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directly impl Fold<()> for InferenceContext

This commit is contained in:
CrescentonC 2021-07-19 12:03:13 +08:00
parent 94ffe4dac2
commit c7051fcc22
1 changed files with 20 additions and 42 deletions

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@ -8,8 +8,7 @@ use crate::typecheck::primitives;
use rustpython_parser::ast;
use rustpython_parser::ast::fold::Fold;
struct Premapper;
impl ast::fold::Fold<()> for Premapper {
impl<'a> ast::fold::Fold<()> for InferenceContext<'a> {
type TargetU = Option<Type>;
type Error = String;
@ -18,26 +17,11 @@ impl ast::fold::Fold<()> for Premapper {
}
fn fold_expr(&mut self, node: ast::Expr<()>) -> Result<ast::Expr<Self::TargetU>, Self::Error> {
ast::fold::fold_expr(self, node)
}
}
// assert_eq!(node.custom, None);
impl<'a> ast::fold::Fold<Option<Type>> for InferenceContext<'a> {
type TargetU = Option<Type>;
type Error = String;
fn map_user(&mut self, user: Option<Type>) -> Result<Self::TargetU, Self::Error> {
Ok(user)
}
fn fold_expr(&mut self, node: ast::Expr<Option<Type>>) -> Result<ast::Expr<Self::TargetU>, Self::Error> {
assert_eq!(node.custom, None);
// pre-fold
let mut expr = node;
expr = match &expr.node {
ast::ExprKind::ListComp { .. } => self.fold_listcomp(expr)?,
_ => rustpython_parser::ast::fold::fold_expr(self, expr)?
let expr = match &node.node {
ast::ExprKind::ListComp { .. } => self.fold_listcomp(node)?,
_ => rustpython_parser::ast::fold::fold_expr(self, node)?
};
Ok(ast::Expr {
@ -55,7 +39,7 @@ impl<'a> ast::fold::Fold<Option<Type>> for InferenceContext<'a> {
ast::ExprKind::Call {func, args, keywords} => self.infer_call(func, args, keywords),
ast::ExprKind::Subscript {value, slice, ctx: _} => self.infer_subscript(value, slice),
ast::ExprKind::IfExp {test, body, orelse} => self.infer_if_expr(test, body, orelse),
ast::ExprKind::ListComp {elt: _, generators: _} => Ok(expr.custom), // already folded
ast::ExprKind::ListComp {elt: _, generators: _} => panic!("should not earch here, the list comp should be folded before"), // already folded
ast::ExprKind::Slice { .. } => Ok(None), // special handling for slice, which is supported
_ => Err("not supported yet".into())
}?,
@ -332,7 +316,7 @@ impl<'a> InferenceContext<'a> {
}
// some pre-folds need special handling
fn fold_listcomp(&mut self, expr: ast::Expr<Option<Type>>) -> Result<ast::Expr<Option<Type>>, String> {
fn fold_listcomp(&mut self, expr: ast::Expr<()>) -> Result<ast::Expr<Option<Type>>, String> {
if let ast::Expr {
location,
custom: _,
@ -348,29 +332,25 @@ impl<'a> InferenceContext<'a> {
return Err("async is not supported".into());
}
// fold iter first since it does not contain new identifiers
let gen_first_folded = ast::Comprehension {
target: gen.target,
iter: Box::new(self.fold_expr(*gen.iter)?), // fold here
ifs: gen.ifs,
is_async: gen.is_async
};
let ast::Comprehension {iter,
target,
ifs,
is_async} = gen;
let iter_folded = Box::new(self.fold_expr(*iter)?);
if let TypeEnum::ParametricType(
primitives::LIST_TYPE,
ls) = gen_first_folded
.iter
ls) = iter_folded
.custom
.as_ref()
.ok_or_else(|| "no value".to_string())?
.as_ref()
.clone() {
self.with_scope(|ctx| -> Result<ast::Expr<Option<Type>>, String> {
ctx.infer_simple_binding(&gen_first_folded.target, ls[0].clone())?;
ctx.infer_simple_binding(&target, ls[0].clone())?;
let elt_folded = Box::new(ctx.fold_expr(*elt)?);
let target_folded = Box::new(ctx.fold_expr(*gen_first_folded.target)?);
let ifs_folded = gen_first_folded
.ifs
let target_folded = Box::new(ctx.fold_expr(*target)?);
let ifs_folded = ifs
.into_iter()
.map(|x| ctx.fold_expr(x))
.collect::<Result<Vec<ast::Expr<Option<Type>>>, _>>()?;
@ -391,8 +371,8 @@ impl<'a> InferenceContext<'a> {
generators: vec![ast::Comprehension {
target: target_folded,
ifs: ifs_folded,
iter: gen_first_folded.iter,
is_async: gen_first_folded.is_async
iter: iter_folded,
is_async: is_async
}]
}
})
@ -408,7 +388,7 @@ impl<'a> InferenceContext<'a> {
}
}
fn infer_simple_binding(&mut self, name: &ast::Expr<Option<Type>>, ty: Type) -> Result<(), String> {
fn infer_simple_binding<T>(&mut self, name: &ast::Expr<T>, ty: Type) -> Result<(), String> {
match &name.node {
ast::ExprKind::Name {id, ctx: _} => {
if id == "_" {
@ -445,7 +425,6 @@ pub struct ExpressionInferencer<'a> {
}
impl<'a> ExpressionInferencer<'a> {
pub fn fold_expr(&mut self, expr: ast::Expr) -> Result<ast::Expr<Option<Type>>, String> {
let expr = Premapper.fold_expr(expr)?;
self.ctx.fold_expr(expr)
}
}
@ -653,7 +632,7 @@ pub mod test {
let ast12 = rustpython_parser::parser::parse_expression("(1, True, 3, False)[1]").unwrap();
let folded = inf.fold_expr(ast1).unwrap();
let folded_2 = Premapper.fold_expr(ast2).unwrap();
let folded_2 = inf.fold_expr(ast2).unwrap();
let folded_3 = inf.fold_expr(ast3).unwrap();
let folded_4 = inf.fold_expr(ast4).unwrap();
let folded_5 = inf.fold_expr(ast5).unwrap();
@ -677,6 +656,5 @@ pub mod test {
println!("{:?}", folded_10.custom);
println!("{:?}", folded_11.custom);
println!("{:?}", folded_12.custom);
}
}