From 4b7ff2488f8324c0c093ea21106799aa392a5cb4 Mon Sep 17 00:00:00 2001
From: Andrew Lamb <andrew@nerdnetworks.org>
Date: Sat, 4 Nov 2023 06:24:23 -0400
Subject: [PATCH 1/2] Minor: improve documentation for IsNotNull, DISTINCT, etc

---
 datafusion/expr/src/expr.rs     | 16 ++++++++--------
 datafusion/expr/src/operator.rs |  8 ++++++--
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/datafusion/expr/src/expr.rs b/datafusion/expr/src/expr.rs
index 239a3188502c..8929b21f4412 100644
--- a/datafusion/expr/src/expr.rs
+++ b/datafusion/expr/src/expr.rs
@@ -99,21 +99,21 @@ pub enum Expr {
     SimilarTo(Like),
     /// Negation of an expression. The expression's type must be a boolean to make sense.
     Not(Box<Expr>),
-    /// Whether an expression is not Null. This expression is never null.
+    /// True if argument is not NULL, false otherwise. This expression itself is never NULL.
     IsNotNull(Box<Expr>),
-    /// Whether an expression is Null. This expression is never null.
+    /// True if argument is NULL, false otherwise. This expression itself is never NULL.
     IsNull(Box<Expr>),
-    /// Whether an expression is True. Boolean operation
+    /// True if argument is true, false otherwise. This expression itself is never NULL.
     IsTrue(Box<Expr>),
-    /// Whether an expression is False. Boolean operation
+    /// True if argument is  false, false otherwise. This expression itself is never NULL.
     IsFalse(Box<Expr>),
-    /// Whether an expression is Unknown. Boolean operation
+    /// True if argument is NULL, false otherwise. This expression itself is never NULL.
     IsUnknown(Box<Expr>),
-    /// Whether an expression is not True. Boolean operation
+    /// True if argument is FALSE or NULL, false otherwise. This expression itself is never NULL.
     IsNotTrue(Box<Expr>),
-    /// Whether an expression is not False. Boolean operation
+    /// True if argument is TRUE OR NULL, false otherwise. This expression itself is never NULL.
     IsNotFalse(Box<Expr>),
-    /// Whether an expression is not Unknown. Boolean operation
+    /// True if argument is TRUE or FALSE, false otherwise. This expression itself is never NULL.
     IsNotUnknown(Box<Expr>),
     /// arithmetic negation of an expression, the operand must be of a signed numeric data type
     Negative(Box<Expr>),
diff --git a/datafusion/expr/src/operator.rs b/datafusion/expr/src/operator.rs
index 1790f1478927..b5394fac53a4 100644
--- a/datafusion/expr/src/operator.rs
+++ b/datafusion/expr/src/operator.rs
@@ -53,9 +53,13 @@ pub enum Operator {
     And,
     /// Logical OR, like `||`
     Or,
-    /// IS DISTINCT FROM
+    /// `IS DISTINCT FROM` (see [`distinct`])
+    ///
+    /// [distinct]: arrow::compute::kernels::cmp::distinct
     IsDistinctFrom,
-    /// IS NOT DISTINCT FROM
+    /// `IS NOT DISTINCT FROM` (see [`not_distinct`])
+    ///
+    /// [not_distinct]: arrow::compute::kernels::cmp::not_distinct
     IsNotDistinctFrom,
     /// Case sensitive regex match
     RegexMatch,

From b85b91c5119417d28d6d2de1d7aea8e603e4188a Mon Sep 17 00:00:00 2001
From: Andrew Lamb <andrew@nerdnetworks.org>
Date: Sat, 4 Nov 2023 06:34:09 -0400
Subject: [PATCH 2/2] fix

---
 datafusion/expr/src/operator.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/datafusion/expr/src/operator.rs b/datafusion/expr/src/operator.rs
index b5394fac53a4..57888a11d426 100644
--- a/datafusion/expr/src/operator.rs
+++ b/datafusion/expr/src/operator.rs
@@ -55,11 +55,11 @@ pub enum Operator {
     Or,
     /// `IS DISTINCT FROM` (see [`distinct`])
     ///
-    /// [distinct]: arrow::compute::kernels::cmp::distinct
+    /// [`distinct`]: arrow::compute::kernels::cmp::distinct
     IsDistinctFrom,
     /// `IS NOT DISTINCT FROM` (see [`not_distinct`])
     ///
-    /// [not_distinct]: arrow::compute::kernels::cmp::not_distinct
+    /// [`not_distinct`]: arrow::compute::kernels::cmp::not_distinct
     IsNotDistinctFrom,
     /// Case sensitive regex match
     RegexMatch,