add wasm qr decode

deno_wasm_qr/decodeqr/src/lib.rs

@@ -0,0 +1,25 @@
+use std::ffi::CString;
+use std::os::raw::c_char;
+
+pub const SAMPLE_QR_BYTES: &[u8] = std::include_bytes!("sample_qr.png");
+
+#[no_mangle]
+pub extern "C" fn parse_default_qr() -> *mut c_char {
+    let s = CString::new(parse_qr()).unwrap();
+    s.into_raw()
+}
+
+pub fn parse_qr() -> String {
+    let img = image::load_from_memory(SAMPLE_QR_BYTES).unwrap();
+
+    let decoder = bardecoder::default_decoder();
+
+    let mut ret = vec![];
+    let results = decoder.decode(&img);
+    for result in results {
+        let qr = result.unwrap();
+        println!("{}", qr);
+        ret.push(qr);
+    }
+    ret.join(",")
+}