refactor(error_display): generic display method for error types

this is to better support ariadne in the future

src/error_display.rs

@@ -0,0 +1,26 @@
+use crate::{
+    command::CommandParseError, meta_commands::MetaCommandParseError,
+    statements::StatementParseError,
+};
+
+pub trait OSDBError {
+    fn display(&self);
+}
+
+impl OSDBError for MetaCommandParseError {
+    fn display(&self) {
+        println!("{self}")
+    }
+}
+
+impl OSDBError for StatementParseError {
+    fn display(&self) {
+        println!("{self}")
+    }
+}
+
+impl OSDBError for CommandParseError {
+    fn display(&self) {
+        println!("{self}")
+    }
+}

src/lib.rs

@@ -1,6 +1,7 @@
 pub mod branding;
 pub mod cli;
 pub mod command;
+pub mod error_display;
 pub mod meta_commands;
 pub mod statements;
 pub mod tokens;

src/main.rs

@@ -1,6 +1,7 @@
 use osdb::branding::startup_msg;
 use osdb::cli::read_input;
 use osdb::command::Command;
+use osdb::error_display::OSDBError as _;
 
 fn main() {
     startup_msg();
@@ -12,7 +13,7 @@ fn main() {
                     break;
                 }
             }
-            Err(err) => eprintln!("{err}"),
+            Err(err) => err.display(),
         }
     }
 }