1 files changed, 17 insertions, 12 deletions

diff --git a/main.cpp b/main.cpp
index f2c0b1d..a632c9b 100644
--- a/main.cpp
+++ b/main.cpp
@@ -40,14 +40,13 @@ int main()
     Var::pushScope();
 
     std::string line;
-    while (std::cin.good()) {
+    for (unsigned lineno = 1; std::cin.good(); ++lineno) {
         std::getline(std::cin, line);
-        parseString(line);
-        //std::cout << std::endl;
+        if (!parseString(line))
+            std::cerr << "    at line " << lineno << std::endl;
     }
 
     llvmState.output();
-
     std::cout << std::endl;
 }
 
@@ -56,11 +55,9 @@ bool parseString(std::string_view sv)
     do {
         const auto [nsv, tok] = nextToken(sv);
 
-        //printToken(tok);
-
         if (tok == Token::none && !nsv.empty()) {
-            std::cerr << "unknown " << nsv << std::endl;
-            break;
+            std::cerr << "error: unknown term: " << nsv << std::endl;
+            return false;
         } else {
             std::unique_ptr<BaseAST> expr;
 
@@ -76,6 +73,8 @@ bool parseString(std::string_view sv)
                 {
                 auto& thunk = scope.back();
                 auto gen = thunk.codegen(llvmState);
+                if (!gen)
+                    return false;
                 Var::popScope();
                 Var::addLocal(thunk.name, Var {gen, true});
                 expr.reset(new PushAST {thunk.name});
@@ -83,7 +82,8 @@ bool parseString(std::string_view sv)
                 }
                 break;
             case Token::Quote:
-                break;
+                std::cerr << "error: quoting is not supported!" << std::endl;
+                return false;
             case Token::PopVar:
                 expr.reset(new PopAST {name});
                 break;
@@ -100,9 +100,14 @@ bool parseString(std::string_view sv)
                 break;
             }
 
-            if (expr && !scope.empty()) {
-                expr->codegen(llvmState);
-                //scope.back().body.emplace_back().swap(expr);
+            if (expr) {
+                if (!scope.empty()) {
+                    if (!expr->codegen(llvmState))
+                        return false;
+                } else if (tok != Token::ThunkClose) {
+                    std::cerr << "error: non-thunk at top level!" << std::endl;
+                    return false;
+                }
             }
         }