Added error handling

include/ast/ast_base.hpp

@@ -7,6 +7,7 @@
 
 #include "lexer.hpp"
 #include "util/text.hpp"
+#include "util/error.hpp"
 
 namespace fsh {
 
@@ -67,9 +68,29 @@ namespace fsh {
       private:
     };
 
-    class AstBuildError : public std::runtime_error {
+    class AstBuildError : public util::LazyError {
       public:
-        AstBuildError(std::string err) : std::runtime_error(err) {}
+        AstBuildError() {}
     };
 
+    class AstUnexpectedTypeError : public AstBuildError {
+      public:
+        AstUnexpectedTypeError(Lexer::TokenType type) : type(type){};
+      private:
+        Lexer::TokenType type;
+
+        std::string build_msg() const noexcept override {
+          return (std::string) "Unexpected " + util::tokens[type];
+        };
+    };
+
+    class AstNoRedirectError : public AstBuildError {
+      private:
+        std::string build_msg() const noexcept override {
+          return "No redirects provided";
+        };
+    };
+
+
+
 }