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change from prefold to fold_listcomp, and simply the fold_listcomp

This commit is contained in:
CrescentonC 2021-07-16 18:13:38 +08:00
parent b961128367
commit 94ffe4dac2
1 changed files with 49 additions and 41 deletions

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@ -36,7 +36,7 @@ impl<'a> ast::fold::Fold<Option<Type>> for InferenceContext<'a> {
// pre-fold
let mut expr = node;
expr = match &expr.node {
ast::ExprKind::ListComp { .. } => self.prefold_list_comprehension(expr)?,
ast::ExprKind::ListComp { .. } => self.fold_listcomp(expr)?,
_ => rustpython_parser::ast::fold::fold_expr(self, expr)?
};
@ -55,7 +55,7 @@ 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} => self.infer_list_comprehesion(elt, generators),
ast::ExprKind::ListComp {elt: _, generators: _} => Ok(expr.custom), // already folded
ast::ExprKind::Slice { .. } => Ok(None), // special handling for slice, which is supported
_ => Err("not supported yet".into())
}?,
@ -318,7 +318,7 @@ impl<'a> InferenceContext<'a> {
}
}
fn infer_list_comprehesion(&self, elt: &Box<ast::Expr<Option<Type>>>, generators: &Vec<ast::Comprehension<Option<Type>>>) -> Result<Option<Type>, String> {
fn _infer_list_comprehesion(&self, elt: &Box<ast::Expr<Option<Type>>>, generators: &Vec<ast::Comprehension<Option<Type>>>) -> Result<Option<Type>, String> {
if generators[0]
.ifs
.iter()
@ -332,35 +332,33 @@ impl<'a> InferenceContext<'a> {
}
// some pre-folds need special handling
fn prefold_list_comprehension(&mut self, expr: ast::Expr<Option<Type>>) -> Result<ast::Expr<Option<Type>>, String> {
fn fold_listcomp(&mut self, expr: ast::Expr<Option<Type>>) -> Result<ast::Expr<Option<Type>>, String> {
if let ast::Expr {
location,
custom,
custom: _,
node: ast::ExprKind::ListComp {
elt,
generators}} = expr {
mut generators}} = expr {
// if is list comprehension, need special pre-fold
if generators.len() != 1 {
return Err("only 1 generator statement is supported".into());
}
if generators[0].is_async {
let gen = generators.remove(0);
if gen.is_async {
return Err("async is not supported".into());
}
// fold iter first since it does not contain new identifiers
let generators_first_folded = generators
.into_iter()
.map(|x| -> Result<ast::Comprehension<Option<Type>>, String> {Ok(ast::Comprehension {
target: x.target,
iter: Box::new(self.fold_expr(*x.iter)?), // fold here
ifs: x.ifs,
is_async: x.is_async
})})
.collect::<Result<Vec<_>, _>>()?;
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
};
if let TypeEnum::ParametricType(
primitives::LIST_TYPE,
ls) = generators_first_folded[0]
ls) = gen_first_folded
.iter
.custom
.as_ref()
@ -368,29 +366,39 @@ impl<'a> InferenceContext<'a> {
.as_ref()
.clone() {
self.with_scope(|ctx| -> Result<ast::Expr<Option<Type>>, String> {
ctx.infer_simple_binding(&generators_first_folded[0].target, ls[0].clone())?;
Ok(ast::Expr {
location,
custom,
node: ast::ExprKind::ListComp { // now fold things with new name
elt:
Box::new(ctx.fold_expr(*elt)?),
generators:
generators_first_folded
.into_iter()
.map(|x| -> Result<ast::Comprehension<Option<Type>>, String> {Ok(ast::Comprehension {
target: Box::new(ctx.fold_expr(*x.target)?),
iter: x.iter,
ifs: x
ctx.infer_simple_binding(&gen_first_folded.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
.into_iter()
.map(|x| ctx.fold_expr(x))
.collect::<Result<Vec<_>, _>>()?,
is_async: x.is_async
})})
.collect::<Result<Vec<_>, _>>()?
.collect::<Result<Vec<ast::Expr<Option<Type>>>, _>>()?;
if ifs_folded
.iter()
.all(|x| x.custom == Some(ctx.get_primitive(primitives::BOOL_TYPE))) {
Ok(ast::Expr {
location,
custom: Some(TypeEnum::ParametricType(
primitives::LIST_TYPE,
vec![elt_folded
.custom
.clone()
.ok_or_else(|| "elements cannot be typped".to_string())?]).into()),
node: ast::ExprKind::ListComp {
elt: elt_folded,
generators: vec![ast::Comprehension {
target: target_folded,
ifs: ifs_folded,
iter: gen_first_folded.iter,
is_async: gen_first_folded.is_async
}]
}
})
} else {
Err("test must be bool".into())
}
}).1
} else {
Err("iteration is supported for list only".into())