Add the start of a hindley-milner typechecker

The beginning of a parse-don't-validate-based hindley-milner
typechecker, which returns on success an IR where every AST node
trivially knows its own type, and using those types to determine LLVM
types in codegen.

1 files changed, 10 insertions, 1 deletions

diff --git a/src/common/error.rs b/src/common/error.rs
index f3f3023ceaf8..51575a895e91 100644
--- a/src/common/error.rs
+++ b/src/common/error.rs
@@ -2,7 +2,7 @@ use std::{io, result};
 
 use thiserror::Error;
 
-use crate::{codegen, interpreter, parser};
+use crate::{codegen, interpreter, parser, tc};
 
 #[derive(Error, Debug)]
 pub enum Error {
@@ -18,6 +18,9 @@ pub enum Error {
     #[error("Compile error: {0}")]
     CodegenError(#[from] codegen::Error),
 
+    #[error("Type error: {0}")]
+    TypeError(#[from] tc::Error),
+
     #[error("{0}")]
     Message(String),
 }
@@ -28,6 +31,12 @@ impl From<String> for Error {
     }
 }
 
+impl<'a> From<&'a str> for Error {
+    fn from(s: &'a str) -> Self {
+        Self::Message(s.to_owned())
+    }
+}
+
 impl<'a> From<nom::Err<nom::error::Error<&'a str>>> for Error {
     fn from(e: nom::Err<nom::error::Error<&'a str>>) -> Self {
         use nom::error::Error as NomError;