diff options
Diffstat (limited to 'users/glittershark/achilles/src/passes/hir/strip_positive_units.rs')
-rw-r--r-- | users/glittershark/achilles/src/passes/hir/strip_positive_units.rs | 189 |
1 files changed, 0 insertions, 189 deletions
diff --git a/users/glittershark/achilles/src/passes/hir/strip_positive_units.rs b/users/glittershark/achilles/src/passes/hir/strip_positive_units.rs deleted file mode 100644 index 91b56551c82d..000000000000 --- a/users/glittershark/achilles/src/passes/hir/strip_positive_units.rs +++ /dev/null @@ -1,189 +0,0 @@ -use std::collections::HashMap; -use std::mem; - -use ast::hir::Binding; -use ast::Literal; -use void::{ResultVoidExt, Void}; - -use crate::ast::hir::{Decl, Expr}; -use crate::ast::{self, Ident}; - -use super::Visitor; - -/// Strip all values with a unit type in positive (non-return) position -pub(crate) struct StripPositiveUnits {} - -impl<'a, 'ast> Visitor<'a, 'ast, ast::Type<'ast>> for StripPositiveUnits { - type Error = Void; - - fn pre_visit_expr( - &mut self, - expr: &mut Expr<'ast, ast::Type<'ast>>, - ) -> Result<(), Self::Error> { - let mut extracted = vec![]; - if let Expr::Call { args, .. } = expr { - // TODO(grfn): replace with drain_filter once it's stabilized - let mut i = 0; - while i != args.len() { - if args[i].type_() == &ast::Type::Unit { - let expr = args.remove(i); - if !matches!(expr, Expr::Literal(Literal::Unit, _)) { - extracted.push(expr) - }; - } else { - i += 1 - } - } - } - - if !extracted.is_empty() { - let body = mem::replace(expr, Expr::Literal(Literal::Unit, ast::Type::Unit)); - *expr = Expr::Let { - bindings: extracted - .into_iter() - .map(|expr| Binding { - ident: Ident::from_str_unchecked("___discarded"), - type_: expr.type_().clone(), - body: expr, - }) - .collect(), - type_: body.type_().clone(), - body: Box::new(body), - }; - } - - Ok(()) - } - - fn post_visit_call( - &mut self, - _fun: &mut Expr<'ast, ast::Type<'ast>>, - _type_args: &mut HashMap<Ident<'ast>, ast::Type<'ast>>, - args: &mut Vec<Expr<'ast, ast::Type<'ast>>>, - ) -> Result<(), Self::Error> { - args.retain(|arg| arg.type_() != &ast::Type::Unit); - Ok(()) - } - - fn visit_type(&mut self, type_: &mut ast::Type<'ast>) -> Result<(), Self::Error> { - if let ast::Type::Function(ft) = type_ { - ft.args.retain(|a| a != &ast::Type::Unit); - } - Ok(()) - } - - fn post_visit_fun_decl( - &mut self, - _name: &mut Ident<'ast>, - _type_args: &mut Vec<Ident>, - args: &mut Vec<(Ident, ast::Type<'ast>)>, - _body: &mut Box<Expr<ast::Type<'ast>>>, - _type_: &mut ast::Type<'ast>, - ) -> Result<(), Self::Error> { - args.retain(|(_, ty)| ty != &ast::Type::Unit); - Ok(()) - } -} - -pub(crate) fn run_toplevel<'a>(toplevel: &mut Vec<Decl<'a, ast::Type<'a>>>) { - let mut pass = StripPositiveUnits {}; - for decl in toplevel.iter_mut() { - pass.visit_decl(decl).void_unwrap(); - } -} - -#[cfg(test)] -mod tests { - use super::*; - use crate::parser::toplevel; - use crate::tc::typecheck_toplevel; - use pretty_assertions::assert_eq; - - #[test] - fn unit_only_arg() { - let (_, program) = toplevel( - "ty f : fn () -> int - fn f _ = 1 - - ty main : fn -> int - fn main = f ()", - ) - .unwrap(); - - let (_, expected) = toplevel( - "ty f : fn -> int - fn f = 1 - - ty main : fn -> int - fn main = f()", - ) - .unwrap(); - let expected = typecheck_toplevel(expected).unwrap(); - - let mut program = typecheck_toplevel(program).unwrap(); - run_toplevel(&mut program); - - assert_eq!(program, expected); - } - - #[test] - fn unit_and_other_arg() { - let (_, program) = toplevel( - "ty f : fn (), int -> int - fn f _ x = x - - ty main : fn -> int - fn main = f () 1", - ) - .unwrap(); - - let (_, expected) = toplevel( - "ty f : fn int -> int - fn f x = x - - ty main : fn -> int - fn main = f 1", - ) - .unwrap(); - let expected = typecheck_toplevel(expected).unwrap(); - - let mut program = typecheck_toplevel(program).unwrap(); - run_toplevel(&mut program); - - assert_eq!(program, expected); - } - - #[test] - fn unit_expr_and_other_arg() { - let (_, program) = toplevel( - "ty f : fn (), int -> int - fn f _ x = x - - ty g : fn int -> () - fn g _ = () - - ty main : fn -> int - fn main = f (g 2) 1", - ) - .unwrap(); - - let (_, expected) = toplevel( - "ty f : fn int -> int - fn f x = x - - ty g : fn int -> () - fn g _ = () - - ty main : fn -> int - fn main = let ___discarded = g 2 in f 1", - ) - .unwrap(); - assert_eq!(expected.len(), 6); - let expected = typecheck_toplevel(expected).unwrap(); - - let mut program = typecheck_toplevel(program).unwrap(); - run_toplevel(&mut program); - - assert_eq!(program, expected); - } -} |