refactor; add order() fn; add examples

Cargo.lock

@@ -19,7 +19,7 @@ checksum = "b1a46d1a171d865aa5f83f92695765caa047a9b4cbae2cbf37dbd613a793fd4c"
 
 [[package]]
 name = "jsonfilter"
-version = "0.1.0"
+version = "0.2.0"
 dependencies = [
  "regex",
  "serde",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "jsonfilter"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2021"
 
 [dependencies]

README.md

@@ -1,2 +1,32 @@
 # JSONFilter
-JSONFilter is a rust crate letting you filter JSON objects based on another json object as a filter. Think of MongoDBs `find()` function but as a filter.
+`jsonfilter` is a Rust crate designed to facilitate filtering and comparing JSON values based on specified criteria. It provides functions for comparing JSON values, applying filters to JSON objects, and determining if a filter matches a given JSON object. Think of MongoDBs `find()` function but as a filter function.
+
+## Usage
+To use `jsonfilter`, add it to your `Cargo.toml` and add the following to your Rust code:
+```rust
+use jsonfilter::{order, matches};
+```
+
+### Comparing JSON Values
+You can compare two JSON values using the `order` function:
+```rust
+use serde_json::json;
+use std::cmp::Ordering;
+use jsonfilter::order;
+
+let a = json!(10);
+let b = json!(5);
+assert_eq!(order(&a, &b), Ordering::Greater);
+```
+
+### Matching Filters
+To check if a JSON object matches a filter, use the `matches` function:
+```rust
+use serde_json::json;
+use jsonfilter::matches;
+
+let filter = json!({"name": "John", "age": 30});
+let obj = json!({"name": "John", "age": 30, "city": "New York"});
+
+assert!(matches(&filter, &obj));
+```

examples/array.rs

@@ -0,0 +1,38 @@
+use jsonfilter::{try_matches, FilterError};
+use serde_json::{json, Value};
+
+fn main() {
+    let filter = json!({"$or": [{"tags": {"$in": "programming"}},{"tags": {"$in": "rust"}}]});
+
+    let obj1 = json!({"name": "John Doe", "tags": ["rust", "programming", "development"]});
+    let obj2 = json!({"name": "Alice Smith", "tags": ["web", "development", "javascript"]});
+    let obj3 = json!({"name": "Bob Brown", "tags": ["python", "programming", "machine learning"]});
+
+    println!("Filter:");
+    println!("{}", filter);
+    println!("Objects:");
+    println!("Object 1: {}", obj1);
+    println!("Object 2: {}", obj2);
+    println!("Object 3: {}", obj3);
+
+    match_objects(&filter, &obj1);
+    match_objects(&filter, &obj2);
+    match_objects(&filter, &obj3);
+}
+
+fn match_objects(filter: &Value, obj: &Value) {
+    match try_matches(filter, obj) {
+        Ok(result) => {
+            if result {
+                println!("Filter matches the object");
+            } else {
+                println!("Filter does not match the object");
+            }
+        }
+        Err(err) => match err {
+            FilterError::InvalidFilter => println!("Invalid filter"),
+            FilterError::UnknownOperator => println!("Unknown operator in filter"),
+            FilterError::KeyNotFound => println!("Key not found in object"),
+        },
+    }
+}

examples/comparison.rs

@@ -0,0 +1,16 @@
+use jsonfilter::order;
+use serde_json::json;
+use std::cmp::Ordering;
+
+fn main() {
+    let a = json!(10);
+    let b = json!(5);
+    println!("Comparing JSON values:");
+    println!("a: {}", a);
+    println!("b: {}", b);
+    match order(&a, &b) {
+        Ordering::Greater => println!("a is greater than b"),
+        Ordering::Less => println!("a is less than b"),
+        Ordering::Equal => println!("a is equal to b"),
+    }
+}

examples/error_handling.rs

@@ -0,0 +1,28 @@
+use jsonfilter::{try_matches, FilterError};
+use serde_json::json;
+
+fn main() {
+    let filter = json!({"name": "John", "other": "key"});
+    let obj = json!({"name": "John", "age": 30});
+
+    println!("Applying filter:");
+    println!("{}", filter);
+    println!("To object:");
+    println!("{}", obj);
+
+    match try_matches(&filter, &obj) {
+        Ok(result) => {
+            if result {
+                println!("Filter matches the object");
+            } else {
+                println!("Filter does not match the object");
+            }
+        }
+        // FilterError::KeyNotFound mostly means the object did not pass the filter, but it's still an error though
+        Err(err) => match err {
+            FilterError::InvalidFilter => println!("Invalid filter"),
+            FilterError::UnknownOperator => println!("Unknown operator in filter"),
+            FilterError::KeyNotFound => println!("Key not found in object"),
+        },
+    }
+}

examples/filter.rs

@@ -0,0 +1,17 @@
+use jsonfilter::matches;
+use serde_json::json;
+
+fn main() {
+    let filter = json!({"name": "John", "age": 30});
+    let obj = json!({"name": "John", "age": 30, "city": "New York"});
+
+    println!("Applying filter:");
+    println!("{}", filter);
+    println!("To object:");
+    println!("{}", obj);
+    if matches(&filter, &obj) {
+        println!("Filter matches the object");
+    } else {
+        println!("Filter does not match the object");
+    }
+}

examples/nested_filters.rs

@@ -0,0 +1,53 @@
+use jsonfilter::{try_matches, FilterError};
+use serde_json::{json, Value};
+
+fn main() {
+    // Filter can be as complex as you want
+    let filter = json!({
+        "$and": [
+            {"$or": [
+                {"age": {"$gte": 18}},
+                {"is_student": true}
+            ]},
+            {"$not": {
+                "$or": [
+                    {"city": "New York"},
+                    {"city": "Los Angeles"}
+                ]
+            }}
+        ]
+    });
+
+    let obj1 = json!({"age": 25, "is_student": false, "city": "Chicago"});
+    let obj2 = json!({"age": 16, "is_student": true, "city": "Miami"});
+    let obj3 = json!({"age": 30, "is_student": false, "city": "New York"});
+
+    println!("Filter:");
+    println!("{}", filter);
+    println!("Objects:");
+    println!("Object 1: {}", obj1);
+    println!("Object 2: {}", obj2);
+    println!("Object 3: {}", obj3);
+
+    // Matching objects against the filter
+    match_objects(&filter, &obj1);
+    match_objects(&filter, &obj2);
+    match_objects(&filter, &obj3);
+}
+
+fn match_objects(filter: &Value, obj: &Value) {
+    match try_matches(filter, obj) {
+        Ok(result) => {
+            if result {
+                println!("Filter matches the object");
+            } else {
+                println!("Filter does not match the object");
+            }
+        }
+        Err(err) => match err {
+            FilterError::InvalidFilter => println!("Invalid filter"),
+            FilterError::UnknownOperator => println!("Unknown operator in filter"),
+            FilterError::KeyNotFound => println!("Key not found in object"),
+        },
+    }
+}

examples/range.rs

@@ -0,0 +1,38 @@
+use jsonfilter::{try_matches, FilterError};
+use serde_json::{json, Value};
+
+fn main() {
+    let filter = json!({"$and": [{"age": {"$gte": 18}}, {"age": {"$lte": 30}}]});
+
+    let obj1 = json!({"name": "John Doe", "age": 25});
+    let obj2 = json!({"name": "Alice Smith", "age": 35});
+    let obj3 = json!({"name": "Bob Brown", "age": 20});
+
+    println!("Filter:");
+    println!("{}", filter);
+    println!("Objects:");
+    println!("Object 1: {}", obj1);
+    println!("Object 2: {}", obj2);
+    println!("Object 3: {}", obj3);
+
+    match_objects(&filter, &obj1);
+    match_objects(&filter, &obj2);
+    match_objects(&filter, &obj3);
+}
+
+fn match_objects(filter: &Value, obj: &Value) {
+    match try_matches(filter, obj) {
+        Ok(result) => {
+            if result {
+                println!("Filter matches the object");
+            } else {
+                println!("Filter does not match the object");
+            }
+        }
+        Err(err) => match err {
+            FilterError::InvalidFilter => println!("Invalid filter"),
+            FilterError::UnknownOperator => println!("Unknown operator in filter"),
+            FilterError::KeyNotFound => println!("Key not found in object"),
+        },
+    }
+}

examples/regex.rs

@@ -0,0 +1,39 @@
+use jsonfilter::{try_matches, FilterError};
+use serde_json::{json, Value};
+
+fn main() {
+    // You can filter text with regex
+    let filter = json!({"description": {"$regex": "(Rust|Python)"}});
+
+    let obj1 = json!({"name": "John Doe", "description": "Enthusiastic about programming in Rust"});
+    let obj2 = json!({"name": "Alice Smith", "description": "Experienced in web development"});
+    let obj3 = json!({"name": "Bob Brown", "description": "Loves to code in Python"});
+
+    println!("Filter:");
+    println!("{}", filter);
+    println!("Objects:");
+    println!("Object 1: {}", obj1);
+    println!("Object 2: {}", obj2);
+    println!("Object 3: {}", obj3);
+
+    match_objects(&filter, &obj1);
+    match_objects(&filter, &obj2);
+    match_objects(&filter, &obj3);
+}
+
+fn match_objects(filter: &Value, obj: &Value) {
+    match try_matches(filter, obj) {
+        Ok(result) => {
+            if result {
+                println!("Filter matches the object");
+            } else {
+                println!("Filter does not match the object");
+            }
+        }
+        Err(err) => match err {
+            FilterError::InvalidFilter => println!("Invalid filter"),
+            FilterError::UnknownOperator => println!("Unknown operator in filter"),
+            FilterError::KeyNotFound => println!("Key not found in object"),
+        },
+    }
+}

src/lib.rs

@@ -1,6 +1,73 @@
 mod test;
+use std::cmp::Ordering;
+
 use serde_json::json;
 
+/// Compares two JSON values `a` and `b` based on their ordering.
+///
+/// This function evaluates the relationship between the JSON values `a` and `b` using the following criteria:
+/// - If `a` is greater than `b`, returns `std::cmp::Ordering::Greater`.
+/// - If `a` is less than `b`, returns `std::cmp::Ordering::Less`.
+/// - If `a` is equal to `b`, returns `std::cmp::Ordering::Equal`.
+///
+/// # Arguments
+///
+/// * `a` - A reference to a `serde_json::Value` representing the first JSON value.
+/// * `b` - A reference to a `serde_json::Value` representing the second JSON value.
+///
+/// # Returns
+///
+/// Returns `std::cmp::Ordering` indicating the relationship between `a` and `b`.
+///
+/// # Panics
+///
+/// This function panics if the values cant be compared.
+///
+/// # Examples
+///
+/// ```
+/// use serde_json::json;
+/// use std::cmp::Ordering;
+/// use jsonfilter::order;
+///
+/// let a = json!(10);
+/// let b = json!(5);
+/// assert_eq!(order(&a, &b), Ordering::Greater);
+/// ```
+#[must_use]
+pub fn order(a: &serde_json::Value, b: &serde_json::Value) -> std::cmp::Ordering {
+    if matches(
+        &serde_json::json!({
+            "a": { "$gt": b}
+        }),
+        &serde_json::json!({
+            "a": a
+        }),
+    ) {
+        Ordering::Greater
+    } else if matches(
+        &serde_json::json!({
+            "a": { "$lt": b}
+        }),
+        &serde_json::json!({
+            "a": a
+        }),
+    ) {
+        Ordering::Less
+    } else if matches(
+        &serde_json::json!({
+            "a": b
+        }),
+        &serde_json::json!({
+            "a": a
+        }),
+    ) {
+        Ordering::Equal
+    } else {
+        unreachable!()
+    }
+}
+
 fn less_than_num(a: &serde_json::Value, b: &serde_json::Value) -> bool {
     if a.is_f64() {
         let a = a.as_f64().unwrap();
@@ -14,8 +81,12 @@ fn less_than_num(a: &serde_json::Value, b: &serde_json::Value) -> bool {
         let a = a.as_u64().unwrap();
         let b = b.as_u64().unwrap();
         a < b
+    } else if a.is_string() {
+        let a = a.as_str().unwrap();
+        let b = b.as_str().unwrap();
+        a < b
     } else {
-        false
+        unreachable!()
     }
 }
 
@@ -32,8 +103,12 @@ fn greater_than_num(a: &serde_json::Value, b: &serde_json::Value) -> bool {
         let a = a.as_u64().unwrap();
         let b = b.as_u64().unwrap();
         a > b
+    } else if a.is_string() {
+        let a = a.as_str().unwrap();
+        let b = b.as_str().unwrap();
+        a > b
     } else {
-        false
+        unreachable!()
     }
 }
 
@@ -89,21 +164,34 @@ pub fn try_matches(
         match op.as_str() {
             "$and" => {
                 if let serde_json::Value::Array(and_list) = op_arg {
-                    let and_list_bool: Vec<bool> = and_list
+                    let and_list_bool: Vec<Result<bool, FilterError>> = and_list
                         .iter()
-                        .map(|sub_filter| matches(sub_filter, obj))
+                        .map(|sub_filter| try_matches(sub_filter, obj))
                         .collect();
-                    return Ok(!and_list_bool.iter().any(|x| !x));
+                    if let Some(err) = and_list_bool.iter().find(|x| x.is_err()) {
+                        return *err;
+                    }
+                    return Ok(!and_list_bool.iter().map(|x| x.unwrap()).any(|x| !x));
                 }
                 return Err(FilterError::InvalidFilter);
             }
             "$or" => {
                 if let serde_json::Value::Array(or_list) = op_arg {
-                    let or_list_bool: Vec<bool> = or_list
+                    let or_list_bool: Vec<Result<bool, FilterError>> = or_list
                         .iter()
-                        .map(|sub_filter| matches(sub_filter, obj))
+                        .map(|sub_filter| try_matches(sub_filter, obj))
                         .collect();
-                    return Ok(or_list_bool.iter().any(|x| *x));
+                    if let Some(err) = or_list_bool.iter().find(|x| x.is_err()) {
+                        return *err;
+                    }
+                    return Ok(or_list_bool.iter().map(|x| x.unwrap()).any(|x| x));
+                }
+                return Err(FilterError::InvalidFilter);
+            }
+            "$not" => {
+                if let Some(inner) = filter.get("$not") {
+                    let new_filter = inner;
+                    return Ok(!try_matches(new_filter, obj)?);
                 }
                 return Err(FilterError::InvalidFilter);
             }
@@ -145,6 +233,10 @@ pub fn try_matches(
         }
     }
 
+    check(&conditions)
+}
+
+fn check(conditions: &[Result<bool, FilterError>]) -> Result<bool, FilterError> {
     conditions.iter().find(|x| x.is_err()).map_or_else(
         || Ok(!conditions.iter().map(|x| x.unwrap()).any(|x| !x)),
         |possible_error| *possible_error,
@@ -163,6 +255,32 @@ fn match_operator(
         let op = keys.first().unwrap().as_str();
         let op_arg = val.get(op).unwrap();
         match op {
+            "$and" => {
+                if let serde_json::Value::Array(and_list) = op_arg {
+                    let and_list_bool: Vec<Result<bool, FilterError>> = and_list
+                        .iter()
+                        .map(|sub_filter| try_matches(sub_filter, raw_obj))
+                        .collect();
+                    if let Some(err) = and_list_bool.iter().find(|x| x.is_err()) {
+                        return *err;
+                    }
+                    return Ok(!and_list_bool.iter().map(|x| x.unwrap()).any(|x| !x));
+                }
+                return Err(FilterError::InvalidFilter);
+            }
+            "$or" => {
+                if let serde_json::Value::Array(or_list) = op_arg {
+                    let or_list_bool: Vec<Result<bool, FilterError>> = or_list
+                        .iter()
+                        .map(|sub_filter| try_matches(sub_filter, raw_obj))
+                        .collect();
+                    if let Some(err) = or_list_bool.iter().find(|x| x.is_err()) {
+                        return *err;
+                    }
+                    return Ok(or_list_bool.iter().map(|x| x.unwrap()).any(|x| x));
+                }
+                return Err(FilterError::InvalidFilter);
+            }
             "$lt" => {
                 if let Some(a) = obj.get(key) {
                     return Ok(less_than_num(a, op_arg));