Add rust lib for PURL validation using prebuilt FST

Signed-off-by: Keshav Priyadarshi <[email protected]>

Author: keshav-space

Cargo.toml

@@ -0,0 +1,28 @@
+[package]
+name = "purl_validator"
+version = "0.1.0"
+edition = "2024"
+authors = ["Keshav Priyadarshi <[email protected]>", "AboutCode <[email protected]>"]
+description = "PackageURL validator using prebuilt FST"
+license = "Apache-2.0"
+repository = "https://github.com/aboutcode-org/purl-validator"
+
+[lib]
+name = "purl_validator"
+crate-type = ["rlib"]
+
+[dependencies]
+fst = "0.4.7"
+once_cell = "1.21"
+
+[[bin]]
+name = "fst_builder"
+path = "fst_builder/main.rs"
+
+include = [
+    "src/**",
+    "purls.fst",
+    "Cargo.toml",
+    "README.md",
+    "LICENSE"
+]

purls.fst

@@ -0,0 +1,15 @@
+use fst::Set;
+use once_cell::sync::Lazy;
+
+
+static FST_BYTES: &[u8] = include_bytes!(concat!(env!("CARGO_MANIFEST_DIR"), "/purls.fst"));
+
+static VALIDATOR: Lazy<Set<&[u8]>> = Lazy::new(|| {
+    Set::new(FST_BYTES).expect("Failed to load FST from embedded bytes")
+});
+
+
+pub fn validate(word: &str) -> bool {
+    VALIDATOR.contains(word)
+}
+