From ea3b2df83d97fbeb4eac835dce151faf71764ca8 Mon Sep 17 00:00:00 2001
From: universalmind303 <cory.grinstead@gmail.com>
Date: Mon, 2 Oct 2023 22:54:30 -0500
Subject: [PATCH] chore: better list dtype formatting (#1840)
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closes #1769
before:
```
> select current_schemas();
┌────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ current_schemas                                                                                    │
│ ──                                                                                                 │
│ List(Field { name: "item", data_type: Utf8, nullable: true, dict_id: 0, dict_is_ordered: false, m… │
╞════════════════════════════════════════════════════════════════════════════════════════════════════╡
│ [public]                                                                                           │
└────────────────────────────────────────────────────────────────────────────────────────────────────┘
```

after:
```
> select current_schemas();
┌─────────────────┐
│ current_schemas │
│ ──              │
│ List[Utf8]      │
╞═════════════════╡
│ [public]        │
└─────────────────┘
```
---
 crates/arrow_util/src/pretty.rs | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/crates/arrow_util/src/pretty.rs b/crates/arrow_util/src/pretty.rs
index 80ca930f3..cab7a2a01 100644
--- a/crates/arrow_util/src/pretty.rs
+++ b/crates/arrow_util/src/pretty.rs
@@ -265,6 +265,23 @@ struct ColumnHeader {
     alignment: CellAlignment,
 }
 
+fn fmt_dtype(dtype: &DataType) -> String {
+    match dtype {
+        DataType::Timestamp(tu, tz) => {
+            format!("Timestamp[{}, {}]", fmt_timeunit(tu), fmt_timezone(tz))
+        }
+        DataType::List(fld) | DataType::LargeList(fld) => {
+            format!("List[{}]", fmt_dtype(fld.data_type()))
+        }
+        DataType::Struct(flds) => flds
+            .iter()
+            .map(|f| format!("{}: {}", f.name(), fmt_dtype(f.data_type())))
+            .collect::<Vec<_>>()
+            .join(", "),
+        dtype => format!("{}", dtype),
+    }
+}
+
 impl ColumnHeader {
     fn from_field(f: &Field) -> Self {
         let alignment = if f.data_type().is_numeric() {
@@ -275,12 +292,7 @@ impl ColumnHeader {
 
         ColumnHeader {
             name: f.name().clone(),
-            data_type: match f.data_type() {
-                DataType::Timestamp(tu, tz) => {
-                    format!("Timestamp[{}, {}]", fmt_timeunit(tu), fmt_timezone(tz))
-                }
-                dtype => format!("{}", dtype),
-            },
+            data_type: fmt_dtype(f.data_type()),
             alignment,
         }
     }