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Change AST nodes to use bitflags for options.

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This commit is contained in:
Stephen Chung 2021-08-03 22:19:25 +08:00
parent 8ea6424d50
commit 1d82a11f0b
6 changed files with 173 additions and 64 deletions
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140
src/ast.rs
View File

@ -16,7 +16,7 @@ use std::{
hash::Hash,
mem,
num::{NonZeroU8, NonZeroUsize},
ops::{Add, AddAssign, Deref, DerefMut},
ops::{Add, AddAssign, Deref, DerefMut, Not, Sub, SubAssign},
};
#[cfg(not(feature = "no_float"))]
@ -950,16 +950,108 @@ impl From<StmtBlock> for Stmt {
}
}
/// _(internals)_ Type of variable declaration.
/// A type that holds a configuration option with bit-flags.
/// Exported under the `internals` feature only.
///
/// # Volatile Data Structure
///
/// This type is volatile and may change.
#[derive(Debug, Eq, PartialEq, Copy, Clone, Hash)]
pub enum VarDeclaration {
Let,
Const,
#[derive(PartialEq, Eq, Copy, Clone, Hash, Default)]
pub struct BitOptions(u8);
impl BitOptions {
/// Does this [`BitOptions`] contain a particular option flag?
#[inline(always)]
pub const fn contains(self, flag: Self) -> bool {
self.0 & flag.0 != 0
}
}
impl Not for BitOptions {
type Output = Self;
fn not(self) -> Self::Output {
Self(!self.0)
}
}
impl Add for BitOptions {
type Output = Self;
#[inline(always)]
fn add(self, rhs: Self) -> Self::Output {
Self(self.0 | rhs.0)
}
}
impl AddAssign for BitOptions {
#[inline(always)]
fn add_assign(&mut self, rhs: Self) {
self.0 |= rhs.0
}
}
impl Sub for BitOptions {
type Output = Self;
#[inline(always)]
fn sub(self, rhs: Self) -> Self::Output {
Self(self.0 & !rhs.0)
}
}
impl SubAssign for BitOptions {
#[inline(always)]
fn sub_assign(&mut self, rhs: Self) {
self.0 &= !rhs.0
}
}
/// Option bit-flags for [`AST`] nodes.
#[allow(non_snake_case)]
pub mod AST_FLAGS {
use super::BitOptions;
/// _(internals)_ No options for the [`AST`][crate::AST] node.
/// Exported under the `internals` feature only.
pub const AST_FLAG_NONE: BitOptions = BitOptions(0b0000_0000);
/// _(internals)_ The [`AST`][crate::AST] node is constant.
/// Exported under the `internals` feature only.
pub const AST_FLAG_CONSTANT: BitOptions = BitOptions(0b0000_0001);
/// _(internals)_ The [`AST`][crate::AST] node is exported.
/// Exported under the `internals` feature only.
pub const AST_FLAG_EXPORTED: BitOptions = BitOptions(0b0000_0010);
/// _(internals)_ The [`AST`][crate::AST] node is in negated mode.
/// Exported under the `internals` feature only.
pub const AST_FLAG_NEGATED: BitOptions = BitOptions(0b0000_0100);
impl std::fmt::Debug for BitOptions {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
let mut has_flags = false;
f.write_str("(")?;
if self.contains(AST_FLAG_CONSTANT) {
if has_flags {
f.write_str("+")?;
}
f.write_str("Constant")?;
has_flags = true;
}
if self.contains(AST_FLAG_EXPORTED) {
if has_flags {
f.write_str("+")?;
}
f.write_str("Exported")?;
has_flags = true;
}
if self.contains(AST_FLAG_NEGATED) {
if has_flags {
f.write_str("+")?;
}
f.write_str("Negated")?;
//has_flags = true;
}
f.write_str(")")?;
Ok(())
}
}
}
/// _(internals)_ A statement.
@ -983,11 +1075,21 @@ pub enum Stmt {
/// `while` expr `{` stmt `}`
While(Expr, Box<StmtBlock>, Position),
/// `do` `{` stmt `}` `while`|`until` expr
Do(Box<StmtBlock>, Expr, bool, Position),
///
/// ### Option flags
///
/// * [`AST_FLAG_NONE`][AST_FLAGS::AST_FLAG_NONE] = `while`
/// * [`AST_FLAG_NEGATED`][AST_FLAGS::AST_FLAG_NEGATED] = `until`
Do(Box<StmtBlock>, Expr, BitOptions, Position),
/// `for` `(` id `,` counter `)` `in` expr `{` stmt `}`
For(Expr, Box<(Ident, Option<Ident>, StmtBlock)>, Position),
/// \[`export`\] `let`/`const` id `=` expr
Var(Expr, Box<Ident>, VarDeclaration, bool, Position),
///
/// ### Option flags
///
/// * [`AST_FLAG_EXPORTED`][AST_FLAGS::AST_FLAG_EXPORTED] = `export`
/// * [`AST_FLAG_CONSTANT`][AST_FLAGS::AST_FLAG_CONSTANT] = `const`
Var(Expr, Box<Ident>, BitOptions, Position),
/// expr op`=` expr
Assignment(Box<(Expr, Option<OpAssignment<'static>>, Expr)>, Position),
/// func `(` expr `,` ... `)`
@ -1068,7 +1170,7 @@ impl Stmt {
| Self::Do(_, _, _, pos)
| Self::For(_, _, pos)
| Self::Return(_, _, pos)
| Self::Var(_, _, _, _, pos)
| Self::Var(_, _, _, pos)
| Self::TryCatch(_, pos) => *pos,
Self::Expr(x) => x.position(),
@ -1097,7 +1199,7 @@ impl Stmt {
| Self::Do(_, _, _, pos)
| Self::For(_, _, pos)
| Self::Return(_, _, pos)
| Self::Var(_, _, _, _, pos)
| Self::Var(_, _, _, pos)
| Self::TryCatch(_, pos) => *pos = new_pos,
Self::Expr(x) => {
@ -1131,7 +1233,7 @@ impl Stmt {
| Self::For(_, _, _)
| Self::TryCatch(_, _) => false,
Self::Var(_, _, _, _, _)
Self::Var(_, _, _, _)
| Self::Assignment(_, _)
| Self::Continue(_)
| Self::Break(_)
@ -1158,7 +1260,7 @@ impl Stmt {
// A No-op requires a semicolon in order to know it is an empty statement!
Self::Noop(_) => false,
Self::Var(_, _, _, _, _)
Self::Var(_, _, _, _)
| Self::Assignment(_, _)
| Self::FnCall(_, _)
| Self::Expr(_)
@ -1199,7 +1301,7 @@ impl Stmt {
condition.is_pure() && block.0.iter().all(Stmt::is_pure)
}
Self::For(iterable, x, _) => iterable.is_pure() && (x.2).0.iter().all(Stmt::is_pure),
Self::Var(_, _, _, _, _) | Self::Assignment(_, _) | Self::FnCall(_, _) => false,
Self::Var(_, _, _, _) | Self::Assignment(_, _) | Self::FnCall(_, _) => false,
Self::Block(block, _) => block.iter().all(|stmt| stmt.is_pure()),
Self::Continue(_) | Self::Break(_) | Self::Return(_, _, _) => false,
Self::TryCatch(x, _) => {
@ -1225,7 +1327,7 @@ impl Stmt {
#[must_use]
pub fn is_internally_pure(&self) -> bool {
match self {
Self::Var(expr, _, _, _, _) => expr.is_pure(),
Self::Var(expr, _, _, _) => expr.is_pure(),
#[cfg(not(feature = "no_module"))]
Self::Import(expr, _, _) => expr.is_pure(),
@ -1263,7 +1365,7 @@ impl Stmt {
}
match self {
Self::Var(e, _, _, _, _) => {
Self::Var(e, _, _, _) => {
if !e.walk(path, on_node) {
return false;
}

22
src/engine.rs
View File

@ -1,6 +1,6 @@
//! Main module defining the script evaluation [`Engine`].
use crate::ast::{Expr, FnCallExpr, Ident, OpAssignment, ReturnType, Stmt, VarDeclaration};
use crate::ast::{Expr, FnCallExpr, Ident, OpAssignment, ReturnType, Stmt, AST_FLAGS::*};
use crate::custom_syntax::CustomSyntax;
use crate::dynamic::{map_std_type_name, AccessMode, Union, Variant};
use crate::fn_hash::get_hasher;
@ -2569,7 +2569,9 @@ impl Engine {
},
// Do loop
Stmt::Do(body, expr, is_while, _) => loop {
Stmt::Do(body, expr, flags, _) => loop {
let is_while = !flags.contains(AST_FLAG_NEGATED);
if !body.is_empty() {
match self.eval_stmt_block(scope, mods, state, lib, this_ptr, body, true, level)
{
@ -2587,7 +2589,7 @@ impl Engine {
.as_bool()
.map_err(|typ| self.make_type_mismatch_err::<bool>(typ, expr.position()))?;
if condition ^ *is_while {
if condition ^ is_while {
return Ok(Dynamic::UNIT);
}
},
@ -2851,12 +2853,14 @@ impl Engine {
}
// Let/const statement
Stmt::Var(expr, x, var_type, export, _) => {
Stmt::Var(expr, x, flags, _) => {
let name = &x.name;
let entry_type = match var_type {
VarDeclaration::Let => AccessMode::ReadWrite,
VarDeclaration::Const => AccessMode::ReadOnly,
let entry_type = if flags.contains(AST_FLAG_CONSTANT) {
AccessMode::ReadOnly
} else {
AccessMode::ReadWrite
};
let export = flags.contains(AST_FLAG_EXPORTED);
let value = self
.eval_expr(scope, mods, state, lib, this_ptr, expr, level)?
@ -2893,9 +2897,9 @@ impl Engine {
(
name.to_string().into(),
if *export { Some(name.clone()) } else { None },
if export { Some(name.clone()) } else { None },
)
} else if *export {
} else if export {
unreachable!("exported variable not on global level");
} else {
(unsafe_cast_var_name_to_lifetime(name).into(), None)

4
src/lib.rs
View File

@ -227,8 +227,8 @@ pub use token::{InputStream, Token, TokenizeState, TokenizerControl, TokenizerCo
#[cfg(feature = "internals")]
#[deprecated = "this type is volatile and may change"]
pub use ast::{
ASTNode, BinaryExpr, CustomExpr, Expr, FloatWrapper, FnCallExpr, FnCallHashes, Ident,
OpAssignment, ReturnType, ScriptFnDef, Stmt, StmtBlock, VarDeclaration,
ASTNode, BinaryExpr, BitOptions, CustomExpr, Expr, FloatWrapper, FnCallExpr, FnCallHashes,
Ident, OpAssignment, ReturnType, ScriptFnDef, Stmt, StmtBlock, AST_FLAGS::*,
};
#[cfg(feature = "internals")]

20
src/optimize.rs
View File

@ -1,6 +1,6 @@
//! Module implementing the [`AST`] optimizer.
use crate::ast::{Expr, OpAssignment, Stmt, VarDeclaration};
use crate::ast::{Expr, OpAssignment, Stmt, AST_FLAGS::*};
use crate::dynamic::AccessMode;
use crate::engine::{KEYWORD_DEBUG, KEYWORD_EVAL, KEYWORD_FN_PTR, KEYWORD_PRINT, KEYWORD_TYPE_OF};
use crate::fn_builtin::get_builtin_binary_op_fn;
@ -201,8 +201,9 @@ fn optimize_stmt_block(
// Optimize each statement in the block
statements.iter_mut().for_each(|stmt| {
match stmt {
Stmt::Var(value_expr, x, flags, _) => {
if flags.contains(AST_FLAG_CONSTANT) {
// Add constant literals into the state
Stmt::Var(value_expr, x, VarDeclaration::Const, _, _) => {
optimize_expr(value_expr, state, false);
if value_expr.is_constant() {
@ -212,12 +213,12 @@ fn optimize_stmt_block(
value_expr.get_literal_value(),
);
}
}
} else {
// Add variables into the state
Stmt::Var(value_expr, x, VarDeclaration::Let, _, _) => {
optimize_expr(value_expr, state, false);
state.push_var(&x.name, AccessMode::ReadWrite, None);
}
}
// Optimize the statement
_ => optimize_stmt(stmt, state, preserve_result),
}
@ -232,7 +233,7 @@ fn optimize_stmt_block(
.find_map(|(i, stmt)| match stmt {
stmt if !is_pure(stmt) => Some(i),
Stmt::Var(e, _, _, _, _) | Stmt::Expr(e) if !e.is_constant() => Some(i),
Stmt::Var(e, _, _, _) | Stmt::Expr(e) if !e.is_constant() => Some(i),
#[cfg(not(feature = "no_module"))]
Stmt::Import(e, _, _) if !e.is_constant() => Some(i),
@ -582,8 +583,9 @@ fn optimize_stmt(stmt: &mut Stmt, state: &mut OptimizerState, preserve_result: b
}
}
// do { block } while false | do { block } until true -> { block }
Stmt::Do(body, Expr::BoolConstant(true, _), false, _)
| Stmt::Do(body, Expr::BoolConstant(false, _), true, _) => {
Stmt::Do(body, Expr::BoolConstant(x, _), flags, _)
if *x == flags.contains(AST_FLAG_NEGATED) =>
{
state.set_dirty();
let block_pos = body.position();
let block = mem::take(body.statements_mut()).into_vec();
@ -605,7 +607,9 @@ fn optimize_stmt(stmt: &mut Stmt, state: &mut OptimizerState, preserve_result: b
*x.2.statements_mut() = optimize_stmt_block(body, state, false, true, false).into();
}
// let id = expr;
Stmt::Var(expr, _, VarDeclaration::Let, _, _) => optimize_expr(expr, state, false),
Stmt::Var(expr, _, flags, _) if !flags.contains(AST_FLAG_CONSTANT) => {
optimize_expr(expr, state, false)
}
// import expr as var;
#[cfg(not(feature = "no_module"))]
Stmt::Import(expr, _, _) => optimize_expr(expr, state, false),

27
src/parse.rs
View File

@ -2,7 +2,7 @@
use crate::ast::{
BinaryExpr, CustomExpr, Expr, FnCallExpr, FnCallHashes, Ident, OpAssignment, ReturnType,
ScriptFnDef, Stmt, StmtBlock, VarDeclaration,
ScriptFnDef, Stmt, StmtBlock, AST_FLAGS::*,
};
use crate::custom_syntax::{
CustomSyntax, CUSTOM_SYNTAX_MARKER_BLOCK, CUSTOM_SYNTAX_MARKER_BOOL, CUSTOM_SYNTAX_MARKER_EXPR,
@ -2224,9 +2224,9 @@ fn parse_do(
settings.is_breakable = true;
let body = parse_block(input, state, lib, settings.level_up())?;
let is_while = match input.next().expect(NEVER_ENDS) {
(Token::While, _) => true,
(Token::Until, _) => false,
let negated = match input.next().expect(NEVER_ENDS) {
(Token::While, _) => AST_FLAG_NONE,
(Token::Until, _) => AST_FLAG_NEGATED,
(_, pos) => {
return Err(
PERR::MissingToken(Token::While.into(), "for the do statement".into())
@ -2244,7 +2244,7 @@ fn parse_do(
Ok(Stmt::Do(
Box::new(body.into()),
guard,
is_while,
negated,
settings.pos,
))
}
@ -2381,21 +2381,20 @@ fn parse_let(
state.stack.push((name, var_type));
let export = if export {
AST_FLAG_EXPORTED
} else {
AST_FLAG_NONE
};
match var_type {
// let name = expr
AccessMode::ReadWrite => Ok(Stmt::Var(
expr,
var_def.into(),
VarDeclaration::Let,
export,
settings.pos,
)),
AccessMode::ReadWrite => Ok(Stmt::Var(expr, var_def.into(), export, settings.pos)),
// const name = { expr:constant }
AccessMode::ReadOnly => Ok(Stmt::Var(
expr,
var_def.into(),
VarDeclaration::Const,
export,
AST_FLAG_CONSTANT + export,
settings.pos,
)),
}

2
tests/optimizer.rs
View File

@ -86,7 +86,7 @@ fn test_optimizer_parse() -> Result<(), Box<EvalAltResult>> {
assert_eq!(
format!("{:?}", ast),
r#"AST { source: None, body: Block[Var(false @ 1:18, "DECISION" @ 1:7, Const, false, 1:1), Expr(123 @ 1:51)], functions: Module, resolver: None }"#
r#"AST { source: None, body: Block[Var(false @ 1:18, "DECISION" @ 1:7, (Constant), 1:1), Expr(123 @ 1:51)], functions: Module, resolver: None }"#
);
let ast = engine.compile("if 1 == 2 { 42 }")?;