Start building out type inference.

src/compiler.rs

@@ -1,5 +1,5 @@
-use crate::backend::Backend;
 use crate::syntax::Program as Syntax;
+use crate::{backend::Backend, ir::TypeInferenceResult};
 use codespan_reporting::{
     diagnostic::Diagnostic,
     files::SimpleFiles,
@@ -99,8 +99,38 @@ impl Compiler {
             return Ok(None);
         }
 
-        // Now that we've validated it, turn it into IR.
-        let ir = syntax.type_infer();
+        // Now that we've validated it, let's do type inference, potentially turning
+        // into IR while we're at it.
+        let ir = match syntax.type_infer() {
+            TypeInferenceResult::Failure {
+                mut errors,
+                mut warnings,
+            } => {
+                let messages = errors
+                    .drain(..)
+                    .map(Into::into)
+                    .chain(warnings.drain(..).map(Into::into));
+
+                for message in messages {
+                    self.emit(message);
+                }
+
+                return Ok(None);
+            }
+
+            TypeInferenceResult::Success {
+                result,
+                mut warnings,
+            } => {
+                let messages = warnings.drain(..).map(Into::into);
+
+                for message in messages {
+                    self.emit(message);
+                }
+
+                result
+            }
+        };
 
         // Finally, send all this to Cranelift for conversion into an object file.
         let mut backend = Backend::object_file(Triple::host())?;