summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorDavid Li <li.davidm96@gmail.com>2017-11-05 09:27:10 -0500
committerDavid Li <li.davidm96@gmail.com>2017-11-05 09:27:10 -0500
commitb0711ef63501b7c29cb7c2014f3ceeaa399e3481 (patch)
treeeb1cf61610517a7479e3f78a30b4bff37dd44708
parent9f393b2eb7b3fb8f1924e80095bad3384049cc67 (diff)
Add stubbed out type checker
-rw-r--r--src/ast.rs18
-rw-r--r--src/main.rs7
-rw-r--r--src/semantic/environment.rs33
-rw-r--r--src/semantic/mod.rs3
-rw-r--r--src/semantic/translate.rs39
-rw-r--r--src/semantic/types.rs7
6 files changed, 99 insertions, 8 deletions
diff --git a/src/ast.rs b/src/ast.rs
index 7edf9c7..c3925b0 100644
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -1,32 +1,36 @@
#[derive(Debug)]
pub struct WithLocation<T> {
- value: T,
- location: (usize, usize),
+ pub value: T,
+ pub start: usize,
+ pub end: usize,
}
impl<T> WithLocation<T> {
pub fn new(value: T, start: usize, end: usize) -> WithLocation<T> {
WithLocation {
value: value,
- location: (start, end),
+ start: start,
+ end: end,
}
}
pub fn map<U, F: FnOnce(T) -> U>(self, f: F) -> WithLocation<U> {
WithLocation {
value: f(self.value),
- location: self.location,
+ start: self.start,
+ end: self.end,
}
}
pub fn join_map<U, V, F>(self, other: WithLocation<U>, f: F) -> WithLocation<V>
where F: FnOnce(WithLocation<T>, WithLocation<U>) -> V
{
- let loc1 = self.location;
- let loc2 = other.location;
+ let start = self.start;
+ let end = other.end;
WithLocation {
value: f(self, other),
- location: (loc1.0, loc2.1),
+ start: start,
+ end: end,
}
}
}
diff --git a/src/main.rs b/src/main.rs
index 8976597..8264f97 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,5 @@
pub mod ast;
+pub mod semantic;
pub mod taiga;
use std::io::{self, BufRead, Write};
@@ -12,7 +13,11 @@ fn main() {
io::stdout().flush().unwrap();
if let Ok(n) = handle.read_line(&mut input) {
if n == 0 { break; }
- println!("{:?}", taiga::parse_Program(&input));
+ let program = taiga::parse_Program(&input);
+ println!("{:?}", program);
+ if let Ok(program) = program {
+ println!("{:?}", semantic::translate::translate(&program));
+ }
}
else {
break;
diff --git a/src/semantic/environment.rs b/src/semantic/environment.rs
new file mode 100644
index 0000000..fab16b3
--- /dev/null
+++ b/src/semantic/environment.rs
@@ -0,0 +1,33 @@
+use std::collections::HashMap;
+use std::hash::Hash;
+
+pub struct Environment<'a, T: 'a, U: 'a> {
+ pub parent: Option<&'a Environment<'a, T, U>>,
+ pub bindings: HashMap<T, U>,
+}
+
+impl<'a, T: 'a, U: 'a> Environment<'a, T, U>
+ where T: Eq + Hash {
+ pub fn new(parent: Option<&'a Environment<'a, T, U>>) -> Environment<'a, T, U> {
+ Environment {
+ parent: parent,
+ bindings: HashMap::new(),
+ }
+ }
+
+ pub fn add_binding(&mut self, key: T, value: U) {
+ self.bindings.insert(key, value);
+ }
+
+ pub fn lookup(&self, key: &T) -> Option<&U> {
+ if let Some(v) = self.bindings.get(key) {
+ Some(v)
+ }
+ else if let Some(p) = self.parent {
+ p.lookup(key)
+ }
+ else {
+ None
+ }
+ }
+}
diff --git a/src/semantic/mod.rs b/src/semantic/mod.rs
new file mode 100644
index 0000000..433a196
--- /dev/null
+++ b/src/semantic/mod.rs
@@ -0,0 +1,3 @@
+pub mod environment;
+pub mod translate;
+pub mod types;
diff --git a/src/semantic/translate.rs b/src/semantic/translate.rs
new file mode 100644
index 0000000..7bcd646
--- /dev/null
+++ b/src/semantic/translate.rs
@@ -0,0 +1,39 @@
+use ::ast::{self, WithLocation};
+use super::environment;
+use super::types::Ty;
+
+#[derive(Debug)]
+pub enum TypeError {
+ Unimplemented,
+}
+
+type TypeEnvironment<'a> = environment::Environment<'a, String, Ty>;
+pub type Result = ::std::result::Result<Ty, WithLocation<TypeError>>;
+
+pub fn translate(program: &ast::Program) -> Result {
+ trans_exp(TypeEnvironment::new(None), &*program.0)
+}
+
+fn trans_exp<'a>(venv: TypeEnvironment<'a>, exp: &WithLocation<ast::Expression>) -> Result {
+ use ast::Expression::*;
+
+ match &exp.value {
+ &Let(ref decls, ref body) => {
+ Err(WithLocation::new(TypeError::Unimplemented, exp.start, exp.end))
+ },
+ &UnaryOp(ref op, ref operand) => {
+ Err(WithLocation::new(TypeError::Unimplemented, exp.start, exp.end))
+ },
+ &BinOp(ref op, ref left, ref right) => {
+ Err(WithLocation::new(TypeError::Unimplemented, exp.start, exp.end))
+ },
+ &Number(_) => Ok(Ty::Int),
+ &String(_) => Ok(Ty::String),
+ &Name(ref name) => {
+ Err(WithLocation::new(TypeError::Unimplemented, exp.start, exp.end))
+ },
+ &Nil => {
+ Err(WithLocation::new(TypeError::Unimplemented, exp.start, exp.end))
+ },
+ }
+}
diff --git a/src/semantic/types.rs b/src/semantic/types.rs
new file mode 100644
index 0000000..2d76387
--- /dev/null
+++ b/src/semantic/types.rs
@@ -0,0 +1,7 @@
+#[derive(Debug)]
+pub enum Ty {
+ Int,
+ String,
+ Nil,
+ Unit,
+}