From d3d2f67fbf8765b326778f19c2866bac386a74b9 Mon Sep 17 00:00:00 2001
From: Alex Gaynor <alexander.n.gaynor@omb.eop.gov>
Date: Wed, 8 Jan 2025 13:02:43 -0500
Subject: [PATCH] Refactor the lifetimes for more flexibility

---
 src/lib.rs    |  2 +-
 src/loader.rs | 35 +++++++++++++++++++++++++++++------
 src/main.rs   |  4 +++-
 3 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index e21ac8cb..070b4ce7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,3 @@
 pub mod loader;
 
-pub use crate::loader::{CsvLoader, ExactSizeIterable, Loader};
+pub use crate::loader::{CsvLoader, Loader, Record};
diff --git a/src/loader.rs b/src/loader.rs
index 62c7a791..e48acd2f 100644
--- a/src/loader.rs
+++ b/src/loader.rs
@@ -1,18 +1,41 @@
 use std::fs::File;
-use std::iter;
 
-pub trait ExactSizeIterable {
-    fn iter(&self) -> impl iter::ExactSizeIterator<Item = &[u8]>;
+pub trait AsRef<'a, T>
+where
+    T: ?Sized,
+{
+    fn as_ref(&self) -> &'a T;
 }
 
-impl ExactSizeIterable for csv::ByteRecord {
-    fn iter(&self) -> impl iter::ExactSizeIterator<Item = &[u8]> {
+impl<'a> AsRef<'a, [u8]> for &'a [u8] {
+    fn as_ref(&self) -> &'a [u8] {
+        self
+    }
+}
+
+pub trait Record {
+    type Item<'a>: AsRef<'a, [u8]>
+    where
+        Self: 'a;
+
+    type Iter<'a>: ExactSizeIterator<Item = Self::Item<'a>>
+    where
+        Self: 'a;
+
+    fn iter(&self) -> Self::Iter<'_>;
+}
+
+impl Record for csv::ByteRecord {
+    type Item<'a> = &'a [u8];
+    type Iter<'a> = csv::ByteRecordIter<'a>;
+
+    fn iter(&self) -> Self::Iter<'_> {
         self.into_iter()
     }
 }
 
 pub trait Loader {
-    type RecordType: ExactSizeIterable;
+    type RecordType: Record;
 
     /// Name of the resource we're loading from (e.g., a file path).
     fn name(&self) -> &str;
diff --git a/src/main.rs b/src/main.rs
index 11cfd1d1..c4cfa156 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,7 +2,8 @@ use clap::Parser;
 use std::iter;
 use std::sync::LazyLock;
 
-use csvsql::ExactSizeIterable;
+use csvsql::loader::AsRef;
+use csvsql::Record;
 
 fn normalize_col(col: &str) -> String {
     static RE: LazyLock<regex::Regex> = LazyLock::new(|| regex::Regex::new(r"\(.*?\)$").unwrap());
@@ -92,6 +93,7 @@ fn _load_table_from_loader(
             let record = record?;
             let row = record.iter();
             let row_len = row.len();
+            let row = row.map(|v| v.as_ref());
             if row_len > normalized_cols.len() {
                 anyhow::bail!(
                     "Too many fields on row {}, fields: {:?}",