Add ‘each’ function on a value for field iteration

lib/src/sql/part.rs

@@ -23,6 +23,12 @@ pub enum Part {
 	Graph(Graph),
 }
 
+impl From<i32> for Part {
+	fn from(v: i32) -> Self {
+		Part::Index(v.into())
+	}
+}
+
 impl From<isize> for Part {
 	fn from(v: isize) -> Self {
 		Part::Index(v.into())

lib/src/sql/value/each.rs

@@ -0,0 +1,144 @@
+use crate::sql::idiom::Idiom;
+use crate::sql::part::Next;
+use crate::sql::part::Part;
+use crate::sql::value::Value;
+
+impl Value {
+	pub fn each(&self, path: &[Part]) -> Vec<Idiom> {
+		self._each(path, Idiom::default())
+	}
+	fn _each(&self, path: &[Part], prev: Idiom) -> Vec<Idiom> {
+		match path.first() {
+			// Get the current path part
+			Some(p) => match self {
+				// Current path part is an object
+				Value::Object(v) => match p {
+					Part::Field(f) => match v.value.get(&f.name) {
+						Some(v) => v._each(path.next(), prev.add(p.clone())),
+						None => vec![],
+					},
+					Part::All => self._each(path.next(), prev.add(p.clone())),
+					_ => vec![],
+				},
+				// Current path part is an array
+				Value::Array(v) => match p {
+					Part::All => v
+						.value
+						.iter()
+						.enumerate()
+						.flat_map(|(i, v)| v._each(path.next(), prev.add(Part::from(i))))
+						.collect::<Vec<_>>(),
+					Part::First => match v.value.first() {
+						Some(v) => v._each(path.next(), prev.add(p.clone())),
+						None => vec![],
+					},
+					Part::Last => match v.value.last() {
+						Some(v) => v._each(path.next(), prev.add(p.clone())),
+						None => vec![],
+					},
+					Part::Index(i) => match v.value.get(i.to_usize()) {
+						Some(v) => v._each(path.next(), prev.add(p.clone())),
+						None => vec![],
+					},
+					_ => v
+						.value
+						.iter()
+						.enumerate()
+						.flat_map(|(i, v)| v._each(path.next(), prev.add(Part::from(i))))
+						.collect::<Vec<_>>(),
+				},
+				// Ignore everything else
+				_ => vec![],
+			},
+			// No more parts so get the value
+			None => vec![prev],
+		}
+	}
+}
+
+#[cfg(test)]
+mod tests {
+
+	use super::*;
+	use crate::sql::idiom::Idiom;
+	use crate::sql::test::Parse;
+
+	#[test]
+	fn each_none() {
+		let idi = Idiom::default();
+		let val = Value::parse("{ test: { other: null, something: 123 } }");
+		let res = vec![Idiom::default()];
+		assert_eq!(res, val.each(&idi));
+		assert_eq!(val.pick(&res[0]), Value::parse("{ test: { other: null, something: 123 } }"));
+	}
+
+	#[test]
+	fn each_basic() {
+		let idi = Idiom::parse("test.something");
+		let val = Value::parse("{ test: { other: null, something: 123 } }");
+		let res = vec![Idiom::parse("test.something")];
+		assert_eq!(res, val.each(&idi));
+		assert_eq!(val.pick(&res[0]), Value::from(123));
+	}
+
+	#[test]
+	fn each_array() {
+		let idi = Idiom::parse("test.something");
+		let val = Value::parse("{ test: { something: [{ age: 34 }, { age: 36 }] } }");
+		let res = vec![Idiom::parse("test.something")];
+		assert_eq!(res, val.each(&idi));
+		assert_eq!(val.pick(&res[0]), Value::parse("[{ age: 34 }, { age: 36 }]"));
+	}
+
+	#[test]
+	fn each_array_field() {
+		let idi = Idiom::parse("test.something[*].age");
+		let val = Value::parse("{ test: { something: [{ age: 34 }, { age: 36 }] } }");
+		let res =
+			vec![Idiom::parse("test.something[0].age"), Idiom::parse("test.something[1].age")];
+		assert_eq!(res, val.each(&idi));
+		assert_eq!(val.pick(&res[0]), Value::from(34));
+		assert_eq!(val.pick(&res[1]), Value::from(36));
+	}
+
+	#[test]
+	fn each_array_field_embedded() {
+		let idi = Idiom::parse("test.something[*].tags");
+		let val = Value::parse("{ test: { something: [{ age: 34, tags: ['code', 'databases'] }, { age: 36, tags: ['design', 'operations'] }] } }");
+		let res =
+			vec![Idiom::parse("test.something[0].tags"), Idiom::parse("test.something[1].tags")];
+		assert_eq!(res, val.each(&idi));
+		assert_eq!(val.pick(&res[0]), Value::parse("['code', 'databases']"));
+		assert_eq!(val.pick(&res[1]), Value::parse("['design', 'operations']"));
+	}
+
+	#[test]
+	fn each_array_field_embedded_index() {
+		let idi = Idiom::parse("test.something[*].tags[1]");
+		let val = Value::parse("{ test: { something: [{ age: 34, tags: ['code', 'databases'] }, { age: 36, tags: ['design', 'operations'] }] } }");
+		let res = vec![
+			Idiom::parse("test.something[0].tags[1]"),
+			Idiom::parse("test.something[1].tags[1]"),
+		];
+		assert_eq!(res, val.each(&idi));
+		assert_eq!(val.pick(&res[0]), Value::from("databases"));
+		assert_eq!(val.pick(&res[1]), Value::from("operations"));
+	}
+
+	#[test]
+	fn each_array_field_embedded_index_all() {
+		let idi = Idiom::parse("test.something[*].tags[*]");
+		let val = Value::parse("{ test: { something: [{ age: 34, tags: ['code', 'databases'] }, { age: 36, tags: ['design', 'operations'] }] } }");
+		let res = vec![
+			Idiom::parse("test.something[0].tags[0]"),
+			Idiom::parse("test.something[0].tags[1]"),
+			Idiom::parse("test.something[1].tags[0]"),
+			Idiom::parse("test.something[1].tags[1]"),
+		];
+		assert_eq!(res, val.each(&idi));
+		assert_eq!(val.pick(&res[0]), Value::from("code"));
+		assert_eq!(val.pick(&res[1]), Value::from("databases"));
+		assert_eq!(val.pick(&res[2]), Value::from("design"));
+		assert_eq!(val.pick(&res[3]), Value::from("operations"));
+	}
+}

lib/src/sql/value/mod.rs

@@ -8,6 +8,7 @@ mod decrement;
 mod def;
 mod del;
 mod diff;
+mod each;
 mod first;
 mod get;
 mod increment;