Code review overhaul

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "json2rdf"
-version = "0.1.1"
+version = "0.2.0"
 authors = ["bharath181 <bharathselvaraj18@gmail.com>", "Greg Hanson <g.isaac.hanson@gmail.com>"]
 edition = "2021"
 license = "BSD-3-Clause OR Apache-2.0"
@@ -14,6 +14,7 @@ categories = ["command-line-utilities", "encoding", "parser-implementations", "s
 clap = { version = "4.6", features = ["derive"] }
 oxrdf = "0.3"
 serde_json = "1.0"
+thiserror = "2"
 
 [dev-dependencies]
 oxrdfio = "0.2"

Makefile

@@ -5,7 +5,7 @@
 # at your option.
 
 lint:
-	cargo install  cargo-machete
+	@command -v cargo-machete >/dev/null 2>&1 || cargo install cargo-machete
 	cargo fmt --check
 	cargo machete
 	cargo clippy --benches --tests --bins --no-deps --all-features

README.md

@@ -42,10 +42,13 @@ The conversion functionality can also be called directly in Rust. The library su
 use json2rdf::json_to_rdf;
 
 // capture conversion results to file
-let results = json_to_rdf(&"tests/airplane.json".to_string(), &Some("http://example.com/ns#".to_string()), &Some("output.nt".to_string()));
+let results = json_to_rdf(&["tests/airplane.json"], Some("http://example.com/ns#"), Some("output.nt"));
 
 // capture conversion results to an oxrdf::Graph
-let results = json_to_rdf(&"tests/airplane.json".to_string(), &Some("http://example.com/ns#".to_string()), &None);
+let results = json_to_rdf(&["tests/airplane.json"], Some("http://example.com/ns#"), None);
+
+// multiple input files are merged into a single graph
+let results = json_to_rdf(&["a.json", "b.json"], Some("http://example.com/ns#"), None);
 ```
 
 ## License