feat: Add regex feature flag

This hides the regex functions (`match` and `search`) behind a feature flag `regex`, which is enabled by default. This allows consumers to completely eliminate regex as a dependency if they choose.

Also added some docs on feature flags.

serde_json_path/CHANGELOG.md

@@ -8,6 +8,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 # Unreleased
 
 - **fixed**: edge case where `.` in regexes for `match` and `search` functions was matching `\r\n` properly ([#92])
+- **breaking**: added `regex` feature flag that gates regex functions `match` and `search`
+    - Feature is enabled by default, but if you have `default-features = false` you'll need to explicitly add it to retain access to these functions
 
 [#92]: https://github.com/hiltontj/serde_json_path/pull/92
 

serde_json_path/Cargo.toml

@@ -11,15 +11,16 @@ readme = "README.md"
 keywords = ["json", "jsonpath", "json_path", "serde", "serde_json"]
 
 [features]
-default = ["functions"]
+default = ["functions", "regex"]
+regex = ["dep:regex"]
 trace = ["dep:tracing", "serde_json_path_core/trace"]
 functions = ["serde_json_path_core/functions"]
 
 [dependencies]
 inventory = { version = "0.3.4" }
 nom = "7.1.3"
 once_cell = { version = "1.17.1" }
-regex = "1.7.1"
+regex = { version="1.7.1", optional = true }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 serde_json_path_core = { path = "../serde_json_path_core", version = "0.1.6" }

serde_json_path/src/lib.rs

@@ -311,6 +311,14 @@
 //! # Ok(())
 //! # }
 //! ```
+//!
+//! ## Feature Flags
+//!
+//! The following feature flags are supported:
+//!
+//! - `tracing` - Enable internal tracing via [tracing]
+//! - `functions` - Enable user-defined functions
+//! - `regex` - Enable the `match` and `search` functions
 
 #![warn(
     clippy::all,

serde_json_path/src/parser/selector/function/registry.rs

@@ -1,7 +1,6 @@
 use std::collections::HashMap;
 
 use once_cell::sync::Lazy;
-use regex::Regex;
 use serde_json::Value;
 use serde_json_path_core::spec::functions::{Function, LogicalType, NodesType, ValueType};
 
@@ -20,8 +19,11 @@ pub(crate) static REGISTRY: Lazy<HashMap<&'static str, &'static Function>> = Laz
     let mut m = HashMap::new();
     m.insert("length", &LENGTH_FUNC);
     m.insert("count", &COUNT_FUNC);
-    m.insert("match", &MATCH_FUNC);
-    m.insert("search", &SEARCH_FUNC);
+    #[cfg(feature = "regex")]
+    {
+        m.insert("match", &MATCH_FUNC);
+        m.insert("search", &SEARCH_FUNC);
+    }
     m.insert("value", &VALUE_FUNC);
     m
 });
@@ -50,11 +52,12 @@ fn count(nodes: NodesType) -> ValueType {
     nodes.len().into()
 }
 
+#[cfg(feature = "regex")]
 #[serde_json_path_macros::register(name = "match", target = MATCH_FUNC)]
 fn match_func(value: ValueType, rgx: ValueType) -> LogicalType {
     match (value.as_value(), rgx.as_value()) {
         (Some(Value::String(s)), Some(Value::String(r))) => {
-            Regex::new(format!("(?R)^({r})$").as_str())
+            regex::Regex::new(format!("(?R)^({r})$").as_str())
                 .map(|r| r.is_match(s))
                 .map(Into::into)
                 .unwrap_or_default()
@@ -63,11 +66,12 @@ fn match_func(value: ValueType, rgx: ValueType) -> LogicalType {
     }
 }
 
+#[cfg(feature = "regex")]
 #[serde_json_path_macros::register(target = SEARCH_FUNC)]
 fn search(value: ValueType, rgx: ValueType) -> LogicalType {
     match (value.as_value(), rgx.as_value()) {
         (Some(Value::String(s)), Some(Value::String(r))) => {
-            Regex::new(format!("(?R)({r})").as_str())
+            regex::Regex::new(format!("(?R)({r})").as_str())
                 .map(|r| r.is_match(s))
                 .map(Into::into)
                 .unwrap_or_default()