Start parsing 'use'; Add Use command

crates/nu-command/src/default_context.rs

@@ -7,7 +7,7 @@ use nu_protocol::{
 
 use crate::{
     where_::Where, Alias, Benchmark, BuildString, Def, Do, Each, External, For, Git, GitCheckout,
-    If, Length, Let, LetEnv, Lines, ListGitBranches, Ls, Module, Table,
+    If, Length, Let, LetEnv, Lines, ListGitBranches, Ls, Module, Table, Use,
 };
 
 pub fn create_default_context() -> Rc<RefCell<EngineState>> {
@@ -48,6 +48,8 @@ pub fn create_default_context() -> Rc<RefCell<EngineState>> {
 
         working_set.add_decl(Box::new(Module));
 
+        working_set.add_decl(Box::new(Use));
+
         working_set.add_decl(Box::new(Table));
 
         working_set.add_decl(Box::new(External));

crates/nu-command/src/lib.rs

@@ -18,6 +18,7 @@ mod ls;
 mod module;
 mod run_external;
 mod table;
+mod use_;
 mod where_;
 
 pub use alias::Alias;
@@ -40,3 +41,4 @@ pub use ls::Ls;
 pub use module::Module;
 pub use run_external::External;
 pub use table::Table;
+pub use use_::Use;

crates/nu-command/src/use_.rs

@@ -0,0 +1,29 @@
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EvaluationContext};
+use nu_protocol::{Signature, SyntaxShape, Value};
+
+pub struct Use;
+
+impl Command for Use {
+    fn name(&self) -> &str {
+        "use"
+    }
+
+    fn usage(&self) -> &str {
+        "Use definitions from a module"
+    }
+
+    fn signature(&self) -> nu_protocol::Signature {
+        Signature::build("use")
+            .required("module_name", SyntaxShape::String, "module name")
+    }
+
+    fn run(
+        &self,
+        _context: &EvaluationContext,
+        call: &Call,
+        _input: Value,
+    ) -> Result<nu_protocol::Value, nu_protocol::ShellError> {
+        Ok(Value::Nothing { span: call.head })
+    }
+}