Add wrap and get and cell_path parsing

crates/nu-protocol/src/ast/call.rs

@@ -45,4 +45,8 @@ impl Call {
 
         None
     }
+
+    pub fn nth(&self, pos: usize) -> Option<Expression> {
+        self.positional.get(pos).cloned()
+    }
 }

crates/nu-protocol/src/ast/cell_path.rs

@@ -1,13 +1,14 @@
 use super::Expression;
 use crate::Span;
+use serde::{Deserialize, Serialize};
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub enum PathMember {
     String { val: String, span: Span },
     Int { val: usize, span: Span },
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct CellPath {
     pub members: Vec<PathMember>,
 }

crates/nu-protocol/src/ast/expr.rs

@@ -1,4 +1,4 @@
-use super::{Call, Expression, FullCellPath, Operator, RangeOperator};
+use super::{Call, CellPath, Expression, FullCellPath, Operator, RangeOperator};
 use crate::{BlockId, Signature, Span, VarId};
 
 #[derive(Debug, Clone)]
@@ -24,6 +24,7 @@ pub enum Expr {
     Table(Vec<Expression>, Vec<Vec<Expression>>),
     Keyword(Vec<u8>, Span, Box<Expression>),
     String(String), // FIXME: improve this in the future?
+    CellPath(CellPath),
     FullCellPath(Box<FullCellPath>),
     Signature(Box<Signature>),
     Garbage,

crates/nu-protocol/src/value/mod.rs

@@ -9,7 +9,7 @@ pub use stream::*;
 
 use std::fmt::Debug;
 
-use crate::ast::PathMember;
+use crate::ast::{CellPath, PathMember};
 use crate::{span, BlockId, Span, Type};
 
 use crate::ShellError;
@@ -72,6 +72,10 @@ pub enum Value {
         val: Vec<u8>,
         span: Span,
     },
+    CellPath {
+        val: CellPath,
+        span: Span,
+    },
 }
 
 impl Value {
@@ -99,6 +103,7 @@ impl Value {
             Value::Stream { span, .. } => *span,
             Value::Nothing { span, .. } => *span,
             Value::Binary { span, .. } => *span,
+            Value::CellPath { span, .. } => *span,
         }
     }
 
@@ -119,6 +124,7 @@ impl Value {
             Value::Nothing { span, .. } => *span = new_span,
             Value::Error { .. } => {}
             Value::Binary { span, .. } => *span = new_span,
+            Value::CellPath { span, .. } => *span = new_span,
         }
 
         self
@@ -143,6 +149,7 @@ impl Value {
             Value::Stream { .. } => Type::ValueStream,
             Value::Error { .. } => Type::Error,
             Value::Binary { .. } => Type::Binary,
+            Value::CellPath { .. } => Type::CellPath,
         }
     }
 
@@ -184,6 +191,7 @@ impl Value {
             Value::Nothing { .. } => String::new(),
             Value::Error { error } => format!("{:?}", error),
             Value::Binary { val, .. } => format!("{:?}", val),
+            Value::CellPath { val, .. } => format!("{:?}", val),
         }
     }
 
@@ -215,6 +223,7 @@ impl Value {
             Value::Nothing { .. } => String::new(),
             Value::Error { error } => format!("{:?}", error),
             Value::Binary { val, .. } => format!("{:?}", val),
+            Value::CellPath { val, .. } => format!("{:?}", val),
         }
     }