From dc184e2b7382091a3a5c71656c17d26e2d962da6 Mon Sep 17 00:00:00 2001
From: rbasralian <rbasralian@deephaven.io>
Date: Wed, 18 Sep 2024 16:24:12 -0400
Subject: [PATCH] include column name in prefix for `checkCastTo` instead

---
 .../deephaven/engine/table/ColumnSource.java  | 60 ++++++++++++++++++-
 .../engine/table/impl/TableDefaults.java      | 11 +---
 2 files changed, 61 insertions(+), 10 deletions(-)

diff --git a/engine/api/src/main/java/io/deephaven/engine/table/ColumnSource.java b/engine/api/src/main/java/io/deephaven/engine/table/ColumnSource.java
index c70c2fe65a0..9ba13992d3d 100644
--- a/engine/api/src/main/java/io/deephaven/engine/table/ColumnSource.java
+++ b/engine/api/src/main/java/io/deephaven/engine/table/ColumnSource.java
@@ -177,8 +177,34 @@ default void exportAllTo(final Object @NotNull [] dest, @NotNull final T tuple)
      */
     @FinalDefault
     default <TYPE> ColumnSource<TYPE> cast(Class<? extends TYPE> clazz) {
+        return cast(clazz, (String) null);
+    }
+
+    /**
+     * Returns this {@code ColumnSource}, parameterized by {@code <TYPE>}, if the data type of this column (as given by
+     * {@link #getType()}) can be cast to {@code clazz}. This is analogous to casting the objects provided by this
+     * column source to {@code clazz}.
+     * <p>
+     * For example, the following code will throw an exception if the "MyString" column does not actually contain
+     * {@code String} data:
+     *
+     * <pre>
+     *     ColumnSource&lt;String&gt; colSource = table.getColumnSource("MyString").cast(String.class)
+     * </pre>
+     * <p>
+     * Due to the nature of type erasure, the JVM will still insert an additional cast to {@code TYPE} when elements are
+     * retrieved from the column source, such as with {@code String myStr = colSource.get(0)}.
+     *
+     * @param clazz The target type.
+     * @param <TYPE> The target type, as a type parameter. Intended to be inferred from {@code clazz}.
+     * @param colName An optional column name, which will be included in exception messages.
+     * @return A {@code ColumnSource} parameterized by {@code TYPE}.
+     */
+    @FinalDefault
+    default <TYPE> ColumnSource<TYPE> cast(Class<? extends TYPE> clazz, @Nullable String colName) {
         Require.neqNull(clazz, "clazz");
-        TypeHelper.checkCastTo("ColumnSource", getType(), clazz);
+        final String castCheckPrefix = colName == null ? "ColumnSource" : "ColumnSource[" + colName + ']';
+        TypeHelper.checkCastTo(castCheckPrefix, getType(), clazz);
         // noinspection unchecked
         return (ColumnSource<TYPE>) this;
     }
@@ -208,8 +234,38 @@ default <TYPE> ColumnSource<TYPE> cast(Class<? extends TYPE> clazz) {
      */
     @FinalDefault
     default <TYPE> ColumnSource<TYPE> cast(Class<? extends TYPE> clazz, @Nullable Class<?> componentType) {
+        return cast(clazz, componentType, null);
+    }
+
+    /**
+     * Returns this {@code ColumnSource}, parameterized by {@code <TYPE>}, if the data type of this column (as given by
+     * {@link #getType()}) can be cast to {@code clazz}. This is analogous to casting the objects provided by this
+     * column source to {@code clazz}. Additionally, this checks that the component type of this column (as given by
+     * {@link #getComponentType()}) can be cast to {@code componentType} (both must be present and castable, or both
+     * must be {@code null}).
+     *
+     * <p>
+     * For example, the following code will throw an exception if the "MyString" column does not actually contain
+     * {@code String} data:
+     *
+     * <pre>
+     *     ColumnSource&lt;String&gt; colSource = table.getColumnSource("MyString").cast(String.class, null)
+     * </pre>
+     * <p>
+     * Due to the nature of type erasure, the JVM will still insert an additional cast to {@code TYPE} when elements are
+     * retrieved from the column source, such as with {@code String myStr = colSource.get(0)}.
+     *
+     * @param clazz The target type.
+     * @param componentType The target component type, may be {@code null}.
+     * @param colName An optional column name, which will be included in exception messages.
+     * @param <TYPE> The target type, as a type parameter. Intended to be inferred from {@code clazz}.
+     * @return A {@code ColumnSource} parameterized by {@code TYPE}.
+     */
+    @FinalDefault
+    default <TYPE> ColumnSource<TYPE> cast(Class<? extends TYPE> clazz, @Nullable Class<?> componentType, @Nullable String colName) {
         Require.neqNull(clazz, "clazz");
-        TypeHelper.checkCastTo("ColumnSource", getType(), getComponentType(), clazz, componentType);
+        final String castCheckPrefix = colName == null ? "ColumnSource" : "ColumnSource[" + colName + ']';
+        TypeHelper.checkCastTo(castCheckPrefix, getType(), getComponentType(), clazz, componentType);
         // noinspection unchecked
         return (ColumnSource<TYPE>) this;
     }
diff --git a/engine/table/src/main/java/io/deephaven/engine/table/impl/TableDefaults.java b/engine/table/src/main/java/io/deephaven/engine/table/impl/TableDefaults.java
index 95ae43d0498..d815bc5bd22 100644
--- a/engine/table/src/main/java/io/deephaven/engine/table/impl/TableDefaults.java
+++ b/engine/table/src/main/java/io/deephaven/engine/table/impl/TableDefaults.java
@@ -99,7 +99,7 @@ default <T> ColumnSource<T> getColumnSource(String sourceName, Class<? extends T
         @SuppressWarnings("rawtypes")
         ColumnSource rawColumnSource = getColumnSource(sourceName);
         // noinspection unchecked
-        return rawColumnSource.cast(clazz);
+        return rawColumnSource.cast(clazz, sourceName);
     }
 
     @Override
@@ -108,13 +108,8 @@ default <T> ColumnSource<T> getColumnSource(String sourceName, Class<? extends T
             @Nullable Class<?> componentType) {
         @SuppressWarnings("rawtypes")
         ColumnSource rawColumnSource = getColumnSource(sourceName);
-        try {
-            // noinspection unchecked
-            return rawColumnSource.cast(clazz, componentType);
-        } catch (ClassCastException ex) {
-            throw new RuntimeException(
-                    "Error retrieving ColumnSource with type " + clazz.getName() + " for column " + sourceName, ex);
-        }
+        // noinspection unchecked
+        return rawColumnSource.cast(clazz, componentType, sourceName);
     }
 
     // -----------------------------------------------------------------------------------------------------------------