feat(meta): version command

grammar.ebnf

@@ -10,6 +10,7 @@ select       ::= "select"
 
 meta-command ::= "." "exit"
                    | "about"
+                   | "version"
 
 int          ::= sign? digit+
 sign         ::= "+"

notes.org

@@ -226,8 +226,8 @@ i will use rustyline, since it seems like the most feature-complete
 
 * DONE write a proper grammar
 
-* TODO .about meta-command
-* TODO .version meta-command
+* DONE .about meta-command
+* DONE .version meta-command
 * TODO .license meta-command
 * TODO .help meta-command
 

src/branding.rs

@@ -13,12 +13,18 @@ pub fn startup_msg() -> String {
     )
 }
 
-pub fn about_msg() -> String {
+pub fn version_msg() -> String {
     let name = env!("CARGO_PKG_NAME");
     let version = env!("CARGO_PKG_VERSION");
 
+    format!("{name} v{version}")
+}
+
+pub fn about_msg() -> String {
+    let version = version_msg();
+
     format!(
-        "{name} v{version} -- A database engine\n\
+        "{version} -- A database engine\n\
         Note: This is experimental software. No maintenance is intendend."
     )
 }

src/meta_commands.rs

@@ -4,6 +4,7 @@ use crate::branding;
 pub enum MetaCommand {
     Exit,
     About,
+    Version,
 }
 
 impl std::fmt::Display for MetaCommand {
@@ -11,6 +12,7 @@ impl std::fmt::Display for MetaCommand {
         match self {
             MetaCommand::Exit => write!(f, "exit"),
             MetaCommand::About => write!(f, "about"),
+            MetaCommand::Version => write!(f, "version"),
         }
     }
 }
@@ -24,9 +26,13 @@ impl MetaCommand {
         match self {
             MetaCommand::Exit => MetaCommandExecuteResult { should_exit: true },
             MetaCommand::About => {
-                print!("{}", branding::about_msg());
-                MetaCommandExecuteResult { should_exit: false }
-            }
+                        print!("{}", branding::about_msg());
+                        MetaCommandExecuteResult { should_exit: false }
+                    }
+            MetaCommand::Version => {
+                print!("{}", branding::version_msg());
+                        MetaCommandExecuteResult { should_exit: false }
+            },
         }
     }
 }

src/tokens.rs

@@ -161,6 +161,7 @@ impl Tokenizer {
         match word.to_lowercase().as_str() {
             ".exit" => Some(TokenData::MetaCommand(MetaCommand::Exit)),
             ".about" => Some(TokenData::MetaCommand(MetaCommand::About)),
+            ".version" => Some(TokenData::MetaCommand(MetaCommand::Version)),
             _ => None,
         }
     }