initial commit

.gitignore

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+/target
+**/*.rs.bk

Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "rust-fzf"
+version = "0.1.0"
+

Cargo.toml

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+[package]
+name = "rust-fzf"
+version = "0.1.0"
+authors = ["kageru <kageru@encode.moe>"]
+edition = "2018"
+
+[dependencies]

src/lib.rs

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+pub fn filter_substring<'a>(needle: &str, haystack: &Vec<&'a str>) -> Vec<&'a str> {
+    return haystack
+        .iter()
+        .filter(|s| s.contains(needle))
+        .cloned()
+        .collect();
+}
+
+pub fn filter_subsequence<'a>(needle: &str, haystack: &Vec<&'a str>) -> Vec<&'a str> {
+    return haystack
+        .iter()
+        .filter(|s| is_subsequence(needle, s))
+        .cloned()
+        .collect();
+}
+
+fn is_subsequence(needle: &str, string: &str) -> bool {
+    // we need to explicitly convert here to iterate over chars
+    // (UTF-8, so possibly multiple bytes long)
+    let mut chars = string.chars();
+    let needle_chars = needle.chars();
+    for nc in needle_chars {
+        loop {
+            match chars.next() {
+                Some(current) => {
+                    // if the character matches, break and continue with the next nc
+                    if current == nc {
+                        break;
+                    }
+                }
+                _ => return false
+            }
+        }
+    }
+    true
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{
+        filter_substring,
+        filter_subsequence
+    };
+
+    #[test]
+    fn test_filter_substring_single() {
+        let needle = "sdf";
+        let hay = vec!["asdf", "qwer"];
+        let expected = vec!["asdf"];
+        assert_eq!(filter_substring(&needle, &hay), expected);
+    }
+
+    #[test]
+    fn test_filter_substring_none() {
+        let needle = "sdf";
+        let hay = vec!["qwertz"];
+        let expected: Vec<&str> = Vec::new();
+        assert_eq!(filter_substring(&needle, &hay), expected);
+    }
+
+    #[test]
+    fn test_filter_substring_multiple() {
+        let needle = "sdf";
+        let hay = vec!["asdf", "asd", "sdfg", "dfgh"];
+        let expected = vec!["asdf", "sdfg"];
+        assert_eq!(filter_substring(&needle, &hay), expected);
+    }
+
+    #[test]
+    fn test_filter_subsequence_single() {
+        let needle = "asa";
+        let hay = vec!["aaass", "aasda"];
+        let expected = vec!["aasda"];
+        assert_eq!(filter_subsequence(&needle, &hay), expected);
+    }
+
+    #[test]
+    fn test_filter_subsequence_none() {
+        let needle = "asa";
+        let hay = vec!["aas"];
+        let expected: Vec<&str> = Vec::new();
+        assert_eq!(filter_subsequence(&needle, &hay), expected);
+    }
+
+    #[test]
+    fn test_filter_subsequence_multiple() {
+        let needle = "asa";
+        let hay = vec!["asa", "assa", "qwerafwfsferfssaas"];
+        assert_eq!(filter_subsequence(&needle, &hay), hay);
+    }
+}