feat: PromQL Rust Lexer

.gitignore

@@ -1,6 +1,7 @@
 # Generated by Cargo
 # will have compiled files and executables
 /target/
+.vscode
 
 # Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
 # More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html

examples/parser.rs

@@ -15,9 +15,10 @@
 use promql_parser::parser;
 
 fn main() {
-    let promql = "node_cpu_seconds_total{cpu=0,mode=idle}";
+    let promql = r#"prometheus_http_requests_total{code="200", job="prometheus"}"#;
 
-    let ast = parser::parse(promql).unwrap();
-
-    println!("AST: {:?}", ast);
+    match parser::parse(promql) {
+        Ok(ast) => println!("AST: {:?}", ast),
+        Err(info) => println!("Err: {:?}", info),
+    }
 }

src/label/matcher.rs

@@ -12,8 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use crate::parser::Token;
-use crate::parser::{T_EQL, T_EQL_REGEX, T_NEQ, T_NEQ_REGEX};
+use crate::parser::token::{Token, T_EQL, T_EQL_REGEX, T_NEQ, T_NEQ_REGEX};
 use regex::Regex;
 
 #[derive(Debug)]