Add grep example binary

Author: marmeladema

Cargo.toml

@@ -16,6 +16,7 @@ seq-macro = "0.2"
 
 [dev-dependencies]
 cfg-if = "1"
+memmap2 = "0.5"
 
 [profile.release]
 debug = true

examples/grep.rs

@@ -0,0 +1,57 @@
+use memmap2::MmapOptions;
+#[cfg(target_arch = "aarch64")]
+use sliceslice::aarch64::NeonSearcher;
+#[cfg(feature = "stdsimd")]
+use sliceslice::stdsimd::StdSimdSearcher;
+#[cfg(target_arch = "wasm32")]
+use sliceslice::wasm32::Wasm32Searcher;
+#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+use sliceslice::x86::{Avx2Searcher, DynamicAvx2Searcher};
+use std::fs::File;
+
+#[inline(never)]
+pub fn search_in_slice(backend: &str, needle: &[u8], haystack: &[u8]) -> bool {
+    #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+    if "avx2".eq_ignore_ascii_case(backend) {
+        let searcher = unsafe { Avx2Searcher::new(needle) };
+        return unsafe { searcher.search_in(haystack) };
+    }
+    #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+    if "dynamicavx2".eq_ignore_ascii_case(backend) {
+        let searcher = unsafe { DynamicAvx2Searcher::new(needle) };
+        return unsafe { searcher.search_in(haystack) };
+    }
+    #[cfg(any(target_arch = "aarch64"))]
+    if "neon".eq_ignore_ascii_case(backend) {
+        let searcher = unsafe { NeonSearcher::new(needle) };
+        return unsafe { searcher.search_in(haystack) };
+    }
+    #[cfg(feature = "stdsimd")]
+    if "stdsimd".eq_ignore_ascii_case(backend) {
+        let searcher = StdSimdSearcher::new(needle);
+        return searcher.search_in(haystack);
+    }
+    #[cfg(any(target_arch = "wasm32"))]
+    if "wasm32".eq_ignore_ascii_case(backend) {
+        let searcher = unsafe { Wasm32Searcher::new(needle) };
+        return unsafe { searcher.search_in(haystack) };
+    }
+    panic!("Invalid backend {:?}", backend);
+}
+
+fn main() {
+    let usage = "./grep <backend> <needle> <file>";
+    let mut args = std::env::args();
+    args.next().expect(usage);
+    let backend = args.next().expect(usage);
+    let needle = args.next().expect(usage);
+    let filename = args.next().expect(usage);
+    let file = File::open(&filename).unwrap();
+    let data = unsafe { MmapOptions::new().map(&file).unwrap() };
+    println!(
+        "Searching for {} in {:?}: {}",
+        needle,
+        filename,
+        search_in_slice(&backend, needle.as_bytes(), &data)
+    );
+}