Feat struct field optionality (#465)

Add Struct Field Optionality

partiql-logical-planner/src/typer.rs

@@ -779,7 +779,7 @@ mod tests {
     #[test]
     fn simple_sfw_err() {
         // Closed Schema with `Strict` typing mode and `age` non-existent projection.
-        let err1 = r#"No Typing Information for SymbolPrimitive { value: "age", case: CaseInsensitive } in closed Schema Static(StaticType { ty: Struct(StructType { constraints: {Open(false), Fields({StructField { name: "id", ty: Static(StaticType { ty: Int, nullable: true }) }, StructField { name: "name", ty: Static(StaticType { ty: String, nullable: true }) }})} }), nullable: true })"#;
+        let err1 = r#"No Typing Information for SymbolPrimitive { value: "age", case: CaseInsensitive } in closed Schema Static(StaticType { ty: Struct(StructType { constraints: {Open(false), Fields({StructField { optional: false, name: "id", ty: Static(StaticType { ty: Int, nullable: true }) }, StructField { optional: false, name: "name", ty: Static(StaticType { ty: String, nullable: true }) }})} }), nullable: true })"#;
 
         assert_err(
             assert_query_typing(
@@ -813,7 +813,7 @@ mod tests {
             StructConstraint::Open(false)
         ])];
 
-        let err1 = r#"No Typing Information for SymbolPrimitive { value: "details", case: CaseInsensitive } in closed Schema Static(StaticType { ty: Struct(StructType { constraints: {Open(false), Fields({StructField { name: "age", ty: Static(StaticType { ty: Int, nullable: true }) }})} }), nullable: true })"#;
+        let err1 = r#"No Typing Information for SymbolPrimitive { value: "details", case: CaseInsensitive } in closed Schema Static(StaticType { ty: Struct(StructType { constraints: {Open(false), Fields({StructField { optional: false, name: "age", ty: Static(StaticType { ty: Int, nullable: true }) }})} }), nullable: true })"#;
         let err2 = r"Illegal Derive Type Undefined";
 
         assert_err(

partiql-types/src/lib.rs

@@ -572,6 +572,7 @@ pub enum StructConstraint {
 #[derive(Debug, Clone, Eq, PartialEq, Hash, Ord, PartialOrd)]
 #[allow(dead_code)]
 pub struct StructField {
+    optional: bool,
     name: String,
     ty: PartiqlShape,
 }
@@ -582,6 +583,16 @@ impl StructField {
         StructField {
             name: name.to_string(),
             ty,
+            optional: false,
+        }
+    }
+
+    #[must_use]
+    pub fn new_optional(name: &str, ty: PartiqlShape) -> Self {
+        StructField {
+            name: name.to_string(),
+            ty,
+            optional: true,
         }
     }
 
@@ -594,13 +605,29 @@ impl StructField {
     pub fn ty(&self) -> &PartiqlShape {
         &self.ty
     }
+
+    #[must_use]
+    pub fn is_optional(&self) -> &bool {
+        &self.optional
+    }
 }
 
 impl From<(&str, PartiqlShape)> for StructField {
     fn from(value: (&str, PartiqlShape)) -> Self {
         StructField {
             name: value.0.to_string(),
             ty: value.1,
+            optional: false,
+        }
+    }
+}
+
+impl From<(&str, PartiqlShape, bool)> for StructField {
+    fn from(value: (&str, PartiqlShape, bool)) -> Self {
+        StructField {
+            name: value.0.to_string(),
+            ty: value.1,
+            optional: value.2,
         }
     }
 }