From ff09c7964e14ca13846c29392a685f841edb9cd6 Mon Sep 17 00:00:00 2001
From: Jack Wright <56345+ayax79@users.noreply.github.com>
Date: Wed, 7 Aug 2024 04:36:08 -0700
Subject: [PATCH] `polars open` will now open a lazy frame by default (#13556)

# Description
When opening a dataframe the default operation will be to create a lazy
frame if possible. This works much better with large datasets and
supports hive format.

# User-Facing Changes
- `--lazy` is nolonger a valid option. `--eager` must be used to
explicitly open an eager dataframe.
---
 crates/nu_plugin_polars/src/dataframe/eager/open.rs | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/crates/nu_plugin_polars/src/dataframe/eager/open.rs b/crates/nu_plugin_polars/src/dataframe/eager/open.rs
index c02e33b5664..6c4246497cb 100644
--- a/crates/nu_plugin_polars/src/dataframe/eager/open.rs
+++ b/crates/nu_plugin_polars/src/dataframe/eager/open.rs
@@ -46,7 +46,7 @@ impl PluginCommand for OpenDataFrame {
     }
 
     fn usage(&self) -> &str {
-        "Opens CSV, JSON, JSON lines, arrow, avro, or parquet file to create dataframe."
+        "Opens CSV, JSON, JSON lines, arrow, avro, or parquet file to create dataframe. A lazy dataframe will be created by default, if supported."
     }
 
     fn signature(&self) -> Signature {
@@ -56,7 +56,7 @@ impl PluginCommand for OpenDataFrame {
                 SyntaxShape::Filepath,
                 "file path to load values from",
             )
-            .switch("lazy", "creates a lazy dataframe", Some('l'))
+            .switch("eager", "Open dataframe as an eager dataframe", None)
             .named(
                 "type",
                 SyntaxShape::String,
@@ -173,7 +173,7 @@ fn from_parquet(
     file_path: &Path,
     file_span: Span,
 ) -> Result<Value, ShellError> {
-    if call.has_flag("lazy")? {
+    if !call.has_flag("eager")? {
         let file: String = call.req(0)?;
         let args = ScanArgsParquet {
             n_rows: None,
@@ -275,7 +275,7 @@ fn from_ipc(
     file_path: &Path,
     file_span: Span,
 ) -> Result<Value, ShellError> {
-    if call.has_flag("lazy")? {
+    if !call.has_flag("eager")? {
         let file: String = call.req(0)?;
         let args = ScanArgsIpc {
             n_rows: None,
@@ -389,7 +389,7 @@ fn from_jsonl(
         .map(|schema| NuSchema::try_from(&schema))
         .transpose()?;
 
-    if call.has_flag("lazy")? {
+    if !call.has_flag("eager")? {
         let start_time = std::time::Instant::now();
 
         let df = LazyJsonLineReader::new(file_path)
@@ -473,7 +473,7 @@ fn from_csv(
         .map(|schema| NuSchema::try_from(&schema))
         .transpose()?;
 
-    if call.has_flag("lazy")? {
+    if !call.has_flag("eager")? {
         let csv_reader = LazyCsvReader::new(file_path);
 
         let csv_reader = match delimiter {