parse_line()

src/main.rs

@@ -1,3 +1,92 @@
+use std::fs::read_to_string;
+
+fn read_lines(filename: &str) -> Vec<String> {
+    let mut result: Vec<String> = Vec::new();
+
+    for line in read_to_string(filename).unwrap().lines() {
+        result.push(line.to_string())
+        // result.push(line);
+    }
+
+    result
+}
+
+fn parse_line(line: &str) -> i32 {
+    // Vec<&str>
+    let digits: [char; 10] = ['1', '2', '3', '4', '5', '6', '7', '8', '9', '0'];
+    // let s: String = String::from(line);
+    let mut f: String = String::from(line)
+        .chars()
+        .fold(String::new(), |mut acc, c| {
+            if digits.contains(&c) {
+                if acc.len() == 2 {
+                    acc.pop();
+                }
+                acc.push(c);
+            }
+            acc
+        });
+    if f.len() == 1 {
+        f.push_str(&(f.clone()));
+    }
+
+    let j: i32 = f.parse::<i32>().unwrap();
+    j
+}
+
 fn main() {
     println!("Hello, world!");
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::parse_line;
+
+    #[test]
+    fn test_parse_line_1() {
+        // arrange
+        let l: &str = "1abc2";
+
+        // act
+        let calib_val: i32 = parse_line(l);
+
+        // assert
+        assert_eq!(calib_val, 12);
+    }
+
+    #[test]
+    fn test_parse_line_2() {
+        // arrange
+        let l: &str = "pqr3stu8vwx";
+
+        // act
+        let calib_val: i32 = parse_line(l);
+
+        // assert
+        assert_eq!(calib_val, 38);
+    }
+
+    #[test]
+    fn test_parse_line_3() {
+        // arrange
+        let l: &str = "a1b2c3d4e5f";
+
+        // act
+        let calib_val: i32 = parse_line(l);
+
+        // assert
+        assert_eq!(calib_val, 15);
+    }
+
+    #[test]
+    fn test_parse_line_4() {
+        // arrange
+        let l: &str = "treb7uchet";
+
+        // act
+        let calib_val: i32 = parse_line(l);
+
+        // assert
+        assert_eq!(calib_val, 77);
+    }
+}