chore: continue checking even if AST-linking failed

crates/erg_compiler/link_ast.rs

@@ -9,7 +9,7 @@ use erg_parser::ast::{
     TypeSpec, AST,
 };
 
-use crate::error::{TyCheckError, TyCheckErrors};
+use crate::error::{Failable, TyCheckError, TyCheckErrors};
 
 /// Combine method definitions across multiple modules, specialized class contexts, etc.
 #[derive(Debug, Default)]
@@ -31,7 +31,7 @@ impl ASTLinker {
         }
     }
 
-    pub fn link(mut self, ast: AST, mode: &str) -> Result<AST, TyCheckErrors> {
+    pub fn link(mut self, ast: AST, mode: &str) -> Failable<AST> {
         log!(info "the AST-linking process has started.");
         let mut new = vec![];
         for chunk in ast.module.into_iter() {
@@ -111,7 +111,7 @@ impl ASTLinker {
         if self.errs.is_empty() {
             Ok(ast)
         } else {
-            Err(self.errs)
+            Err((ast, self.errs))
         }
     }
 

crates/erg_compiler/lower.rs

@@ -3770,11 +3770,13 @@ impl<A: ASTBuildable> GenericASTLowerer<A> {
     pub fn lower(&mut self, ast: AST, mode: &str) -> Result<CompleteArtifact, IncompleteArtifact> {
         log!(info "the AST lowering process has started.");
         log!(info "the type-checking process has started.");
-        let ast = ASTLinker::new(self.cfg.clone())
-            .link(ast, mode)
-            .map_err(|errs| {
-                IncompleteArtifact::new(None, errs, LowerWarnings::from(self.warns.take_all()))
-            })?;
+        let ast = match ASTLinker::new(self.cfg.clone()).link(ast, mode) {
+            Ok(ast) => ast,
+            Err((ast, errs)) => {
+                self.errs.extend(errs);
+                ast
+            }
+        };
         if mode == "declare" {
             let hir = self.declare_module(ast);
             if self.errs.is_empty() {