error and exit

Author: cyteon

lang/src/functions.rs

@@ -22,6 +22,8 @@ pub fn get_functions() -> Vec<BuiltinFn> {
         builtin("float", float),
         builtin("str", str),
         builtin("bool", bool),
+        builtin("exit", exit),
+        builtin("error", error),
     ]
 }
 
@@ -123,4 +125,25 @@ fn bool(args: Vec<Value>) -> Result<Value, String> {
     }
 
     Ok(Value::Bool(args[0].truthy()))
+}
+
+fn exit(args: Vec<Value>) -> Result<Value, String> {
+    if args.len() == 0 {
+        std::process::exit(0);
+    } else if args.len() == 1 {
+        match &args[0] {
+            Value::Int(i) => std::process::exit(*i as i32),
+            _ => return Err(format!("exit() argument must be an int, got {}", args[0].type_name())),
+        }
+    } else {
+        return Err(format!("exit() takes at most one argument ({} given)", args.len()));
+    }
+}
+
+fn error(args: Vec<Value>) -> Result<Value, String> {
+    if args.len() != 1 {
+        return Err(format!("error() takes exactly one argument ({} given)", args.len()));
+    }
+
+    Err(format!("{}", args[0]))
 }

lang/src/vm/vm.rs

@@ -240,7 +240,13 @@ impl VM {
 
                             match (func.func)(args) {
                                 Ok(result) => self.stack.push(result),
-                                Err(e) => return Err(self.runtime_error(format!("error calling {}(): {}", func.name, e), span)),
+                                Err(e) => {
+                                    if func.name == "error" && !e.contains("error() takes exactly one argument") {
+                                        return Err(self.runtime_error(format!("{}", e), span));
+                                    }
+
+                                    return Err(self.runtime_error(format!("error calling {}(): {}", func.name, e), span));
+                                }
                             }
                         }
 

lang/test

@@ -0,0 +1 @@
+error("hi");