Doc gen: Attributes to support related_udf, alternative_syntax (#13575)

* Doc gen: Rust custom attributes support `related_udf`, `alternative_syntax`

Author: comphead

datafusion/doc/src/lib.rs

@@ -56,8 +56,12 @@ pub struct Documentation {
 
 impl Documentation {
     /// Returns a new [`DocumentationBuilder`] with no options set.
-    pub fn builder() -> DocumentationBuilder {
-        DocumentationBuilder::new()
+    pub fn builder(
+        doc_section: DocSection,
+        description: impl Into<String>,
+        syntax_example: impl Into<String>,
+    ) -> DocumentationBuilder {
+        DocumentationBuilder::new(doc_section, description, syntax_example)
     }
 }
 
@@ -86,29 +90,30 @@ pub struct DocSection {
 ///         description: None,
 ///     };
 ///
-///     let documentation = Documentation::builder()
-///           .with_doc_section(doc_section)
-///           .with_description("Add one to an int32")
-///           .with_syntax_example("add_one(2)")
+///     let documentation = Documentation::builder(doc_section, "Add one to an int32".to_owned(), "add_one(2)".to_owned())
 ///           .with_argument("arg_1", "The int32 number to add one to")
 ///           .build();
 /// # }
 pub struct DocumentationBuilder {
-    pub doc_section: Option<DocSection>,
-    pub description: Option<String>,
-    pub syntax_example: Option<String>,
+    pub doc_section: DocSection,
+    pub description: String,
+    pub syntax_example: String,
     pub sql_example: Option<String>,
     pub arguments: Option<Vec<(String, String)>>,
     pub alternative_syntax: Option<Vec<String>>,
     pub related_udfs: Option<Vec<String>>,
 }
 
 impl DocumentationBuilder {
-    pub fn new() -> Self {
+    pub fn new(
+        doc_section: DocSection,
+        description: impl Into<String>,
+        syntax_example: impl Into<String>,
+    ) -> Self {
         Self {
-            doc_section: None,
-            description: None,
-            syntax_example: None,
+            doc_section,
+            description: description.into(),
+            syntax_example: syntax_example.into(),
             sql_example: None,
             arguments: None,
             alternative_syntax: None,
@@ -117,17 +122,17 @@ impl DocumentationBuilder {
     }
 
     pub fn with_doc_section(mut self, doc_section: DocSection) -> Self {
-        self.doc_section = Some(doc_section);
+        self.doc_section = doc_section;
         self
     }
 
     pub fn with_description(mut self, description: impl Into<String>) -> Self {
-        self.description = Some(description.into());
+        self.description = description.into();
         self
     }
 
     pub fn with_syntax_example(mut self, syntax_example: impl Into<String>) -> Self {
-        self.syntax_example = Some(syntax_example.into());
+        self.syntax_example = syntax_example.into();
         self
     }
 
@@ -205,30 +210,14 @@ impl DocumentationBuilder {
             related_udfs,
         } = self;
 
-        if doc_section.is_none() {
-            panic!("Documentation must have a doc section");
-        }
-        if description.is_none() {
-            panic!("Documentation must have a description");
-        }
-        if syntax_example.is_none() {
-            panic!("Documentation must have a syntax_example");
-        }
-
         Documentation {
-            doc_section: doc_section.unwrap(),
-            description: description.unwrap(),
-            syntax_example: syntax_example.unwrap(),
+            doc_section,
+            description,
+            syntax_example,
             sql_example,
             arguments,
             alternative_syntax,
             related_udfs,
         }
     }
 }
-
-impl Default for DocumentationBuilder {
-    fn default() -> Self {
-        Self::new()
-    }
-}

datafusion/expr/src/udaf.rs

@@ -333,10 +333,7 @@ where
 ///
 /// fn get_doc() -> &'static Documentation {
 ///     DOCUMENTATION.get_or_init(|| {
-///         Documentation::builder()
-///             .with_doc_section(DOC_SECTION_AGGREGATE)
-///             .with_description("calculates a geometric mean")
-///             .with_syntax_example("geo_mean(2.0)")
+///         Documentation::builder(DOC_SECTION_AGGREGATE, "calculates a geometric mean", "geo_mean(2.0)")
 ///             .with_argument("arg1", "The Float64 number for the geometric mean")
 ///             .build()
 ///     })

datafusion/expr/src/udf.rs

@@ -374,10 +374,7 @@ pub struct ScalarFunctionArgs<'a> {
 ///
 /// fn get_doc() -> &'static Documentation {
 ///     DOCUMENTATION.get_or_init(|| {
-///         Documentation::builder()
-///             .with_doc_section(DOC_SECTION_MATH)
-///             .with_description("Add one to an int32")
-///             .with_syntax_example("add_one(2)")
+///         Documentation::builder(DOC_SECTION_MATH, "Add one to an int32", "add_one(2)")
 ///             .with_argument("arg1", "The int32 number to add one to")
 ///             .build()
 ///     })

datafusion/expr/src/udwf.rs

@@ -258,10 +258,7 @@ where
 ///
 /// fn get_doc() -> &'static Documentation {
 ///     DOCUMENTATION.get_or_init(|| {
-///         Documentation::builder()
-///             .with_doc_section(DOC_SECTION_ANALYTICAL)
-///             .with_description("smooths the windows")
-///             .with_syntax_example("smooth_it(2)")
+///         Documentation::builder(DOC_SECTION_ANALYTICAL, "smooths the windows", "smooth_it(2)")
 ///             .with_argument("arg1", "The int32 number to smooth by")
 ///             .build()
 ///     })

datafusion/functions-aggregate/src/approx_distinct.rs

@@ -317,12 +317,7 @@ static DOCUMENTATION: OnceLock<Documentation> = OnceLock::new();
 
 fn get_approx_distinct_doc() -> &'static Documentation {
     DOCUMENTATION.get_or_init(|| {
-        Documentation::builder()
-            .with_doc_section(DOC_SECTION_APPROXIMATE)
-            .with_description(
-                "Returns the approximate number of distinct input values calculated using the HyperLogLog algorithm.",
-            )
-            .with_syntax_example("approx_distinct(expression)")
+        Documentation::builder(DOC_SECTION_APPROXIMATE, "Returns the approximate number of distinct input values calculated using the HyperLogLog algorithm.", "approx_distinct(expression)")
             .with_sql_example(r#"```sql
 > SELECT approx_distinct(column_name) FROM table_name;
 +-----------------------------------+

datafusion/functions-aggregate/src/approx_median.rs

@@ -130,12 +130,11 @@ static DOCUMENTATION: OnceLock<Documentation> = OnceLock::new();
 
 fn get_approx_median_doc() -> &'static Documentation {
     DOCUMENTATION.get_or_init(|| {
-        Documentation::builder()
-            .with_doc_section(DOC_SECTION_APPROXIMATE)
-            .with_description(
+        Documentation::builder(
+            DOC_SECTION_APPROXIMATE,
                 "Returns the approximate median (50th percentile) of input values. It is an alias of `approx_percentile_cont(x, 0.5)`.",
-            )
-            .with_syntax_example("approx_median(expression)")
+
+            "approx_median(expression)")
             .with_sql_example(r#"```sql
 > SELECT approx_median(column_name) FROM table_name;
 +-----------------------------------+

datafusion/functions-aggregate/src/approx_percentile_cont.rs

@@ -280,12 +280,10 @@ static DOCUMENTATION: OnceLock<Documentation> = OnceLock::new();
 
 fn get_approx_percentile_cont_doc() -> &'static Documentation {
     DOCUMENTATION.get_or_init(|| {
-        Documentation::builder()
-            .with_doc_section(DOC_SECTION_APPROXIMATE)
-            .with_description(
+        Documentation::builder(
+            DOC_SECTION_APPROXIMATE,
                 "Returns the approximate percentile of input values using the t-digest algorithm.",
-            )
-            .with_syntax_example("approx_percentile_cont(expression, percentile, centroids)")
+            "approx_percentile_cont(expression, percentile, centroids)")
             .with_sql_example(r#"```sql
 > SELECT approx_percentile_cont(column_name, 0.75, 100) FROM table_name;
 +-------------------------------------------------+

datafusion/functions-aggregate/src/approx_percentile_cont_with_weight.rs

@@ -165,12 +165,11 @@ static DOCUMENTATION: OnceLock<Documentation> = OnceLock::new();
 
 fn get_approx_percentile_cont_with_weight_doc() -> &'static Documentation {
     DOCUMENTATION.get_or_init(|| {
-        Documentation::builder()
-            .with_doc_section(DOC_SECTION_APPROXIMATE)
-            .with_description(
+        Documentation::builder(
+            DOC_SECTION_APPROXIMATE,
                 "Returns the weighted approximate percentile of input values using the t-digest algorithm.",
-            )
-            .with_syntax_example("approx_percentile_cont_with_weight(expression, weight, percentile)")
+
+            "approx_percentile_cont_with_weight(expression, weight, percentile)")
             .with_sql_example(r#"```sql
 > SELECT approx_percentile_cont_with_weight(column_name, weight_column, 0.90) FROM table_name;
 +----------------------------------------------------------------------+

datafusion/functions-aggregate/src/array_agg.rs

@@ -154,12 +154,11 @@ static DOCUMENTATION: OnceLock<Documentation> = OnceLock::new();
 
 fn get_array_agg_doc() -> &'static Documentation {
     DOCUMENTATION.get_or_init(|| {
-        Documentation::builder()
-            .with_doc_section(DOC_SECTION_GENERAL)
-            .with_description(
+        Documentation::builder(
+            DOC_SECTION_GENERAL,
                 "Returns an array created from the expression elements. If ordering is required, elements are inserted in the specified order.",
-            )
-            .with_syntax_example("array_agg(expression [ORDER BY expression])")
+
+            "array_agg(expression [ORDER BY expression])")
             .with_sql_example(r#"```sql
 > SELECT array_agg(column_name ORDER BY other_column) FROM table_name;
 +-----------------------------------------------+

datafusion/functions-aggregate/src/average.rs

@@ -248,24 +248,23 @@ static DOCUMENTATION: OnceLock<Documentation> = OnceLock::new();
 
 fn get_avg_doc() -> &'static Documentation {
     DOCUMENTATION.get_or_init(|| {
-        Documentation::builder()
-            .with_doc_section(DOC_SECTION_GENERAL)
-            .with_description(
-                "Returns the average of numeric values in the specified column.",
-            )
-            .with_syntax_example("avg(expression)")
-            .with_sql_example(
-                r#"```sql
+        Documentation::builder(
+            DOC_SECTION_GENERAL,
+            "Returns the average of numeric values in the specified column.",
+            "avg(expression)",
+        )
+        .with_sql_example(
+            r#"```sql
 > SELECT avg(column_name) FROM table_name;
 +---------------------------+
 | avg(column_name)           |
 +---------------------------+
 | 42.75                      |
 +---------------------------+
 ```"#,
-            )
-            .with_standard_argument("expression", None)
-            .build()
+        )
+        .with_standard_argument("expression", None)
+        .build()
     })
 }