Revert "refactor: Use nanorand crate instead of custom xorshift implementation"

This reverts commit d0ec00f.
I found that nanorand crate does not work on Mac OSX.

Author: Kogia-sima

Cargo.lock

@@ -28,8 +28,3 @@ optional = true
 
 [build-dependencies]
 version_check = "0.9.2"
-
-[dev-dependencies.nanorand]
-version = "0.5.1"
-default-features = false
-features = ["std", "wyrand"]

sailfish/Cargo.toml

@@ -106,7 +106,6 @@ pub fn escape_to_string(feed: &str, s: &mut String) {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use nanorand::RNG;
 
     fn escape(feed: &str) -> String {
         let mut s = String::new();
@@ -156,7 +155,7 @@ mod tests {
     #[test]
     fn random() {
         const ASCII_CHARS: &'static [u8] = br##"abcdefghijklmnopqrstuvwxyz0123456789-^\@[;:],./\!"#$%&'()~=~|`{+*}<>?_"##;
-        let mut gen = nanorand::WyRand::new();
+        let mut state = 88172645463325252u64;
         let mut data = Vec::with_capacity(100);
 
         let mut buf_naive = Buffer::new();
@@ -166,7 +165,12 @@ mod tests {
             for _ in 0..5 {
                 data.clear();
                 for _ in 0..len {
-                    let idx = gen.generate_range(0, ASCII_CHARS.len());
+                    // xorshift
+                    state ^= state << 13;
+                    state ^= state >> 7;
+                    state ^= state << 17;
+
+                    let idx = state as usize % ASCII_CHARS.len();
                     data.push(ASCII_CHARS[idx]);
                 }
 
@@ -180,6 +184,7 @@ mod tests {
                         s.as_ptr().add(s.len()),
                     );
 
+                    dbg!(s);
                     fallback::escape(s, &mut buf);
                     assert_eq!(buf.as_str(), buf_naive.as_str());
                     buf.clear();