Add a feature to enable/disable serde integration

Author: htmlcsjs

Cargo.lock

@@ -7,5 +7,7 @@ default-run = "stoik"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-serde = { version = "1.0", features = ["derive"] }
-serde_json = "1.0"
+serde = { version = "1.0", features = ["derive"], optional = true }
+
+[features]
+serde = ["dep:serde"]

stoik/Cargo.toml

@@ -3,6 +3,7 @@ use std::{error::Error, fmt::Display};
 use crate::formula::{Molecule, SyntaxNode, TokenLoc};
 
 #[derive(Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 /// The error type for this crate
 pub enum StoikError {
     /// A token is in an invalid location

stoik/src/err.rs

@@ -21,13 +21,13 @@ use std::{
     fmt::{Debug, Display},
 };
 
-use serde::{Deserialize, Serialize};
 pub use tokenstream::*;
 
 use crate::err::StoikError;
 
 /// A node in a parsed chemical equation syntax tree
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub enum SyntaxNode {
     /// A subcompund, like the `(SO4)` in `Rh2(SO4)3`
     Subcompound(Vec<SyntaxNode>),
@@ -155,7 +155,8 @@ fn internal_tree(
     }
 }
 
-#[derive(Debug, Serialize, Deserialize, PartialEq, Eq, Clone)]
+#[derive(Debug, PartialEq, Eq, Clone)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 /// A repesentaion of a molecule used for stoichiometric puroposies
 ///
 /// # Examples

stoik/src/formula/mod.rs

@@ -122,6 +122,7 @@ impl<'a> TokenStream<'a> {
 }
 
 #[derive(Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 /// One "lexical" token in a formula. It carries along its location in a formula using [`TokenLoc`]
 /// This is intended to be generated with [`TokenStream`]
 pub enum Token {
@@ -197,6 +198,7 @@ impl Display for Token {
 }
 
 #[derive(Debug, Default, PartialEq, Eq)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 /// The location of one token in a formula. Used for debugging and error reporting
 ///
 /// # Examples