Remove repeated Regex compilation

1 files changed, 13 insertions, 1 deletions

diff --git a/src/main.rs b/src/main.rs
index b3bdc29..d6c7c50 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,5 +1,7 @@
+use regex::Regex;
 use std::fs::File;
 use std::io::{self, BufRead, BufReader, Read, Write};
+use std::process;
 use structopt::StructOpt;
 
 mod choice;
@@ -18,12 +20,22 @@ fn main() {
     let lock = stdout.lock();
     let mut handle = io::BufWriter::new(lock);
 
+    let re = Regex::new(match &opt.field_separator {
+        Some(s) => s,
+        None => "[[:space:]]",
+    })
+    .unwrap_or_else(|e| {
+        eprintln!("Failed to compile regular expression: {}", e);
+        // Exit code of 1 means failed to compile field_separator regex
+        process::exit(1);
+    });
+
     let lines = buf.lines();
     for line in lines {
         match line {
             Ok(l) => {
                 for choice in &opt.choice {
-                    choice.print_choice(&l, &opt, &mut handle);
+                    choice.print_choice(&l, &opt, &re, &mut handle);
                 }
                 writeln!(handle, "");
             }