexed to get/set a single bit.
Version 0.20.2
==============

4
src/ast.rs
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@ -2014,13 +2014,13 @@ impl Expr {
Self::DynamicConstant(_, _)
| Self::BoolConstant(_, _)
| Self::IntegerConstant(_, _)
| Self::CharConstant(_, _)
| Self::And(_, _)
| Self::Or(_, _)
| Self::Unit(_) => false,
Self::StringConstant(_, _)
Self::IntegerConstant(_, _)
| Self::StringConstant(_, _)
| Self::InterpolatedString(_)
| Self::FnCall(_, _)
| Self::Stmt(_)

2
src/bin/rhai-run.rs
View File

@ -83,7 +83,7 @@ fn main() {
if let Err(err) = engine
.compile(contents)
.map_err(|err| Box::new(err.into()) as Box<EvalAltResult>)
.map_err(|err| err.into())
.and_then(|mut ast| {
ast.set_source(filename.to_string_lossy().to_string());
engine.consume_ast(&ast)

171
src/engine.rs
View File

@ -336,6 +336,10 @@ pub enum Target<'a> {
LockGuard((crate::dynamic::DynamicWriteLock<'a, Dynamic>, Dynamic)),
/// The target is a temporary `Dynamic` value (i.e. the mutation can cause no side effects).
Value(Dynamic),
/// The target is a bit inside an [`INT`][crate::INT].
/// This is necessary because directly pointing to a bit inside an [`INT`][crate::INT] is impossible.
#[cfg(not(feature = "no_index"))]
BitField(&'a mut Dynamic, usize, Dynamic),
/// The target is a character inside a String.
/// This is necessary because directly pointing to a char inside a String is impossible.
#[cfg(not(feature = "no_index"))]
@ -354,6 +358,8 @@ impl<'a> Target<'a> {
Self::LockGuard(_) => true,
Self::Value(_) => false,
#[cfg(not(feature = "no_index"))]
Self::BitField(_, _, _) => false,
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, _) => false,
}
}
@ -368,6 +374,8 @@ impl<'a> Target<'a> {
Self::LockGuard(_) => false,
Self::Value(_) => true,
#[cfg(not(feature = "no_index"))]
Self::BitField(_, _, _) => false,
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, _) => false,
}
}
@ -382,6 +390,8 @@ impl<'a> Target<'a> {
Self::LockGuard(_) => true,
Self::Value(r) => r.is_shared(),
#[cfg(not(feature = "no_index"))]
Self::BitField(_, _, _) => false,
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, _) => false,
}
}
@ -396,6 +406,8 @@ impl<'a> Target<'a> {
Self::LockGuard((r, _)) => r.is::<T>(),
Self::Value(r) => r.is::<T>(),
#[cfg(not(feature = "no_index"))]
Self::BitField(_, _, _) => TypeId::of::<T>() == TypeId::of::<bool>(),
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, _) => TypeId::of::<T>() == TypeId::of::<char>(),
}
}
@ -409,6 +421,8 @@ impl<'a> Target<'a> {
Self::LockGuard((_, orig)) => orig, // Original value is simply taken
Self::Value(v) => v, // Owned value is simply taken
#[cfg(not(feature = "no_index"))]
Self::BitField(_, _, value) => value, // Boolean is taken
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, ch) => ch, // Character is taken
}
}
@ -435,9 +449,14 @@ impl<'a> Target<'a> {
#[cfg(not(feature = "no_closure"))]
Self::LockGuard(_) => Ok(()),
#[cfg(not(feature = "no_index"))]
Self::BitField(_, _, value) => {
let new_val = value.clone();
self.set_value(new_val, Position::NONE)
}
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, ch) => {
let char_value = ch.clone();
self.set_value(char_value, Position::NONE)
let new_val = ch.clone();
self.set_value(new_val, Position::NONE)
}
}
}
@ -454,6 +473,32 @@ impl<'a> Target<'a> {
Self::LockGuard((r, _)) => **r = new_val,
Self::Value(_) => panic!("cannot update a value"),
#[cfg(not(feature = "no_index"))]
Self::BitField(value, index, _) => {
let value = &mut *value
.write_lock::<crate::INT>()
.expect("never fails because `BitField` always holds an `INT`");
// Replace the bit at the specified index position
let new_bit = new_val.as_bool().map_err(|err| {
Box::new(EvalAltResult::ErrorMismatchDataType(
"bool".to_string(),
err.to_string(),
_pos,
))
})?;
let index = *index;
if index < std::mem::size_of_val(value) * 8 {
let mask = 1 << index;
if new_bit {
*value |= mask;
} else {
*value &= !mask;
}
}
}
#[cfg(not(feature = "no_index"))]
Self::StringChar(s, index, _) => {
let s = &mut *s
.write_lock::<ImmutableString>()
@ -514,6 +559,8 @@ impl Deref for Target<'_> {
Self::LockGuard((r, _)) => &**r,
Self::Value(ref r) => r,
#[cfg(not(feature = "no_index"))]
Self::BitField(_, _, ref r) => r,
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, ref r) => r,
}
}
@ -536,6 +583,8 @@ impl DerefMut for Target<'_> {
Self::LockGuard((r, _)) => r.deref_mut(),
Self::Value(ref mut r) => r,
#[cfg(not(feature = "no_index"))]
Self::BitField(_, _, ref mut r) => r,
#[cfg(not(feature = "no_index"))]
Self::StringChar(_, _, ref mut r) => r,
}
}
@ -1818,6 +1867,43 @@ impl Engine {
.unwrap_or_else(|| Target::from(Dynamic::UNIT)))
}
#[cfg(not(feature = "no_index"))]
Dynamic(Union::Int(value, _, _)) => {
// val_int[idx]
let index = idx
.as_int()
.map_err(|err| self.make_type_mismatch_err::<crate::INT>(err, idx_pos))?;
let bits = std::mem::size_of_val(value) * 8;
let (bit_value, offset) = if index >= 0 {
let offset = index as usize;
(
if offset >= bits {
return EvalAltResult::ErrorBitFieldBounds(bits, index, idx_pos).into();
} else {
(*value & (1 << offset)) != 0
},
offset,
)
} else if let Some(abs_index) = index.checked_abs() {
let offset = abs_index as usize;
(
// Count from end if negative
if offset > bits {
return EvalAltResult::ErrorBitFieldBounds(bits, index, idx_pos).into();
} else {
(*value & (1 << (bits - offset))) != 0
},
offset,
)
} else {
return EvalAltResult::ErrorBitFieldBounds(bits, index, idx_pos).into();
};
Ok(Target::BitField(target, offset, bit_value.into()))
}
#[cfg(not(feature = "no_index"))]
Dynamic(Union::Str(s, _, _)) => {
// val_string[idx]
@ -1826,7 +1912,6 @@ impl Engine {
.map_err(|err| self.make_type_mismatch_err::<crate::INT>(err, idx_pos))?;
let (ch, offset) = if index >= 0 {
// Count from end if negative
let offset = index as usize;
(
s.chars().nth(offset).ok_or_else(|| {
@ -1835,9 +1920,10 @@ impl Engine {
})?,
offset,
)
} else if let Some(index) = index.checked_abs() {
let offset = index as usize;
} else if let Some(abs_index) = index.checked_abs() {
let offset = abs_index as usize;
(
// Count from end if negative
s.chars().rev().nth(offset - 1).ok_or_else(|| {
let chars_len = s.chars().count();
EvalAltResult::ErrorStringBounds(chars_len, index, idx_pos)
@ -2153,8 +2239,8 @@ impl Engine {
op_pos: Position,
mut target: Target,
root: (&str, Position),
mut new_value: Dynamic,
new_value_pos: Position,
mut new_val: Dynamic,
new_val_pos: Position,
) -> Result<(), Box<EvalAltResult>> {
if target.is_read_only() {
// Assignment to constant variable
@ -2167,48 +2253,51 @@ impl Engine {
op,
}) = op_info
{
let mut lock_guard;
let lhs_ptr_inner;
{
let mut lock_guard;
let lhs_ptr_inner;
#[cfg(not(feature = "no_closure"))]
let target_is_shared = target.is_shared();
#[cfg(feature = "no_closure")]
let target_is_shared = false;
#[cfg(not(feature = "no_closure"))]
let target_is_shared = target.is_shared();
#[cfg(feature = "no_closure")]
let target_is_shared = false;
if target_is_shared {
lock_guard = target
.write_lock::<Dynamic>()
.expect("never fails when casting to `Dynamic`");
lhs_ptr_inner = &mut *lock_guard;
} else {
lhs_ptr_inner = &mut *target;
}
let hash = hash_op_assign;
let args = &mut [lhs_ptr_inner, &mut new_value];
match self.call_native_fn(mods, state, lib, op, hash, args, true, true, op_pos) {
Ok(_) => (),
Err(err) if matches!(err.as_ref(), EvalAltResult::ErrorFunctionNotFound(f, _) if f.starts_with(op)) =>
{
// Expand to `var = var op rhs`
let op = &op[..op.len() - 1]; // extract operator without =
// Run function
let (value, _) = self
.call_native_fn(mods, state, lib, op, hash_op, args, true, false, op_pos)?;
*args[0] = value.flatten();
if target_is_shared {
lock_guard = target
.write_lock::<Dynamic>()
.expect("never fails when casting to `Dynamic`");
lhs_ptr_inner = &mut *lock_guard;
} else {
lhs_ptr_inner = &mut *target;
}
let hash = hash_op_assign;
let args = &mut [lhs_ptr_inner, &mut new_val];
match self.call_native_fn(mods, state, lib, op, hash, args, true, true, op_pos) {
Err(err) if matches!(err.as_ref(), EvalAltResult::ErrorFunctionNotFound(f, _) if f.starts_with(op)) =>
{
// Expand to `var = var op rhs`
let op = &op[..op.len() - 1]; // extract operator without =
// Run function
let (value, _) = self.call_native_fn(
mods, state, lib, op, hash_op, args, true, false, op_pos,
)?;
*args[0] = value.flatten();
}
err => return err.map(|_| ()),
}
err => return err.map(|_| ()),
}
Ok(())
target.propagate_changed_value()?;
} else {
// Normal assignment
target.set_value(new_value, new_value_pos)?;
Ok(())
target.set_value(new_val, new_val_pos)?;
}
Ok(())
}
/// Evaluate a statement.

1
src/fn_call.rs
View File

@ -1400,6 +1400,7 @@ impl Engine {
arg_values[0] = target.take_or_clone().flatten();
args = arg_values.iter_mut().collect();
} else {
// Turn it into a method call only if the object is not shared and not a simple value
let (first, rest) = arg_values
.split_first_mut()
.expect("never fails because the arguments list is not empty");

96
src/optimize.rs
View File

@ -202,7 +202,7 @@ fn optimize_stmt_block(
match stmt {
// Add constant literals into the state
Stmt::Const(value_expr, x, _, _) => {
optimize_expr(value_expr, state);
optimize_expr(value_expr, state, false);
if value_expr.is_constant() {
state.push_var(
@ -214,7 +214,7 @@ fn optimize_stmt_block(
}
// Add variables into the state
Stmt::Let(value_expr, x, _, _) => {
optimize_expr(value_expr, state);
optimize_expr(value_expr, state, false);
state.push_var(&x.name, AccessMode::ReadWrite, None);
}
// Optimize the statement
@ -392,10 +392,10 @@ fn optimize_stmt(stmt: &mut Stmt, state: &mut State, preserve_result: bool) {
// expr op= expr
Stmt::Assignment(x, _) => match x.0 {
Expr::Variable(_, _, _) => optimize_expr(&mut x.2, state),
Expr::Variable(_, _, _) => optimize_expr(&mut x.2, state, false),
_ => {
optimize_expr(&mut x.0, state);
optimize_expr(&mut x.2, state);
optimize_expr(&mut x.0, state, false);
optimize_expr(&mut x.2, state, false);
}
},
@ -405,7 +405,7 @@ fn optimize_stmt(stmt: &mut Stmt, state: &mut State, preserve_result: bool) {
let pos = condition.position();
let mut expr = mem::take(condition);
optimize_expr(&mut expr, state);
optimize_expr(&mut expr, state, false);
*stmt = if preserve_result {
// -> { expr, Noop }
@ -440,7 +440,7 @@ fn optimize_stmt(stmt: &mut Stmt, state: &mut State, preserve_result: bool) {
}
// if expr { if_block } else { else_block }
Stmt::If(condition, x, _) => {
optimize_expr(condition, state);
optimize_expr(condition, state, false);
let if_block = mem::take(x.0.statements()).into_vec();
*x.0.statements() =
optimize_stmt_block(if_block, state, preserve_result, true, false).into();
@ -462,7 +462,7 @@ fn optimize_stmt(stmt: &mut Stmt, state: &mut State, preserve_result: bool) {
if let Some(block) = table.get_mut(&hash) {
if let Some(mut condition) = mem::take(&mut block.0) {
// switch const { case if condition => stmt, _ => def } => if condition { stmt } else { def }
optimize_expr(&mut condition, state);
optimize_expr(&mut condition, state, false);
let def_block = mem::take(&mut *x.1).into_vec();
let def_stmt = optimize_stmt_block(def_block, state, true, true, false);
@ -502,12 +502,12 @@ fn optimize_stmt(stmt: &mut Stmt, state: &mut State, preserve_result: bool) {
}
// switch
Stmt::Switch(match_expr, x, _) => {
optimize_expr(match_expr, state);
optimize_expr(match_expr, state, false);
x.0.values_mut().for_each(|block| {
let condition = mem::take(&mut block.0).map_or_else(
|| Expr::Unit(Position::NONE),
|mut condition| {
optimize_expr(&mut condition, state);
optimize_expr(&mut condition, state, false);
condition
},
);
@ -550,7 +550,7 @@ fn optimize_stmt(stmt: &mut Stmt, state: &mut State, preserve_result: bool) {
}
// while expr { block }
Stmt::While(condition, body, _) => {
optimize_expr(condition, state);
optimize_expr(condition, state, false);
let block = mem::take(body.statements()).into_vec();
*body.statements() = optimize_stmt_block(block, state, false, true, false).into();
@ -587,21 +587,21 @@ fn optimize_stmt(stmt: &mut Stmt, state: &mut State, preserve_result: bool) {
}
// do { block } while|until expr
Stmt::Do(body, condition, _, _) => {
optimize_expr(condition, state);
optimize_expr(condition, state, false);
let block = mem::take(body.statements()).into_vec();
*body.statements() = optimize_stmt_block(block, state, false, true, false).into();
}
// for id in expr { block }
Stmt::For(iterable, x, _) => {
optimize_expr(iterable, state);
optimize_expr(iterable, state, false);
let body = mem::take(x.1.statements()).into_vec();
*x.1.statements() = optimize_stmt_block(body, state, false, true, false).into();
}
// let id = expr;
Stmt::Let(expr, _, _, _) => optimize_expr(expr, state),
Stmt::Let(expr, _, _, _) => optimize_expr(expr, state, false),
// import expr as var;
#[cfg(not(feature = "no_module"))]
Stmt::Import(expr, _, _) => optimize_expr(expr, state),
Stmt::Import(expr, _, _) => optimize_expr(expr, state, false),
// { block }
Stmt::Block(statements, pos) => {
let statements = mem::take(statements).into_vec();
@ -640,7 +640,7 @@ fn optimize_stmt(stmt: &mut Stmt, state: &mut State, preserve_result: bool) {
}
// func(...)
Stmt::Expr(expr @ Expr::FnCall(_, _)) => {
optimize_expr(expr, state);
optimize_expr(expr, state, false);
match expr {
Expr::FnCall(x, pos) => {
state.set_dirty();
@ -660,9 +660,9 @@ fn optimize_stmt(stmt: &mut Stmt, state: &mut State, preserve_result: bool) {
*stmt = mem::take(x.as_mut()).into();
}
// expr;
Stmt::Expr(expr) => optimize_expr(expr, state),
Stmt::Expr(expr) => optimize_expr(expr, state, false),
// return expr;
Stmt::Return(_, Some(ref mut expr), _) => optimize_expr(expr, state),
Stmt::Return(_, Some(ref mut expr), _) => optimize_expr(expr, state, false),
// All other statements - skip
_ => (),
@ -670,7 +670,7 @@ fn optimize_stmt(stmt: &mut Stmt, state: &mut State, preserve_result: bool) {
}
/// Optimize an [expression][Expr].
fn optimize_expr(expr: &mut Expr, state: &mut State) {
fn optimize_expr(expr: &mut Expr, state: &mut State, indexing: bool) {
// These keywords are handled specially
const DONT_EVAL_KEYWORDS: &[&str] = &[
KEYWORD_PRINT, // side effects
@ -693,7 +693,7 @@ fn optimize_expr(expr: &mut Expr, state: &mut State) {
}
// lhs.rhs
#[cfg(not(feature = "no_object"))]
Expr::Dot(x, _) => match (&mut x.lhs, &mut x.rhs) {
Expr::Dot(x, _) if !indexing => match (&mut x.lhs, &mut x.rhs) {
// map.string
(Expr::Map(m, pos), Expr::Property(p)) if m.0.iter().all(|(_, x)| x.is_pure()) => {
let prop = p.2.0.as_str();
@ -705,14 +705,17 @@ fn optimize_expr(expr: &mut Expr, state: &mut State) {
.unwrap_or_else(|| Expr::Unit(*pos));
}
// var.rhs
(Expr::Variable(_, _, _), rhs) => optimize_expr(rhs, state),
(Expr::Variable(_, _, _), rhs) => optimize_expr(rhs, state, true),
// lhs.rhs
(lhs, rhs) => { optimize_expr(lhs, state); optimize_expr(rhs, state); }
(lhs, rhs) => { optimize_expr(lhs, state, false); optimize_expr(rhs, state, true); }
}
// ....lhs.rhs
#[cfg(not(feature = "no_object"))]
Expr::Dot(x, _) => { optimize_expr(&mut x.lhs, state, false); optimize_expr(&mut x.rhs, state, indexing); }
// lhs[rhs]
#[cfg(not(feature = "no_index"))]
Expr::Index(x, _) => match (&mut x.lhs, &mut x.rhs) {
Expr::Index(x, _) if !indexing => match (&mut x.lhs, &mut x.rhs) {
// array[int]
(Expr::Array(a, pos), Expr::IntegerConstant(i, _))
if *i >= 0 && (*i as usize) < a.len() && a.iter().all(Expr::is_pure) =>
@ -744,6 +747,18 @@ fn optimize_expr(expr: &mut Expr, state: &mut State) {
.map(|(_, mut expr)| { expr.set_position(*pos); expr })
.unwrap_or_else(|| Expr::Unit(*pos));
}
// int[int]
(Expr::IntegerConstant(n, pos), Expr::IntegerConstant(i, _)) if *i >= 0 && (*i as usize) < (std::mem::size_of_val(n) * 8) => {
// Bit-field literal indexing - get the bit
state.set_dirty();
*expr = Expr::BoolConstant((*n & (1 << (*i as usize))) != 0, *pos);
}
// int[-int]
(Expr::IntegerConstant(n, pos), Expr::IntegerConstant(i, _)) if *i < 0 && i.checked_abs().map(|i| i as usize <= (std::mem::size_of_val(n) * 8)).unwrap_or(false) => {
// Bit-field literal indexing - get the bit
state.set_dirty();
*expr = Expr::BoolConstant((*n & (1 << (std::mem::size_of_val(n) * 8 - i.abs() as usize))) != 0, *pos);
}
// string[int]
(Expr::StringConstant(s, pos), Expr::IntegerConstant(i, _)) if *i >= 0 && (*i as usize) < s.chars().count() => {
// String literal indexing - get the character
@ -757,10 +772,13 @@ fn optimize_expr(expr: &mut Expr, state: &mut State) {
*expr = Expr::CharConstant(s.chars().rev().nth(i.abs() as usize - 1).unwrap(), *pos);
}
// var[rhs]
(Expr::Variable(_, _, _), rhs) => optimize_expr(rhs, state),
(Expr::Variable(_, _, _), rhs) => optimize_expr(rhs, state, true),
// lhs[rhs]
(lhs, rhs) => { optimize_expr(lhs, state); optimize_expr(rhs, state); }
(lhs, rhs) => { optimize_expr(lhs, state, false); optimize_expr(rhs, state, true); }
},
// ...[lhs][rhs]
#[cfg(not(feature = "no_index"))]
Expr::Index(x, _) => { optimize_expr(&mut x.lhs, state, false); optimize_expr(&mut x.rhs, state, indexing); }
// ``
Expr::InterpolatedString(x) if x.is_empty() => {
state.set_dirty();
@ -773,7 +791,7 @@ fn optimize_expr(expr: &mut Expr, state: &mut State) {
}
// `... ${ ... } ...`
Expr::InterpolatedString(x) => {
x.iter_mut().for_each(|expr| optimize_expr(expr, state));
x.iter_mut().for_each(|expr| optimize_expr(expr, state, false));
let mut n= 0;
@ -824,7 +842,7 @@ fn optimize_expr(expr: &mut Expr, state: &mut State) {
}
// [ items .. ]
#[cfg(not(feature = "no_index"))]
Expr::Array(x, _) => x.iter_mut().for_each(|expr| optimize_expr(expr, state)),
Expr::Array(x, _) => x.iter_mut().for_each(|expr| optimize_expr(expr, state, false)),
// #{ key:constant, .. }
#[cfg(not(feature = "no_object"))]
Expr::Map(_, _) if expr.is_constant() => {
@ -833,13 +851,13 @@ fn optimize_expr(expr: &mut Expr, state: &mut State) {
}
// #{ key:value, .. }
#[cfg(not(feature = "no_object"))]
Expr::Map(x, _) => x.0.iter_mut().for_each(|(_, expr)| optimize_expr(expr, state)),
Expr::Map(x, _) => x.0.iter_mut().for_each(|(_, expr)| optimize_expr(expr, state, false)),
// lhs && rhs
Expr::And(x, _) => match (&mut x.lhs, &mut x.rhs) {
// true && rhs -> rhs
(Expr::BoolConstant(true, _), rhs) => {
state.set_dirty();
optimize_expr(rhs, state);
optimize_expr(rhs, state, false);
*expr = mem::take(rhs);
}
// false && rhs -> false
@ -850,18 +868,18 @@ fn optimize_expr(expr: &mut Expr, state: &mut State) {
// lhs && true -> lhs
(lhs, Expr::BoolConstant(true, _)) => {
state.set_dirty();
optimize_expr(lhs, state);
optimize_expr(lhs, state, false);
*expr = mem::take(lhs);
}
// lhs && rhs
(lhs, rhs) => { optimize_expr(lhs, state); optimize_expr(rhs, state); }
(lhs, rhs) => { optimize_expr(lhs, state, false); optimize_expr(rhs, state, false); }
},
// lhs || rhs
Expr::Or(ref mut x, _) => match (&mut x.lhs, &mut x.rhs) {
// false || rhs -> rhs
(Expr::BoolConstant(false, _), rhs) => {
state.set_dirty();
optimize_expr(rhs, state);
optimize_expr(rhs, state, false);
*expr = mem::take(rhs);
}
// true || rhs -> true
@ -872,11 +890,11 @@ fn optimize_expr(expr: &mut Expr, state: &mut State) {
// lhs || false
(lhs, Expr::BoolConstant(false, _)) => {
state.set_dirty();
optimize_expr(lhs, state);
optimize_expr(lhs, state, false);
*expr = mem::take(lhs);
}
// lhs || rhs
(lhs, rhs) => { optimize_expr(lhs, state); optimize_expr(rhs, state); }
(lhs, rhs) => { optimize_expr(lhs, state, false); optimize_expr(rhs, state, false); }
},
// eval!
@ -899,7 +917,7 @@ fn optimize_expr(expr: &mut Expr, state: &mut State) {
// Do not call some special keywords
Expr::FnCall(x, _) if DONT_EVAL_KEYWORDS.contains(&x.name.as_ref()) => {
x.args.iter_mut().for_each(|a| optimize_expr(a, state));
x.args.iter_mut().for_each(|a| optimize_expr(a, state, false));
}
// Call built-in operators
@ -933,7 +951,7 @@ fn optimize_expr(expr: &mut Expr, state: &mut State) {
}
}
x.args.iter_mut().for_each(|a| optimize_expr(a, state));
x.args.iter_mut().for_each(|a| optimize_expr(a, state, false));
// Move constant arguments to the right
while x.args.last().map(Expr::is_constant).unwrap_or(false) {
@ -989,12 +1007,12 @@ fn optimize_expr(expr: &mut Expr, state: &mut State) {
}
}
x.args.iter_mut().for_each(|a| optimize_expr(a, state));
x.args.iter_mut().for_each(|a| optimize_expr(a, state, false));
}
// id(args ..) -> optimize function call arguments
Expr::FnCall(x, _) => {
x.args.iter_mut().for_each(|a| optimize_expr(a, state));
x.args.iter_mut().for_each(|a| optimize_expr(a, state, false));
// Move constant arguments to the right
while x.args.last().map(Expr::is_constant).unwrap_or(false) {
@ -1021,7 +1039,7 @@ fn optimize_expr(expr: &mut Expr, state: &mut State) {
if x.scope_changed {
state.propagate_constants = false;
}
x.keywords.iter_mut().for_each(|expr| optimize_expr(expr, state));
x.keywords.iter_mut().for_each(|expr| optimize_expr(expr, state, false));
}
// All other expressions - skip

90
src/packages/iter_basic.rs
View File

@ -1,5 +1,5 @@
use crate::dynamic::Variant;
use crate::{def_package, EvalAltResult, INT};
use crate::{def_package, EvalAltResult, Position, INT};
use std::ops::Range;
#[cfg(feature = "no_std")]
use std::prelude::v1::*;
@ -29,9 +29,9 @@ where
Default::default(),
Box::new(EvalAltResult::ErrorArithmetic(
"step value cannot be zero".to_string(),
crate::Position::NONE,
Position::NONE,
)),
crate::Position::NONE,
Position::NONE,
)
.into();
}
@ -126,6 +126,68 @@ where
}
}
// Register range function with step
#[derive(Debug, Clone, Copy, Hash, Eq, PartialEq)]
struct BitRange(INT, INT, usize);
const BITS: usize = std::mem::size_of::<INT>() * 8;
impl BitRange {
pub fn new(value: INT, from: INT, len: INT) -> Result<Self, Box<EvalAltResult>> {
let from = if from >= 0 {
let offset = from as usize;
#[cfg(not(feature = "unchecked"))]
if offset >= BITS {
return EvalAltResult::ErrorBitFieldBounds(BITS, from, Position::NONE).into();
}
offset
} else {
#[cfg(not(feature = "unchecked"))]
if let Some(abs_from) = from.checked_abs() {
if (abs_from as usize) > BITS {
return EvalAltResult::ErrorBitFieldBounds(BITS, from, Position::NONE).into();
}
BITS - (abs_from as usize)
} else {
return EvalAltResult::ErrorBitFieldBounds(BITS, from, Position::NONE).into();
}
#[cfg(feature = "unchecked")]
{
BITS - (from.abs() as usize)
}
};
let len = if len < 0 {
0
} else if from + (len as usize) > BITS {
BITS - from
} else {
len as usize
};
Ok(Self(value, 1 << from, len))
}
}
impl Iterator for BitRange {
type Item = bool;
fn next(&mut self) -> Option<Self::Item> {
let Self(value, mask, len) = *self;
if len == 0 {
None
} else {
let r = (value & mask) != 0;
self.1 <<= 1;
self.2 -= 1;
Some(r)
}
}
}
macro_rules! reg_range {
($lib:ident | $x:expr => $( $y:ty ),*) => {
$(
@ -193,8 +255,8 @@ def_package!(crate:BasicIteratorPackage:"Basic range iterators.", lib, {
#[cfg(not(feature = "unchecked"))]
if step == 0.0 {
return EvalAltResult::ErrorInFunctionCall("range".to_string(), "".to_string(),
Box::new(EvalAltResult::ErrorArithmetic("step value cannot be zero".to_string(), crate::Position::NONE)),
crate::Position::NONE,
Box::new(EvalAltResult::ErrorArithmetic("step value cannot be zero".to_string(), Position::NONE)),
Position::NONE,
).into();
}
@ -255,8 +317,8 @@ def_package!(crate:BasicIteratorPackage:"Basic range iterators.", lib, {
#[cfg(not(feature = "unchecked"))]
if step.is_zero() {
return EvalAltResult::ErrorInFunctionCall("range".to_string(), "".to_string(),
Box::new(EvalAltResult::ErrorArithmetic("step value cannot be zero".to_string(), crate::Position::NONE)),
crate::Position::NONE,
Box::new(EvalAltResult::ErrorArithmetic("step value cannot be zero".to_string(), Position::NONE)),
Position::NONE,
).into();
}
@ -304,4 +366,18 @@ def_package!(crate:BasicIteratorPackage:"Basic range iterators.", lib, {
#[cfg(feature = "metadata")]
lib.update_fn_metadata(_hash, &["from: Decimal", "to: Decimal", "step: Decimal", "Iterator<Item=Decimal>"]);
}
lib.set_iterator::<BitRange>();
let _hash = lib.set_native_fn("bits", |value, from, len| BitRange::new(value, from, len));
#[cfg(feature = "metadata")]
lib.update_fn_metadata(_hash, &["value: INT", "from: Decimal", "len: Decimal", "Iterator<Item=bool>"]);
let _hash = lib.set_native_fn("bits", |value, from| BitRange::new(value, from, INT::MAX));
#[cfg(feature = "metadata")]
lib.update_fn_metadata(_hash, &["value: INT", "from: Decimal", "Iterator<Item=bool>"]);
let _hash = lib.set_native_fn("bits", |value| BitRange::new(value, 0, INT::MAX));
#[cfg(feature = "metadata")]
lib.update_fn_metadata(_hash, &["value: INT", "Iterator<Item=bool>"]);
});

164
src/packages/logic.rs
View File

@ -1,7 +1,7 @@
#![allow(non_snake_case)]
use crate::def_package;
use crate::plugin::*;
use crate::{def_package, EvalAltResult, INT};
#[cfg(feature = "no_std")]
use std::prelude::v1::*;
@ -59,6 +59,8 @@ def_package!(crate:LogicPackage:"Logical operators.", lib, {
}
set_exported_fn!(lib, "!", not);
combine_with_exported_module!(lib, "bit_field", bit_field_functions);
});
// Logic operators
@ -87,8 +89,6 @@ gen_cmp_functions!(float => f64);
#[cfg(not(feature = "no_float"))]
#[export_module]
mod f32_functions {
use crate::INT;
#[rhai_fn(name = "==")]
pub fn eq_if(x: INT, y: f32) -> bool {
(x as f32) == (y as f32)
@ -142,8 +142,6 @@ mod f32_functions {
#[cfg(not(feature = "no_float"))]
#[export_module]
mod f64_functions {
use crate::INT;
#[rhai_fn(name = "==")]
pub fn eq_if(x: INT, y: f64) -> bool {
(x as f64) == (y as f64)
@ -193,3 +191,159 @@ mod f64_functions {
(x as f64) <= (y as f64)
}
}
#[export_module]
mod bit_field_functions {
const BITS: usize = std::mem::size_of::<INT>() * 8;
#[rhai_fn(return_raw)]
pub fn get_bit(value: INT, index: INT) -> Result<bool, Box<EvalAltResult>> {
if index >= 0 {
let offset = index as usize;
if offset >= BITS {
EvalAltResult::ErrorBitFieldBounds(BITS, index, Position::NONE).into()
} else {
Ok((value & (1 << offset)) != 0)
}
} else if let Some(abs_index) = index.checked_abs() {
let offset = abs_index as usize;
// Count from end if negative
if offset > BITS {
EvalAltResult::ErrorBitFieldBounds(BITS, index, Position::NONE).into()
} else {
Ok((value & (1 << (BITS - offset))) != 0)
}
} else {
EvalAltResult::ErrorBitFieldBounds(BITS, index, Position::NONE).into()
}
}
#[rhai_fn(return_raw)]
pub fn set_bit(value: &mut INT, index: INT, new_value: bool) -> Result<(), Box<EvalAltResult>> {
if index >= 0 {
let offset = index as usize;
if offset >= BITS {
EvalAltResult::ErrorBitFieldBounds(BITS, index, Position::NONE).into()
} else {
let mask = 1 << offset;
if new_value {
*value |= mask;
} else {
*value &= !mask;
}
Ok(())
}
} else if let Some(abs_index) = index.checked_abs() {
let offset = abs_index as usize;
// Count from end if negative
if offset > BITS {
EvalAltResult::ErrorBitFieldBounds(BITS, index, Position::NONE).into()
} else {
let mask = 1 << offset;
if new_value {
*value |= mask;
} else {
*value &= !mask;
}
Ok(())
}
} else {
EvalAltResult::ErrorBitFieldBounds(BITS, index, Position::NONE).into()
}
}
#[rhai_fn(return_raw)]
pub fn get_bits(value: INT, index: INT, bits: INT) -> Result<INT, Box<EvalAltResult>> {
if bits < 1 {
return Ok(0);
}
let offset = if index >= 0 {
let offset = index as usize;
if offset >= BITS {
return EvalAltResult::ErrorBitFieldBounds(BITS, index, Position::NONE).into();
}
offset
} else if let Some(abs_index) = index.checked_abs() {
let offset = abs_index as usize;
// Count from end if negative
if offset > BITS {
return EvalAltResult::ErrorBitFieldBounds(BITS, index, Position::NONE).into();
}
BITS - offset
} else {
return EvalAltResult::ErrorBitFieldBounds(BITS, index, Position::NONE).into();
};
let bits = if offset + bits as usize > BITS {
BITS - offset
} else {
bits as usize
};
let mut base = 1;
let mut mask = 0;
for _ in 0..bits {
mask |= base;
base <<= 1;
}
Ok(((value & (mask << index)) >> index) & mask)
}
#[rhai_fn(return_raw)]
pub fn set_bits(
value: &mut INT,
index: INT,
bits: INT,
new_value: INT,
) -> Result<(), Box<EvalAltResult>> {
if bits < 1 {
return Ok(());
}
let offset = if index >= 0 {
let offset = index as usize;
if offset >= BITS {
return EvalAltResult::ErrorBitFieldBounds(BITS, index, Position::NONE).into();
}
offset
} else if let Some(abs_index) = index.checked_abs() {
let offset = abs_index as usize;
// Count from end if negative
if offset > BITS {
return EvalAltResult::ErrorBitFieldBounds(BITS, index, Position::NONE).into();
}
BITS - offset
} else {
return EvalAltResult::ErrorBitFieldBounds(BITS, index, Position::NONE).into();
};
let bits = if offset + bits as usize > BITS {
BITS - offset
} else {
bits as usize
};
let mut base = 1;
let mut mask = 0;
for _ in 0..bits {
mask |= base;
base <<= 1;
}
*value &= !(mask << index);
*value |= (new_value & mask) << index;
Ok(())
}
}

5
src/parser.rs
View File

@ -455,7 +455,10 @@ fn parse_index_chain(
// Check type of indexing - must be integer or string
match &idx_expr {
Expr::IntegerConstant(_, pos) => match lhs {
Expr::Array(_, _) | Expr::StringConstant(_, _) | Expr::InterpolatedString(_) => (),
Expr::IntegerConstant(_, _)
| Expr::Array(_, _)
| Expr::StringConstant(_, _)
| Expr::InterpolatedString(_) => (),
Expr::Map(_, _) => {
return Err(PERR::MalformedIndexExpr(

16
src/result.rs
View File

@ -56,6 +56,9 @@ pub enum EvalAltResult {
/// String indexing out-of-bounds.
/// Wrapped values are the current number of characters in the string and the index number.
ErrorStringBounds(usize, INT, Position),
/// Bit-field indexing out-of-bounds.
/// Wrapped values are the current number of bits in the bit-field and the index number.
ErrorBitFieldBounds(usize, INT, Position),
/// Trying to index into a type that is not an array, an object map, or a string, and has no
/// indexer function defined. Wrapped value is the type name.
ErrorIndexingType(String, Position),
@ -109,6 +112,7 @@ impl EvalAltResult {
Self::ErrorArrayBounds(_, _, _) => "Array index out of bounds",
Self::ErrorStringBounds(0, _, _) => "Empty string has nothing to index",
Self::ErrorStringBounds(_, _, _) => "String index out of bounds",
Self::ErrorBitFieldBounds(_, _, _) => "Bit-field index out of bounds",
Self::ErrorFor(_) => "For loop expects an array, object map, or range",
Self::ErrorVariableNotFound(_, _) => "Variable not found",
Self::ErrorModuleNotFound(_, _) => "Module not found",
@ -233,6 +237,11 @@ impl fmt::Display for EvalAltResult {
"String index {} out of bounds: only {} characters in the string",
index, max
)?,
Self::ErrorBitFieldBounds(max, index, _) => write!(
f,
"Bit-field index {} out of bounds: only {} bits in the bit-field",
index, max
)?,
Self::ErrorDataTooLarge(typ, _) => write!(f, "{} exceeds maximum limit", typ)?,
}
@ -289,6 +298,7 @@ impl EvalAltResult {
| Self::ErrorMismatchDataType(_, _, _)
| Self::ErrorArrayBounds(_, _, _)
| Self::ErrorStringBounds(_, _, _)
| Self::ErrorBitFieldBounds(_, _, _)
| Self::ErrorIndexingType(_, _)
| Self::ErrorFor(_)
| Self::ErrorVariableNotFound(_, _)
@ -372,7 +382,9 @@ impl EvalAltResult {
map.insert("requested".into(), r.into());
map.insert("actual".into(), a.into());
}
Self::ErrorArrayBounds(n, i, _) | Self::ErrorStringBounds(n, i, _) => {
Self::ErrorArrayBounds(n, i, _)
| Self::ErrorStringBounds(n, i, _)
| Self::ErrorBitFieldBounds(n, i, _) => {
map.insert("length".into(), (*n as INT).into());
map.insert("index".into(), (*i as INT).into());
}
@ -412,6 +424,7 @@ impl EvalAltResult {
| Self::ErrorMismatchDataType(_, _, pos)
| Self::ErrorArrayBounds(_, _, pos)
| Self::ErrorStringBounds(_, _, pos)
| Self::ErrorBitFieldBounds(_, _, pos)
| Self::ErrorIndexingType(_, pos)
| Self::ErrorFor(pos)
| Self::ErrorVariableNotFound(_, pos)
@ -452,6 +465,7 @@ impl EvalAltResult {
| Self::ErrorMismatchDataType(_, _, pos)
| Self::ErrorArrayBounds(_, _, pos)
| Self::ErrorStringBounds(_, _, pos)
| Self::ErrorBitFieldBounds(_, _, pos)
| Self::ErrorIndexingType(_, pos)
| Self::ErrorFor(pos)
| Self::ErrorVariableNotFound(_, pos)

35
tests/bit_shift.rs
View File

@ -13,3 +13,38 @@ fn test_right_shift() -> Result<(), Box<EvalAltResult>> {
assert_eq!(engine.eval::<INT>("9 >> 1")?, 4);
Ok(())
}
#[cfg(not(feature = "no_index"))]
#[test]
fn test_bit_fields() -> Result<(), Box<EvalAltResult>> {
let engine = Engine::new();
assert!(!engine.eval::<bool>("let x = 10; x[0]")?);
assert!(engine.eval::<bool>("let x = 10; x[1]")?);
assert!(!engine.eval::<bool>("let x = 10; x[-1]")?);
assert_eq!(
engine.eval::<INT>("let x = 10; x[0] = true; x[1] = false; x")?,
9
);
assert_eq!(engine.eval::<INT>("let x = 10; get_bits(x, 1, 3)")?, 5);
assert_eq!(
engine.eval::<INT>("let x = 10; set_bits(x, 1, 3, 7); x")?,
14
);
assert_eq!(
engine.eval::<INT>(
"
let x = 0b001101101010001;
let count = 0;
for b in bits(x, 2, 10) {
if b { count += 1; }
}
count
"
)?,
5
);
Ok(())
}