From 8136170431bed4f3da6f1982591a50ae353b7103 Mon Sep 17 00:00:00 2001
From: WindSoilder <WindSoilder@outlook.com>
Date: Tue, 14 Feb 2023 00:35:53 +0800
Subject: [PATCH] support multiplication operation on string and list values
 (#8061)
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# Description

As title, I found this feature is useful to me too :)

Closes: #8039

# User-Facing Changes

```
❯ 3 * "ab"
ababab

❯ 3 * [1 2 3]
╭───┬───╮
│ 0 │ 1 │
│ 1 │ 2 │
│ 2 │ 3 │
│ 3 │ 1 │
│ 4 │ 2 │
│ 5 │ 3 │
│ 6 │ 1 │
│ 7 │ 2 │
│ 8 │ 3 │
╰───┴───╯
```

# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
---
 crates/nu-command/tests/commands/math/mod.rs | 28 +++++++++++++++++++
 crates/nu-parser/src/type_check.rs           |  4 +++
 crates/nu-protocol/src/value/mod.rs          | 29 +++++++++++++++++++-
 3 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/crates/nu-command/tests/commands/math/mod.rs b/crates/nu-command/tests/commands/math/mod.rs
index e8fc3ae106..fd03b7109d 100644
--- a/crates/nu-command/tests/commands/math/mod.rs
+++ b/crates/nu-command/tests/commands/math/mod.rs
@@ -543,3 +543,31 @@ fn append_binary_values() {
     ));
     assert_eq!(actual.out, "0x[01020304]");
 }
+
+#[test]
+fn int_multiple_string() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"3 * "ab""#
+    ));
+    assert_eq!(actual.out, "ababab");
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#""ab" * 3"#
+    ));
+    assert_eq!(actual.out, "ababab");
+}
+
+#[test]
+fn int_multiple_list() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"3 * [1 2] | to nuon"#
+    ));
+    assert_eq!(actual.out, "[1, 2, 1, 2, 1, 2]");
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"[1 2] * 3 | to nuon"#
+    ));
+    assert_eq!(actual.out, "[1, 2, 1, 2, 1, 2]");
+}
diff --git a/crates/nu-parser/src/type_check.rs b/crates/nu-parser/src/type_check.rs
index 93e9dbde71..2d5ef6fbad 100644
--- a/crates/nu-parser/src/type_check.rs
+++ b/crates/nu-parser/src/type_check.rs
@@ -142,6 +142,10 @@ pub fn math_result_type(
                 (Type::Int, Type::Duration) => (Type::Duration, None),
                 (Type::Duration, Type::Float) => (Type::Duration, None),
                 (Type::Float, Type::Duration) => (Type::Duration, None),
+                (Type::Int, Type::String) => (Type::String, None),
+                (Type::String, Type::Int) => (Type::String, None),
+                (Type::Int, Type::List(a)) => (Type::List(a.clone()), None),
+                (Type::List(a), Type::Int) => (Type::List(a.clone()), None),
 
                 (Type::Custom(a), Type::Custom(b)) if a == b => (Type::Custom(a.to_string()), None),
                 (Type::Custom(a), _) => (Type::Custom(a.to_string()), None),
diff --git a/crates/nu-protocol/src/value/mod.rs b/crates/nu-protocol/src/value/mod.rs
index 300c2c16b2..d39be76daf 100644
--- a/crates/nu-protocol/src/value/mod.rs
+++ b/crates/nu-protocol/src/value/mod.rs
@@ -2264,7 +2264,34 @@ impl Value {
             (Value::CustomValue { val: lhs, span }, rhs) => {
                 lhs.operation(*span, Operator::Math(Math::Multiply), op, rhs)
             }
-
+            (Value::Int { val: lhs, .. }, Value::String { val: rhs, .. }) => {
+                let mut res = String::new();
+                for _ in 0..*lhs {
+                    res.push_str(rhs)
+                }
+                Ok(Value::String { val: res, span })
+            }
+            (Value::String { val: lhs, .. }, Value::Int { val: rhs, .. }) => {
+                let mut res = String::new();
+                for _ in 0..*rhs {
+                    res.push_str(lhs)
+                }
+                Ok(Value::String { val: res, span })
+            }
+            (Value::Int { val: lhs, .. }, Value::List { vals: rhs, .. }) => {
+                let mut res = vec![];
+                for _ in 0..*lhs {
+                    res.append(&mut rhs.clone())
+                }
+                Ok(Value::List { vals: res, span })
+            }
+            (Value::List { vals: lhs, .. }, Value::Int { val: rhs, .. }) => {
+                let mut res = vec![];
+                for _ in 0..*rhs {
+                    res.append(&mut lhs.clone())
+                }
+                Ok(Value::List { vals: res, span })
+            }
             _ => Err(ShellError::OperatorMismatch {
                 op_span: op,
                 lhs_ty: self.get_type(),