From 990d4f0f76992503600384586a0571a1e3915b65 Mon Sep 17 00:00:00 2001
From: Per Lindgren <per.lindgren@ltu.se>
Date: Fri, 18 Sep 2020 15:24:45 +0200
Subject: [PATCH] all tests pass
---
examples/mut.rs | 4 +--
examples/mut2.rs | 4 +--
src/check.rs | 61 ++++++++++++++++++++++++++++++++++++++-------
tests/test_check.rs | 15 +++++++++++
tests/test_vm.rs | 4 +++
5 files changed, 75 insertions(+), 13 deletions(-)
diff --git a/examples/mut.rs b/examples/mut.rs
index a93ad51..ec2e140 100644
--- a/examples/mut.rs
+++ b/examples/mut.rs
@@ -1,5 +1,5 @@
-fn main() -> i32 {
+fn main() {
let mut a = 0;
a = 2;
- a
+ let b = a;
}
diff --git a/examples/mut2.rs b/examples/mut2.rs
index 2166959..33fd4af 100644
--- a/examples/mut2.rs
+++ b/examples/mut2.rs
@@ -1,8 +1,8 @@
-fn main() -> i32 {
+fn main() {
let mut a = 0;
a = 2;
let mut b = a; // copy semantics
a = 3;
b = b + 1;
- a + b
+ let c = a + b;
}
diff --git a/src/check.rs b/src/check.rs
index 1b16944..18d5675 100644
--- a/src/check.rs
+++ b/src/check.rs
@@ -190,6 +190,41 @@ fn expr_type(
}
}
+fn lexpr_type<'a>(
+ e: &Expr,
+ fn_env: &FnEnv,
+ type_env: &TypeEnv,
+ var_env: &'a mut VarEnv,
+) -> Result<&'a mut Type, Error> {
+ use Expr::*;
+ trace!("expr_type {}", e);
+ trace!("var_env {:?}", var_env);
+
+ match e {
+ Id(id) => match var_env.get_mut(id.to_string()) {
+ Some(t) => Ok(t),
+ None => Err(format!("variable not found {}", id)),
+ },
+
+ DeRef(deref_e) => {
+ let t = lexpr_type(deref_e, fn_env, type_env, var_env)?;
+ trace!("deref_t {}", &t);
+
+ // strip mut
+ let t = match t {
+ Type::Mut(t) => t,
+ _ => t,
+ };
+ trace!("strip deref_t {}", t);
+ match t {
+ Type::Ref(dt) => Ok(dt),
+ _ => Err(format!("cannot deref {} of type {}", e, t)),
+ }
+ }
+ _ => Err(format!("Illegal left hand expression {}", e)),
+ }
+}
+
fn strip_mut(t: Type) -> Type {
match t {
Type::Mut(t) => *t,
@@ -228,7 +263,8 @@ pub fn check_stmts(
let t: Type = match (ot, oe) {
(Some(t), Some(e)) => {
let e_type = expr_type(&*e, fn_env, type_env, var_env)?;
- match *t == e_type {
+ let e_type = strip_mut(e_type);
+ match strip_mut(t.clone()) == e_type {
true => t.clone(),
false => {
trace!("e {}", e);
@@ -237,9 +273,9 @@ pub fn check_stmts(
}
}
(None, Some(e)) => {
- let et = expr_type(&*e, fn_env, type_env, var_env)?;
- match is_known(&et) {
- true => et,
+ let e_type = strip_mut(expr_type(&*e, fn_env, type_env, var_env)?);
+ match is_known(&e_type) {
+ true => e_type,
_ => Err("reference to unknown type".to_string())?,
}
}
@@ -256,21 +292,28 @@ pub fn check_stmts(
}
Assign(lh, e) => {
+ trace!("assign");
+
let e_type = expr_type(&*e, fn_env, type_env, var_env)?;
- trace!("e_type = {}", e_type);
- trace!("lh = {:?}", lh);
+ trace!("e_type = {}", &e_type);
+ let e_type = strip_mut(e_type);
+ trace!("e_type stripped = {}", &e_type);
+
+ trace!("lh expr = {:?}", lh);
- let lh_type = expr_type(lh, fn_env, type_env, var_env)?;
- trace!("lh_type {}", &lh_type);
+ let lh_type = lexpr_type(lh, fn_env, type_env, var_env)?;
+ trace!("lh_type {}", lh_type);
- if match &lh_type {
+ if match lh_type {
Type::Unknown => {
trace!("assign to unknown");
+ *lh_type = e_type.clone();
true
}
Type::Mut(t) => match **t {
Type::Unknown => {
trace!("assign to `mut Unknown`");
+ *t = Box::new(e_type.clone());
true
}
_ => **t == e_type,
diff --git a/tests/test_check.rs b/tests/test_check.rs
index d120948..6334148 100644
--- a/tests/test_check.rs
+++ b/tests/test_check.rs
@@ -21,6 +21,11 @@ fn check_assign2() {
assert!(check(&read_file::parse("examples/assign2.rs")).is_ok());
}
+#[test]
+fn check_assign3() {
+ assert!(check(&read_file::parse("examples/assign3.rs")).is_ok());
+}
+
#[test]
fn check_assign_err() {
assert!(check(&read_file::parse("examples/assign_err.rs")).is_err());
@@ -154,3 +159,13 @@ fn check_ref_err3() {
fn check_ref_err4() {
assert!(check(&read_file::parse("examples/ref_err4.rs")).is_err());
}
+
+#[test]
+fn check_scopes() {
+ assert!(check(&read_file::parse("examples/scopes.rs")).is_ok());
+}
+
+#[test]
+fn check_scopes_err() {
+ assert!(check(&read_file::parse("examples/scopes_err.rs")).is_err());
+}
diff --git a/tests/test_vm.rs b/tests/test_vm.rs
index 27086b6..33d7729 100644
--- a/tests/test_vm.rs
+++ b/tests/test_vm.rs
@@ -35,6 +35,10 @@ fn scopes_test() {
eval_prog("examples/scopes.rs");
}
+#[test]
+fn scopes_err_test() {
+ eval_prog("examples/scopes_err.rs");
+}
#[test]
fn vm_test() {
eval_prog("examples/vm.rs");
--
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