implement compare_vector util

diff --git a/src/bin/compare_vector.rs b/src/bin/compare_vector.rs
new file mode 100644 (file)
index 0000000..8e852ac
--- /dev/null
+++ b/src/bin/compare_vector.rs
@@ -0,0 +1,101 @@
+extern crate stud_rust_base;
+use stud_rust_base::io::*;
+use std::env;
+
+fn main() {
+    let mut args = env::args();
+    args.next();
+
+    match &args.collect::<Vec<String>>()[..] {
+        [data_type, input1, input2] => {
+            match data_type.as_ref() {
+                "i8" => compare_values(&Vec::<i8>::load_from(input1).expect("Failed to read from input1"), &Vec::<i8>::load_from(input2).expect("Failed to read from input2")),
+                "u8" => compare_values(&Vec::<u8>::load_from(input1).expect("Failed to read from input1"), &Vec::<u8>::load_from(input2).expect("Failed to read from input2")),
+                "i16" => compare_values(&Vec::<i16>::load_from(input1).expect("Failed to read from input1"), &Vec::<i16>::load_from(input2).expect("Failed to read from input2")),
+                "u16" => compare_values(&Vec::<u16>::load_from(input1).expect("Failed to read from input1"), &Vec::<u16>::load_from(input2).expect("Failed to read from input2")),
+                "i32" => compare_values(&Vec::<i32>::load_from(input1).expect("Failed to read from input1"), &Vec::<i32>::load_from(input2).expect("Failed to read from input2")),
+                "u32" => compare_values(&Vec::<u32>::load_from(input1).expect("Failed to read from input1"), &Vec::<u32>::load_from(input2).expect("Failed to read from input2")),
+                "i64" => compare_values(&Vec::<i64>::load_from(input1).expect("Failed to read from input1"), &Vec::<i64>::load_from(input2).expect("Failed to read from input2")),
+                "u64" => compare_values(&Vec::<u64>::load_from(input1).expect("Failed to read from input1"), &Vec::<u64>::load_from(input2).expect("Failed to read from input2")),
+                "f32" => compare_values(&Vec::<f32>::load_from(input1).expect("Failed to read from input1"), &Vec::<f32>::load_from(input2).expect("Failed to read from input2")),
+                "f64" => compare_values(&Vec::<f64>::load_from(input1).expect("Failed to read from input1"), &Vec::<f64>::load_from(input2).expect("Failed to read from input2")),
+                "int8" => compare_values(&Vec::<i8>::load_from(input1).expect("Failed to read from input1"), &Vec::<i8>::load_from(input2).expect("Failed to read from input2")),
+                "uint8" => compare_values(&Vec::<u8>::load_from(input1).expect("Failed to read from input1"), &Vec::<u8>::load_from(input2).expect("Failed to read from input2")),
+                "int16" => compare_values(&Vec::<i16>::load_from(input1).expect("Failed to read from input1"), &Vec::<i16>::load_from(input2).expect("Failed to read from input2")),
+                "uint16" => compare_values(&Vec::<u16>::load_from(input1).expect("Failed to read from input1"), &Vec::<u16>::load_from(input2).expect("Failed to read from input2")),
+                "int32" => compare_values(&Vec::<i32>::load_from(input1).expect("Failed to read from input1"), &Vec::<i32>::load_from(input2).expect("Failed to read from input2")),
+                "uint32" => compare_values(&Vec::<u32>::load_from(input1).expect("Failed to read from input1"), &Vec::<u32>::load_from(input2).expect("Failed to read from input2")),
+                "int64" => compare_values(&Vec::<i64>::load_from(input1).expect("Failed to read from input1"), &Vec::<i64>::load_from(input2).expect("Failed to read from input2")),
+                "uint64" => compare_values(&Vec::<u64>::load_from(input1).expect("Failed to read from input1"), &Vec::<u64>::load_from(input2).expect("Failed to read from input2")),
+                "float32" => compare_values(&Vec::<f32>::load_from(input1).expect("Failed to read from input1"), &Vec::<f32>::load_from(input2).expect("Failed to read from input2")),
+                "float64" => compare_values(&Vec::<f64>::load_from(input1).expect("Failed to read from input1"), &Vec::<f64>::load_from(input2).expect("Failed to read from input2")),
+                _ => {
+                    print_usage();
+                    panic!("Unknown data_type {}", data_type);
+                }
+            };
+        },
+        _ => {
+            print_usage();
+            panic!("Invalid input")
+        },
+    }
+}
+
+fn print_usage() {
+    eprintln!("Usage: decode_vector data_type vector1_file vector2_file
+
+Compares two vectors of elements in binary format. data_type can be one of
+* i8
+* u8
+* i16
+* u16
+* i32
+* u32
+* i64
+* u64
+* f32
+* f64
+
+");
+}
+
+use std::fmt::Display;
+
+fn compare_values<T>(values1: &[T], values2: &[T]) where
+    T: Display,
+    T: PartialOrd
+{
+    if values1.len() != values2.len() {
+        println!("Can only compare vectors of equal size. The first vector has {} elements. The second vector has {} elements.", values1.len(), values2.len());
+        return
+    }
+
+    let mut v1_smaller_count = 0;
+    let mut v2_smaller_count = 0;
+    let mut first_diff = None;
+
+    for (i, (v1, v2)) in values1.iter().zip(values2.iter()).enumerate() {
+        if v1 < v2 { v1_smaller_count += 1; }
+        if v2 < v1 { v2_smaller_count += 1; }
+
+        if first_diff.is_none() && v1 != v2 {
+            first_diff = Some(i)
+        }
+    }
+
+    match first_diff {
+        Some(index) => {
+            println!("The vectors differ.");
+            println!("{} elements are smaller in the first vector.", v1_smaller_count);
+            println!("{} elements are smaller in the second vector.", v2_smaller_count);
+            println!("{} elements are the same.", values1.len() - v1_smaller_count - v2_smaller_count);
+            println!("{} elements are different.", v1_smaller_count + v2_smaller_count);
+            println!("The vectors have  {} elements.", values1.len());
+            println!("The first element that differs is at index {}.", index);
+        },
+        None => {
+            println!("The vectors are the same and have  {} elements.", values1.len());
+        },
+    }
+}