Very early proof-of-concept git branch completion

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

@@ -6,6 +6,7 @@ pub struct Expression {
     pub expr: Expr,
     pub span: Span,
     pub ty: Type,
+    pub custom_completion: Option<String>,
 }
 
 impl Expression {
@@ -14,6 +15,7 @@ impl Expression {
             expr: Expr::Garbage,
             span,
             ty: Type::Unknown,
+            custom_completion: None,
         }
     }
 

crates/nu-protocol/src/syntax_shape.rs

@@ -69,6 +69,9 @@ pub enum SyntaxShape {
 
     /// A general expression, eg `1 + 2` or `foo --bar`
     Expression,
+
+    /// A custom shape with custom completion logic
+    Custom(Box<SyntaxShape>, String),
 }
 
 impl SyntaxShape {
@@ -77,6 +80,7 @@ impl SyntaxShape {
             SyntaxShape::Any => Type::Unknown,
             SyntaxShape::Block(_) => Type::Block,
             SyntaxShape::CellPath => Type::Unknown,
+            SyntaxShape::Custom(custom, _) => custom.to_type(),
             SyntaxShape::Duration => Type::Duration,
             SyntaxShape::Expression => Type::Unknown,
             SyntaxShape::FilePath => Type::FilePath,