Update README, slightly reduce code repetition

Cargo.lock

@@ -189,7 +189,7 @@ dependencies = [
 
 [[package]]
 name = "ouch"
-version = "0.1.1"
+version = "0.1.2"
 dependencies = [
  "bzip2 0.4.2",
  "clap",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ouch"
-version = "0.1.1"
+version = "0.1.2"
 authors = ["Vinícius Rodrigues Miguel <vrmiguel99@gmail.com>"]
 edition = "2018"
 readme = "README.md"

README.md

@@ -3,17 +3,17 @@
 `ouch` is the Obvious Unified Compression (and decompression) Helper. 
 
 
-| Supported formats | .tar | .zip | .tar.{.lz,.gz, .bz}          | .zip.{.lz, .gz, .bz, .bz2}   | .bz | .gz | .lz, .lzma |
+| Supported formats | .tar | .zip | .tar.{.lz*,.gz, .bz}         | .zip.{.lz*, .gz, .bz*}       | .bz | .gz | .lz, .lzma |
 |-------------------|------|------|------------------------------|------------------------------|-----|-----|------------|
 | Decompression     |   ✓  |   ✓  |               ✓              |               ✓              |  ✓  |  ✓  |      ✓     |
-| Compression       |   ✓  |   ✓  |               ✗              |               ✗              |  ✗  |  ✗  |      ✗     |
+| Compression       |   ✓  |   ✓  |               ✓              |               ✓              |  ✓  |  ✓  |      ✓     |
 
 ## How does it work?
 
 `ouch` infers commands from the extensions of its command-line options.
 
 ```
-ouch 0.1.1
+ouch 0.1.2
 Vinícius R. Miguel
 ouch is a unified compression & decompression utility
 

src/cli.rs

@@ -27,7 +27,7 @@ pub struct Command {
 
 pub fn clap_app<'a, 'b>() -> clap::App<'a, 'b> {
     clap::App::new("ouch")
-        .version("0.1.1")
+        .version("0.1.2")
         .about("ouch is a unified compression & decompression utility")
         .after_help(
 "ouch infers what to based on the extensions of the input files and output file received.

src/compressors/bzip.rs

@@ -3,7 +3,7 @@ use std::{fs, io::Write, path::PathBuf};
 use colored::Colorize;
 
 use crate::{error::{Error, OuchResult}, extension::CompressionFormat, file::File};
-use crate::utils::ensure_exists;
+use crate::utils::{ensure_exists, check_for_multiple_files};
 
 use super::{Compressor, Entry};
 
@@ -11,10 +11,7 @@ pub struct BzipCompressor {}
 
 impl BzipCompressor {
     fn compress_files(files: Vec<PathBuf>, format: CompressionFormat) -> OuchResult<Vec<u8>> {
-        if files.len() != 1 {
-            eprintln!("{}: cannot compress multiple files directly to {:#?}.\n     Try using an intermediate archival method such as Tar.\n     Example: filename.tar{}", "error".red(), format, format);
-            return Err(Error::InvalidInput);
-        }
+        check_for_multiple_files(&files, &format)?;
         let path = &files[0];
         ensure_exists(path)?;
         let contents = {

src/compressors/gzip.rs

@@ -2,8 +2,11 @@ use std::{fs, io::Write, path::PathBuf};
 
 use colored::Colorize;
 
-use crate::{error::{Error, OuchResult}, extension::CompressionFormat, file::File};
-use crate::utils::ensure_exists;
+use crate::{error::OuchResult, extension::CompressionFormat, file::File};
+use crate::utils::{
+    ensure_exists,
+    check_for_multiple_files
+};
 
 use super::{Compressor, Entry};
 
@@ -11,10 +14,7 @@ pub struct GzipCompressor {}
 
 impl GzipCompressor {
     pub fn compress_files(files: Vec<PathBuf>, format: CompressionFormat) -> OuchResult<Vec<u8>> {
-        if files.len() != 1 {
-            eprintln!("{}: cannot compress multiple files directly to {:#?}.\n     Try using an intermediate archival method such as Tar.\n     Example: filename.tar{}", "error".red(), format, format);
-            return Err(Error::InvalidInput);
-        }
+        check_for_multiple_files(&files, &format)?;
 
         let path = &files[0];
         ensure_exists(path)?;

src/compressors/lzma.rs

@@ -2,8 +2,11 @@ use std::{fs, io::Write, path::PathBuf};
 
 use colored::Colorize;
 
-use crate::{error::{Error, OuchResult}, extension::CompressionFormat, file::File};
-use crate::utils::ensure_exists;
+use crate::{error::{OuchResult}, extension::CompressionFormat, file::File};
+use crate::utils::{
+    ensure_exists,
+    check_for_multiple_files
+};
 
 use super::{Compressor, Entry};
 
@@ -11,10 +14,7 @@ pub struct LzmaCompressor {}
 
 impl LzmaCompressor {
     pub fn compress_files(files: Vec<PathBuf>, format: CompressionFormat) -> OuchResult<Vec<u8>> {
-        if files.len() != 1 {
-            eprintln!("{}: cannot compress multiple files directly to {:#?}.\n     Try using an intermediate archival method such as Tar.\n     Example: filename.tar{}", "error".red(), format, format);
-            return Err(Error::InvalidInput);
-        }
+        check_for_multiple_files(&files, &format)?;
 
         let path = &files[0];
         ensure_exists(path)?;

src/compressors/tar.rs

@@ -12,20 +12,10 @@ pub struct TarCompressor {}
 
 impl TarCompressor {
 
-    // TODO: this function does not seem to be working correctly ;/
-    fn make_archive_from_memory(input: File) -> OuchResult<Vec<u8>> {
-        
-        let _contents = match input.contents_in_memory {
-            Some(bytes) => bytes,
-            None => {
-                eprintln!("{}: reached TarCompressor::make_archive_from_memory without known content.", "internal error".red());
-                return Err(Error::InvalidInput);
-            }
-        };
-
-        println!("todo");
-
-        Ok(vec![])
+    // TODO: implement this
+    fn make_archive_from_memory(_input: File) -> OuchResult<Vec<u8>> {
+        println!("{}: .tar.tar and .zip.tar is currently unimplemented.", "error".red());
+        Err(Error::InvalidZipArchive(""))
     }
 
     fn make_archive_from_files(input_filenames: Vec<PathBuf>) -> OuchResult<Vec<u8>> {

src/error.rs

@@ -24,10 +24,6 @@ impl fmt::Display for Error {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 
         match self {
-            Error::InvalidInput => write!(
-                f,
-                "When `-o/--output` is omitted, all input files should be compressed files."
-            ),
             Error::MissingExtensionError(filename) => {
                 write!(f, "cannot compress to \'{}\', likely because it has an unsupported (or missing) extension.", filename)
             },
@@ -38,9 +34,9 @@ impl fmt::Display for Error {
             Error::FileNotFound => {
                 write!(f, "file not found!")
             }
-            err => {
+            _err => {
                 // TODO
-                write!(f, "todo: missing description for error {:?}", err)
+                write!(f, "")
             }
         }
     }

src/utils.rs

@@ -1,7 +1,7 @@
-use std::{fs, path::Path};
+use std::{fs, path::{Path, PathBuf}};
 
 use colored::Colorize;
-use crate::{error::OuchResult, file::File};
+use crate::{error::{Error, OuchResult}, extension::CompressionFormat, file::File};
 
 pub (crate) fn ensure_exists<'a, P>(path: P) -> OuchResult<()>
 where
@@ -13,6 +13,16 @@ where
         Ok(())
     }
 
+pub (crate) fn check_for_multiple_files(files: &Vec<PathBuf>, format: &CompressionFormat) -> OuchResult<()> {
+
+    if files.len() != 1 {
+        eprintln!("{}: cannot compress multiple files directly to {:#?}.\n       Try using an intermediate archival method such as Tar.\n       Example: filename.tar{}", "error".red(), format, format);
+        return Err(Error::InvalidInput);
+    }
+
+    Ok(())
+}
+
 pub (crate) fn create_path_if_non_existent(path: &Path) -> OuchResult<()> {
     if !path.exists() {
         println!(