From 0108a935ed50f4599a3dc537565d55acdc9a053c Mon Sep 17 00:00:00 2001
From: JT <jonathan.d.turner@gmail.com>
Date: Mon, 27 Sep 2021 13:23:22 +1300
Subject: [PATCH] add import lists

---
 crates/nu-parser/src/parse_keywords.rs       | 18 +++++++++++
 crates/nu-parser/src/parser.rs               | 34 +++++++++++++++++++-
 crates/nu-protocol/src/ast/import_pattern.rs |  1 +
 src/tests.rs                                 |  8 +++++
 4 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/crates/nu-parser/src/parse_keywords.rs b/crates/nu-parser/src/parse_keywords.rs
index e7bcb38a3b..1908233d19 100644
--- a/crates/nu-parser/src/parse_keywords.rs
+++ b/crates/nu-parser/src/parse_keywords.rs
@@ -397,6 +397,24 @@ pub fn parse_use(
 
                     new_exports
                 }
+                ImportPatternMember::List { names } => {
+                    let mut output = vec![];
+
+                    for (name, span) in names {
+                        let mut new_exports: Vec<(Vec<u8>, usize)> = exports
+                            .iter()
+                            .filter_map(|x| if &x.0 == name { Some(x.clone()) } else { None })
+                            .collect();
+
+                        if new_exports.is_empty() {
+                            error = error.or(Some(ParseError::ExportNotFound(*span)))
+                        } else {
+                            output.append(&mut new_exports)
+                        }
+                    }
+
+                    output
+                }
             }
         };
 
diff --git a/crates/nu-parser/src/parser.rs b/crates/nu-parser/src/parser.rs
index a794b1a292..59508cdfe2 100644
--- a/crates/nu-parser/src/parser.rs
+++ b/crates/nu-parser/src/parser.rs
@@ -1376,7 +1376,7 @@ pub fn parse_type(_working_set: &StateWorkingSet, bytes: &[u8]) -> Type {
 }
 
 pub fn parse_import_pattern(
-    working_set: &StateWorkingSet,
+    working_set: &mut StateWorkingSet,
     span: Span,
 ) -> (ImportPattern, Option<ParseError>) {
     let source = working_set.get_span_contents(span);
@@ -1409,6 +1409,38 @@ pub fn parse_import_pattern(
                 },
                 error,
             )
+        } else if tail.starts_with(b"[") {
+            let (result, err) = parse_list_expression(working_set, tail_span, &SyntaxShape::String);
+            error = error.or(err);
+
+            let mut output = vec![];
+
+            match result {
+                Expression {
+                    expr: Expr::List(list),
+                    ..
+                } => {
+                    for l in list {
+                        let contents = working_set.get_span_contents(l.span);
+                        output.push((contents.to_vec(), l.span));
+                    }
+
+                    (
+                        ImportPattern {
+                            head,
+                            members: vec![ImportPatternMember::List { names: output }],
+                        },
+                        error,
+                    )
+                }
+                _ => (
+                    ImportPattern {
+                        head,
+                        members: vec![],
+                    },
+                    Some(ParseError::ExportNotFound(result.span)),
+                ),
+            }
         } else {
             (
                 ImportPattern {
diff --git a/crates/nu-protocol/src/ast/import_pattern.rs b/crates/nu-protocol/src/ast/import_pattern.rs
index c5183d75eb..1b7d6ad0fd 100644
--- a/crates/nu-protocol/src/ast/import_pattern.rs
+++ b/crates/nu-protocol/src/ast/import_pattern.rs
@@ -4,6 +4,7 @@ use crate::Span;
 pub enum ImportPatternMember {
     Glob { span: Span },
     Name { name: Vec<u8>, span: Span },
+    List { names: Vec<(Vec<u8>, Span)> },
 }
 
 #[derive(Debug, Clone)]
diff --git a/src/tests.rs b/src/tests.rs
index c95d8e6156..22b33e6323 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -374,3 +374,11 @@ fn module_imports_4() -> TestResult {
         "not find import",
     )
 }
+
+#[test]
+fn module_imports_5() -> TestResult {
+    run_test(
+        r#"module foo { def a [] { 1 }; def b [] { 2 }; def c [] { 3 } }; use foo.[a, c]; c"#,
+        "3",
+    )
+}