From 7928122fcef9ca7834d988b1ec8ca0687478beeb Mon Sep 17 00:00:00 2001
From: mokou <mokou@fastmail.com>
Date: Tue, 20 Apr 2021 12:46:49 +0200
Subject: [PATCH 1/3] feat: Replace clap with argh
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

I’ve been wanting to do this for a while, but always procrastinated on it. We’ve been using Clap since the 2.0 rewrite, but Clap is known to be a fairly heavy library. Since Rustlings is usually peoples’ first contact with a Rust compilation, I think it’s in our best interests that this complation is as fast as possible. In effect, replacing Clap with the smaller, structopt-style `argh` reduces the amount of crates needing to be compiled from 82 to 60.

I also think this makes the code way easier to read, we don’t need to use Clap’s methods anymore, but can switch over to using pure Rust methods, e.g., switches are booleans, options are Option<String>s or the like, and subcommands are just structs.
---
 Cargo.lock      | 543 +++++++++++++++++-------------------------------
 Cargo.toml      |   2 +-
 src/exercise.rs |   4 +-
 src/main.rs     | 411 ++++++++++++++++++------------------
 4 files changed, 395 insertions(+), 565 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 4a4313e7..367881c7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,22 +2,42 @@
 # It is not intended for manual editing.
 [[package]]
 name = "aho-corasick"
-version = "0.7.3"
+version = "0.7.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6f484ae0c99fec2e858eb6134949117399f222608d84cadb3f58c1f97c2364c"
+checksum = "7404febffaa47dac81aa44dba71523c9d069b1bdc50a77db41195149e17f68e5"
 dependencies = [
  "memchr",
 ]
 
 [[package]]
-name = "ansi_term"
-version = "0.11.0"
+name = "argh"
+version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
+checksum = "91792f088f87cdc7a2cfb1d617fa5ea18d7f1dc22ef0e1b5f82f3157cdc522be"
 dependencies = [
- "winapi 0.3.8",
+ "argh_derive",
+ "argh_shared",
 ]
 
+[[package]]
+name = "argh_derive"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4eb0c0c120ad477412dc95a4ce31e38f2113e46bd13511253f79196ca68b067"
+dependencies = [
+ "argh_shared",
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "argh_shared"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "781f336cc9826dbaddb9754cb5db61e64cab4f69668bd19dcc4a0394a86f4cb1"
+
 [[package]]
 name = "assert_cmd"
 version = "0.11.1"
@@ -32,67 +52,49 @@ dependencies = [
 
 [[package]]
 name = "atty"
-version = "0.2.11"
+version = "0.2.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9a7d5b8723950951411ee34d271d99dddcc2035a16ab25310ea2c8cfd4369652"
+checksum = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
 dependencies = [
+ "hermit-abi",
  "libc",
- "termion",
- "winapi 0.3.8",
+ "winapi 0.3.9",
 ]
 
 [[package]]
 name = "autocfg"
-version = "0.1.4"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0e49efa51329a5fd37e7c79db4621af617cd4e3e5bc224939808d076077077bf"
+checksum = "cdb031dd78e28731d87d56cc8ffef4a8f36ca26c38fe2de700543e627f8a464a"
 
 [[package]]
 name = "bitflags"
-version = "1.0.4"
+version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "228047a76f468627ca71776ecdebd732a3423081fcf5125585bcd7c49886ce12"
+checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
 
 [[package]]
 name = "cfg-if"
-version = "0.1.9"
+version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b486ce3ccf7ffd79fdeb678eac06a9e6c09fc88d33836340becb8fffe87c5e33"
+checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 
 [[package]]
-name = "clap"
-version = "2.33.0"
+name = "cfg-if"
+version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5067f5bb2d80ef5d68b4c87db81601f0b75bca627bc2ef76b141d7b846a3c6d9"
-dependencies = [
- "ansi_term",
- "atty",
- "bitflags",
- "strsim",
- "textwrap",
- "unicode-width",
- "vec_map",
-]
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
 name = "clicolors-control"
-version = "1.0.0"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "73abfd4c73d003a674ce5d2933fca6ce6c42480ea84a5ffe0a2dc39ed56300f9"
+checksum = "90082ee5dcdd64dc4e9e0d37fbf3ee325419e39c0092191e0393df65518f741e"
 dependencies = [
  "atty",
  "lazy_static",
  "libc",
- "winapi 0.3.8",
-]
-
-[[package]]
-name = "cloudabi"
-version = "0.0.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
-dependencies = [
- "bitflags",
+ "winapi 0.3.9",
 ]
 
 [[package]]
@@ -110,23 +112,22 @@ dependencies = [
  "regex",
  "termios",
  "unicode-width",
- "winapi 0.3.8",
+ "winapi 0.3.9",
 ]
 
 [[package]]
 name = "console"
-version = "0.8.0"
+version = "0.14.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b147390a412132d75d10dd3b7b175a69cf5fd95032f7503c7091b8831ba10242"
+checksum = "3993e6445baa160675931ec041a5e03ca84b9c6e32a056150d3aa2bdda0a1f45"
 dependencies = [
- "clicolors-control",
  "encode_unicode",
  "lazy_static",
  "libc",
  "regex",
- "termios",
+ "terminal_size",
  "unicode-width",
- "winapi 0.3.8",
+ "winapi 0.3.9",
 ]
 
 [[package]]
@@ -137,9 +138,9 @@ checksum = "524cbf6897b527295dff137cec09ecf3a05f4fddffd7dfcd1585403449e74198"
 
 [[package]]
 name = "encode_unicode"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90b2c9496c001e8cb61827acdefad780795c42264c137744cae6f7d9e3450abd"
+checksum = "a357d28ed41a50f9c765dbfe56cbc04a64e53e5fc58ba79fbc34c10ef3df831f"
 
 [[package]]
 name = "escargot"
@@ -155,20 +156,21 @@ dependencies = [
 
 [[package]]
 name = "filetime"
-version = "0.2.5"
+version = "0.2.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2f8c63033fcba1f51ef744505b3cad42510432b904c062afa67ad7ece008429d"
+checksum = "1d34cfa13a63ae058bfa601fe9e313bbdb3746427c1459185464ce0fcf62e1e8"
 dependencies = [
- "cfg-if",
+ "cfg-if 1.0.0",
  "libc",
  "redox_syscall",
+ "winapi 0.3.9",
 ]
 
 [[package]]
 name = "float-cmp"
-version = "0.4.0"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "134a8fa843d80a51a5b77d36d42bc2def9edcb0262c914861d08129fd1926600"
+checksum = "e1267f4ac4f343772758f7b1bdcbe767c218bbab93bb432acbf5162bbf85a6c4"
 dependencies = [
  "num-traits",
 ]
@@ -192,12 +194,6 @@ dependencies = [
  "libc",
 ]
 
-[[package]]
-name = "fuchsia-cprng"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
-
 [[package]]
 name = "fuchsia-zircon"
 version = "0.3.3"
@@ -220,13 +216,31 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9b919933a397b79c37e33b77bb2aa3dc8eb6e165ad809e58ff75bc7db2e34574"
 
+[[package]]
+name = "heck"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "87cbf45460356b7deeb5e3415b5563308c0a9b057c85e12b06ad551f98d0a6ac"
+dependencies = [
+ "unicode-segmentation",
+]
+
+[[package]]
+name = "hermit-abi"
+version = "0.1.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "322f4de77956e22ed0e5032c359a0f1273f1f7f0d79bfa3b8ffbc730d7fbcc5c"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "indicatif"
 version = "0.10.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "40ecd1e2ee08e6c255ce890f5a99d17000850e664e7acf119fb03b25b0575bfe"
 dependencies = [
- "console 0.8.0",
+ "console 0.14.1",
  "lazy_static",
  "number_prefix",
  "parking_lot",
@@ -235,9 +249,9 @@ dependencies = [
 
 [[package]]
 name = "inotify"
-version = "0.7.0"
+version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "24e40d6fd5d64e2082e0c796495c8ef5ad667a96d03e5aaa0becfd9d47bcbfb8"
+checksum = "4816c66d2c8ae673df83366c18341538f234a26d65a9ecea5c348b453ac1d02f"
 dependencies = [
  "bitflags",
  "inotify-sys",
@@ -246,28 +260,36 @@ dependencies = [
 
 [[package]]
 name = "inotify-sys"
-version = "0.1.3"
+version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e74a1aa87c59aeff6ef2cc2fa62d41bc43f54952f55652656b18a02fd5e356c0"
+checksum = "e05c02b5e89bff3b946cedeca278abc628fe811e604f027c45a8aa3cf793d0eb"
 dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "instant"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "61124eeebbd69b8190558df225adf7e4caafce0d743919e5d6b19652314ec5ec"
+dependencies = [
+ "cfg-if 1.0.0",
+]
+
 [[package]]
 name = "iovec"
-version = "0.1.2"
+version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dbe6e417e7d0975db6512b90796e8ce223145ac4e33c377e4a42882a0e88bb08"
+checksum = "b2b3ea6ff95e175473f8ffe6a7eb7c00d054240321b84c57051175fe3c1e075e"
 dependencies = [
  "libc",
- "winapi 0.2.8",
 ]
 
 [[package]]
 name = "itoa"
-version = "0.4.4"
+version = "0.4.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "501266b7edd0174f8530248f87f99c88fbe60ca4ef3dd486835b8d8d53136f7f"
+checksum = "dd25036021b0de88a0aff6b850051563c6516d0bf53f8638938edbb9de732736"
 
 [[package]]
 name = "kernel32-sys"
@@ -281,52 +303,53 @@ dependencies = [
 
 [[package]]
 name = "lazy_static"
-version = "1.3.0"
+version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bc5729f27f159ddd61f4df6228e827e86643d4d3e7c32183cb30a1c08f604a14"
+checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "lazycell"
-version = "1.2.1"
+version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f"
+checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
 
 [[package]]
 name = "libc"
-version = "0.2.58"
+version = "0.2.93"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6281b86796ba5e4366000be6e9e18bf35580adf9e63fbe2294aadb587613a319"
+checksum = "9385f66bf6105b241aa65a61cb923ef20efc665cb9f9bb50ac2f0c4b7f378d41"
 
 [[package]]
 name = "lock_api"
-version = "0.2.0"
+version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed946d4529956a20f2d63ebe1b69996d5a2137c91913fe3ebbeff957f5bca7ff"
+checksum = "5a3c91c24eae6777794bb1997ad98bbb87daf92890acab859f7eaa4320333176"
 dependencies = [
  "scopeguard",
 ]
 
 [[package]]
 name = "log"
-version = "0.4.6"
+version = "0.4.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c84ec4b527950aa83a329754b01dbe3f58361d1c5efacd1f6d68c494d08a17c6"
+checksum = "51b9bbe6c47d51fc3e1a9b945965946b4c44142ab8792c50835a980d362c2710"
 dependencies = [
- "cfg-if",
+ "cfg-if 1.0.0",
 ]
 
 [[package]]
 name = "memchr"
-version = "2.2.0"
+version = "2.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2efc7bc57c883d4a4d6e3246905283d8dae951bb3bd32f49d6ef297f546e1c39"
+checksum = "0ee1c47aaa256ecabcaea351eae4a9b01ef39ed810004e298d2511ed284b1525"
 
 [[package]]
 name = "mio"
-version = "0.6.19"
+version = "0.6.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "83f51996a3ed004ef184e16818edc51fadffe8e7ca68be67f9dee67d84d0ff23"
+checksum = "4afd66f5b91bf2a3bc13fad0e21caedac168ca4c707504e75585648ae80e4cc4"
 dependencies = [
+ "cfg-if 0.1.10",
  "fuchsia-zircon",
  "fuchsia-zircon-sys",
  "iovec",
@@ -341,9 +364,9 @@ dependencies = [
 
 [[package]]
 name = "mio-extras"
-version = "2.0.5"
+version = "2.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46e73a04c2fa6250b8d802134d56d554a9ec2922bf977777c805ea5def61ce40"
+checksum = "52403fe290012ce777c4626790c8951324a2b9e3316b3143779c72b029742f19"
 dependencies = [
  "lazycell",
  "log",
@@ -353,9 +376,9 @@ dependencies = [
 
 [[package]]
 name = "miow"
-version = "0.2.1"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8c1f2f3b1cf331de6896aabf6e9d55dca90356cc9960cca7eaaf408a355ae919"
+checksum = "ebd808424166322d4a38da87083bfddd3ac4c131334ed55856112eb06d46944d"
 dependencies = [
  "kernel32-sys",
  "net2",
@@ -365,26 +388,26 @@ dependencies = [
 
 [[package]]
 name = "net2"
-version = "0.2.33"
+version = "0.2.37"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "42550d9fb7b6684a6d404d9fa7250c2eb2646df731d1c06afc06dcee9e1bcf88"
+checksum = "391630d12b68002ae1e25e8f974306474966550ad82dac6886fb8910c19568ae"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "libc",
- "winapi 0.3.8",
+ "winapi 0.3.9",
 ]
 
 [[package]]
 name = "normalize-line-endings"
-version = "0.2.2"
+version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2e0a1a39eab95caf4f5556da9289b9e68f0aafac901b2ce80daaf020d3b733a8"
+checksum = "61807f77802ff30975e01f4f071c8ba10c022052f98b3294119f3e615d13e5be"
 
 [[package]]
 name = "notify"
-version = "4.0.15"
+version = "4.0.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "80ae4a7688d1fab81c5bf19c64fc8db920be8d519ce6336ed4e7efe024724dbd"
+checksum = "2599080e87c9bd051ddb11b10074f4da7b1223298df65d4c2ec5bcf309af1533"
 dependencies = [
  "bitflags",
  "filetime",
@@ -395,14 +418,14 @@ dependencies = [
  "mio",
  "mio-extras",
  "walkdir",
- "winapi 0.3.8",
+ "winapi 0.3.9",
 ]
 
 [[package]]
 name = "num-traits"
-version = "0.2.8"
+version = "0.2.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6ba9a427cfca2be13aa6f6403b0b7e7368fe982bfa16fccc450ce74c46cd9b32"
+checksum = "9a64b1ec5cda2586e284722486d802acf1f7dbdc623e2bfc57e65ca1cd099290"
 dependencies = [
  "autocfg",
 ]
@@ -416,44 +439,36 @@ dependencies = [
  "num-traits",
 ]
 
-[[package]]
-name = "numtoa"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b8f8bdf33df195859076e54ab11ee78a1b208382d3a26ec40d142ffc1ecc49ef"
-
 [[package]]
 name = "parking_lot"
-version = "0.8.0"
+version = "0.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa7767817701cce701d5585b9c4db3cdd02086398322c1d7e8bf5094a96a2ce7"
+checksum = "6d7744ac029df22dca6284efe4e898991d28e3085c706c972bcd7da4a27a15eb"
 dependencies = [
+ "instant",
  "lock_api",
  "parking_lot_core",
- "rustc_version",
 ]
 
 [[package]]
 name = "parking_lot_core"
-version = "0.5.0"
+version = "0.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cb88cb1cb3790baa6776844f968fea3be44956cf184fa1be5a03341f5491278c"
+checksum = "fa7a782938e745763fe6907fc6ba86946d72f49fe7e21de074e08128a99fb018"
 dependencies = [
- "cfg-if",
- "cloudabi",
+ "cfg-if 1.0.0",
+ "instant",
  "libc",
- "rand",
  "redox_syscall",
- "rustc_version",
  "smallvec",
- "winapi 0.3.8",
+ "winapi 0.3.9",
 ]
 
 [[package]]
 name = "predicates"
-version = "1.0.1"
+version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "53e09015b0d3f5a0ec2d4428f7559bb7b3fff341b4e159fedd1d57fac8b939ff"
+checksum = "eeb433456c1a57cc93554dea3ce40b4c19c4057e41c55d4a0f3d84ea71c325aa"
 dependencies = [
  "difference",
  "float-cmp",
@@ -464,15 +479,15 @@ dependencies = [
 
 [[package]]
 name = "predicates-core"
-version = "1.0.0"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "06075c3a3e92559ff8929e7a280684489ea27fe44805174c3ebd9328dcb37178"
+checksum = "57e35a3326b75e49aa85f5dc6ec15b41108cf5aee58eabb1f274dd18b73c2451"
 
 [[package]]
 name = "predicates-tree"
-version = "1.0.0"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e63c4859013b38a76eca2414c64911fba30def9e3202ac461a2d22831220124"
+checksum = "15f553275e5721409451eb85e15fd9a860a6e5ab4496eb215987502b5f5391f2"
 dependencies = [
  "predicates-core",
  "treeline",
@@ -480,189 +495,54 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "0.4.30"
+version = "1.0.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cf3d2011ab5c909338f7887f4fc896d35932e29146c12c8d01da6b22a80ba759"
+checksum = "a152013215dca273577e18d2bf00fa862b89b24169fb78c4c95aeb07992c9cec"
 dependencies = [
  "unicode-xid",
 ]
 
 [[package]]
 name = "quote"
-version = "0.6.12"
+version = "1.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "faf4799c5d274f3868a4aae320a0a182cbd2baee377b378f080e16a23e9d80db"
+checksum = "c3d0b9745dc2debf507c8422de05d7226cc1f0644216dfdfead988f9b1ab32a7"
 dependencies = [
  "proc-macro2",
 ]
 
-[[package]]
-name = "rand"
-version = "0.6.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6d71dacdc3c88c1fde3885a3be3fbab9f35724e6ce99467f7d9c5026132184ca"
-dependencies = [
- "autocfg",
- "libc",
- "rand_chacha",
- "rand_core 0.4.0",
- "rand_hc",
- "rand_isaac",
- "rand_jitter",
- "rand_os",
- "rand_pcg",
- "rand_xorshift",
- "winapi 0.3.8",
-]
-
-[[package]]
-name = "rand_chacha"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "556d3a1ca6600bfcbab7c7c91ccb085ac7fbbcd70e008a98742e7847f4f7bcef"
-dependencies = [
- "autocfg",
- "rand_core 0.3.1",
-]
-
-[[package]]
-name = "rand_core"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a6fdeb83b075e8266dcc8762c22776f6877a63111121f5f8c7411e5be7eed4b"
-dependencies = [
- "rand_core 0.4.0",
-]
-
-[[package]]
-name = "rand_core"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d0e7a549d590831370895ab7ba4ea0c1b6b011d106b5ff2da6eee112615e6dc0"
-
-[[package]]
-name = "rand_hc"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7b40677c7be09ae76218dc623efbf7b18e34bced3f38883af07bb75630a21bc4"
-dependencies = [
- "rand_core 0.3.1",
-]
-
-[[package]]
-name = "rand_isaac"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ded997c9d5f13925be2a6fd7e66bf1872597f759fd9dd93513dd7e92e5a5ee08"
-dependencies = [
- "rand_core 0.3.1",
-]
-
-[[package]]
-name = "rand_jitter"
-version = "0.1.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1166d5c91dc97b88d1decc3285bb0a99ed84b05cfd0bc2341bdf2d43fc41e39b"
-dependencies = [
- "libc",
- "rand_core 0.4.0",
- "winapi 0.3.8",
-]
-
-[[package]]
-name = "rand_os"
-version = "0.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7b75f676a1e053fc562eafbb47838d67c84801e38fc1ba459e8f180deabd5071"
-dependencies = [
- "cloudabi",
- "fuchsia-cprng",
- "libc",
- "rand_core 0.4.0",
- "rdrand",
- "winapi 0.3.8",
-]
-
-[[package]]
-name = "rand_pcg"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "abf9b09b01790cfe0364f52bf32995ea3c39f4d2dd011eac241d2914146d0b44"
-dependencies = [
- "autocfg",
- "rand_core 0.4.0",
-]
-
-[[package]]
-name = "rand_xorshift"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cbf7e9e623549b0e21f6e97cf8ecf247c1a8fd2e8a992ae265314300b2455d5c"
-dependencies = [
- "rand_core 0.3.1",
-]
-
-[[package]]
-name = "rdrand"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "678054eb77286b51581ba43620cc911abf02758c91f93f479767aed0f90458b2"
-dependencies = [
- "rand_core 0.3.1",
-]
-
 [[package]]
 name = "redox_syscall"
-version = "0.1.54"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "12229c14a0f65c4f1cb046a3b52047cdd9da1f4b30f8a39c5063c8bae515e252"
-
-[[package]]
-name = "redox_termios"
-version = "0.1.1"
+version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7e891cfe48e9100a70a3b6eb652fef28920c117d366339687bd5576160db0f76"
+checksum = "8270314b5ccceb518e7e578952f0b72b88222d02e8f77f5ecf7abbb673539041"
 dependencies = [
- "redox_syscall",
+ "bitflags",
 ]
 
 [[package]]
 name = "regex"
-version = "1.1.6"
+version = "1.4.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8f0a0bcab2fd7d1d7c54fa9eae6f43eddeb9ce2e7352f8518a814a4f65d60c58"
+checksum = "957056ecddbeba1b26965114e191d2e8589ce74db242b6ea25fc4062427a5c19"
 dependencies = [
  "aho-corasick",
  "memchr",
  "regex-syntax",
- "thread_local",
- "utf8-ranges",
 ]
 
 [[package]]
 name = "regex-syntax"
-version = "0.6.6"
+version = "0.6.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dcfd8681eebe297b81d98498869d4aae052137651ad7b96822f09ceb690d0a96"
-dependencies = [
- "ucd-util",
-]
-
-[[package]]
-name = "rustc_version"
-version = "0.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
-dependencies = [
- "semver",
-]
+checksum = "24d5f089152e60f62d28b835fbff2cd2e8dc0baf1ac13343bef92ab7eed84548"
 
 [[package]]
 name = "rustlings"
 version = "4.3.0"
 dependencies = [
+ "argh",
  "assert_cmd",
- "clap",
  "console 0.7.7",
  "glob",
  "indicatif",
@@ -675,54 +555,39 @@ dependencies = [
 
 [[package]]
 name = "ryu"
-version = "0.2.8"
+version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b96a9549dc8d48f2c283938303c4b5a77aa29bfbc5b54b084fb1630408899a8f"
+checksum = "71d301d4193d031abdd79ff7e3dd721168a9572ef3fe51a1517aba235bd8f86e"
 
 [[package]]
 name = "same-file"
-version = "1.0.4"
+version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8f20c4be53a8a1ff4c1f1b2bd14570d2f634628709752f0702ecdd2b3f9a5267"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
 dependencies = [
  "winapi-util",
 ]
 
 [[package]]
 name = "scopeguard"
-version = "1.0.0"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b42e15e59b18a828bbf5c58ea01debb36b9b096346de35d941dcb89009f24a0d"
-
-[[package]]
-name = "semver"
-version = "0.9.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
-dependencies = [
- "semver-parser",
-]
-
-[[package]]
-name = "semver-parser"
-version = "0.7.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
+checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
 [[package]]
 name = "serde"
-version = "1.0.92"
+version = "1.0.125"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32746bf0f26eab52f06af0d0aa1984f641341d06d8d673c693871da2d188c9be"
+checksum = "558dc50e1a5a5fa7112ca2ce4effcb321b0300c0d4ccf0776a9f60cd89031171"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.92"
+version = "1.0.125"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46a3223d0c9ba936b61c0d2e3e559e3217dbfb8d65d06d26e8b3c25de38bae3e"
+checksum = "b093b7a2bb58203b5da3056c05b4ec1fed827dcfdb37347a8841695263b3d06d"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -731,9 +596,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.39"
+version = "1.0.64"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a23aa71d4a4d43fdbfaac00eff68ba8a06a51759a89ac3304323e800c4dd40d"
+checksum = "799e97dc9fdae36a5c8b8f2cae9ce2ee9fdce2058c57a93e6099d919fd982f79"
 dependencies = [
  "itoa",
  "ryu",
@@ -748,21 +613,15 @@ checksum = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
 
 [[package]]
 name = "smallvec"
-version = "0.6.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c4488ae950c49d403731982257768f48fada354a5203fe81f9bb6f43ca9002be"
-
-[[package]]
-name = "strsim"
-version = "0.8.0"
+version = "1.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
+checksum = "fe0f37c9e8f3c5a4a66ad655a93c74daac4ad00c441533bf5c6e7990bb42604e"
 
 [[package]]
 name = "syn"
-version = "0.15.34"
+version = "1.0.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a1393e4a97a19c01e900df2aec855a29f71cf02c402e2f443b8d2747c25c5dbe"
+checksum = "48fe99c6bd8b1cc636890bcc071842de909d902c81ac7dab53ba33c421ab8ffb"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -770,44 +629,24 @@ dependencies = [
 ]
 
 [[package]]
-name = "termion"
-version = "1.5.2"
+name = "terminal_size"
+version = "0.1.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dde0593aeb8d47accea5392b39350015b5eccb12c0d98044d856983d89548dea"
+checksum = "86ca8ced750734db02076f44132d802af0b33b09942331f4459dde8636fd2406"
 dependencies = [
  "libc",
- "numtoa",
- "redox_syscall",
- "redox_termios",
+ "winapi 0.3.9",
 ]
 
 [[package]]
 name = "termios"
-version = "0.3.1"
+version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "72b620c5ea021d75a735c943269bb07d30c9b77d6ac6b236bc8b5c496ef05625"
+checksum = "411c5bf740737c7918b8b1fe232dca4dc9f8e754b8ad5e20966814001ed0ac6b"
 dependencies = [
  "libc",
 ]
 
-[[package]]
-name = "textwrap"
-version = "0.11.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d326610f408c7a4eb6f51c37c330e496b08506c9457c9d34287ecc38809fb060"
-dependencies = [
- "unicode-width",
-]
-
-[[package]]
-name = "thread_local"
-version = "0.3.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c6b53e329000edc2b34dbe8545fd20e55a333362d0a321909685a19bd28c3f1b"
-dependencies = [
- "lazy_static",
-]
-
 [[package]]
 name = "toml"
 version = "0.4.10"
@@ -824,43 +663,31 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a7f741b240f1a48843f9b8e0444fb55fb2a4ff67293b50a9179dfd5ea67f8d41"
 
 [[package]]
-name = "ucd-util"
-version = "0.1.3"
+name = "unicode-segmentation"
+version = "1.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "535c204ee4d8434478593480b8f86ab45ec9aae0e83c568ca81abf0fd0e88f86"
+checksum = "bb0d2e7be6ae3a5fa87eed5fb451aff96f2573d2694942e40543ae0bbe19c796"
 
 [[package]]
 name = "unicode-width"
-version = "0.1.5"
+version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "882386231c45df4700b275c7ff55b6f3698780a650026380e72dabe76fa46526"
+checksum = "9337591893a19b88d8d87f2cec1e73fad5cdfd10e5a6f349f498ad6ea2ffb1e3"
 
 [[package]]
 name = "unicode-xid"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fc72304796d0818e357ead4e000d19c9c174ab23dc11093ac919054d20a6a7fc"
-
-[[package]]
-name = "utf8-ranges"
-version = "1.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "796f7e48bef87609f7ade7e06495a87d5cd06c7866e6a5cbfceffc558a243737"
-
-[[package]]
-name = "vec_map"
-version = "0.8.1"
+version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "05c78687fb1a80548ae3250346c3db86a80a7cdd77bda190189f2d0a0987c81a"
+checksum = "f7fe0bb3479651439c9112f72b6c505038574c9fbb575ed1bf3b797fa39dd564"
 
 [[package]]
 name = "walkdir"
-version = "2.2.7"
+version = "2.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9d9d7ed3431229a144296213105a390676cc49c9b6a72bd19f3176c98e129fa1"
+checksum = "808cf2735cd4b6866113f648b791c6adc5714537bc222d9347bb203386ffda56"
 dependencies = [
  "same-file",
- "winapi 0.3.8",
+ "winapi 0.3.9",
  "winapi-util",
 ]
 
@@ -872,9 +699,9 @@ checksum = "167dc9d6949a9b857f3451275e911c3f44255842c1f7a76f33c55103a909087a"
 
 [[package]]
 name = "winapi"
-version = "0.3.8"
+version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8093091eeb260906a183e6ae1abdba2ef5ef2257a21801128899c3fc699229c6"
+checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
 dependencies = [
  "winapi-i686-pc-windows-gnu",
  "winapi-x86_64-pc-windows-gnu",
@@ -894,11 +721,11 @@ checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 
 [[package]]
 name = "winapi-util"
-version = "0.1.2"
+version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7168bab6e1daee33b4557efd0e95d5ca70a03706d39fa5f3fe7a236f584b03c9"
+checksum = "70ec6ce85bb158151cae5e5c87f95a8e97d2c0c4b001223f33a334e3ce5de178"
 dependencies = [
- "winapi 0.3.8",
+ "winapi 0.3.9",
 ]
 
 [[package]]
diff --git a/Cargo.toml b/Cargo.toml
index a0564c37..397eb996 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,7 +5,7 @@ authors = ["Marisa <mokou@posteo.de>", "Carol (Nichols || Goulding) <carol.nicho
 edition = "2018"
 
 [dependencies]
-clap = "2.32.0"
+argh = "0.1.4"
 indicatif = "0.10.3"
 console = "0.7.7"
 notify = "4.0.15"
diff --git a/src/exercise.rs b/src/exercise.rs
index e9d1c1c9..d934cfd3 100644
--- a/src/exercise.rs
+++ b/src/exercise.rs
@@ -24,7 +24,7 @@ fn temp_file() -> String {
 }
 
 // The mode of the exercise.
-#[derive(Deserialize, Copy, Clone)]
+#[derive(Deserialize, Copy, Clone, Debug)]
 #[serde(rename_all = "lowercase")]
 pub enum Mode {
     // Indicates that the exercise should be compiled as a binary
@@ -42,7 +42,7 @@ pub struct ExerciseList {
 
 // A representation of a rustlings exercise.
 // This is deserialized from the accompanying info.toml file
-#[derive(Deserialize)]
+#[derive(Deserialize, Debug)]
 pub struct Exercise {
     // Name of the exercise
     pub name: String,
diff --git a/src/main.rs b/src/main.rs
index 3b7a1942..5af5febc 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,7 +1,7 @@
 use crate::exercise::{Exercise, ExerciseList};
 use crate::run::run;
 use crate::verify::verify;
-use clap::{crate_version, App, Arg, SubCommand};
+use argh::FromArgs;
 use console::Emoji;
 use notify::DebouncedEvent;
 use notify::{RecommendedWatcher, RecursiveMode, Watcher};
@@ -22,85 +22,91 @@ mod exercise;
 mod run;
 mod verify;
 
+// In sync with crate version
+const VERSION: &str = "4.3.0";
+
+#[derive(FromArgs, PartialEq, Debug)]
+/// Rustlings is a collection of small exercises to get you used to writing and reading Rust code
+struct Args {
+    /// show outputs from the test exercises
+    #[argh(switch)]
+    nocapture: bool,
+    /// show the executable version
+    #[argh(switch, short = 'v')]
+    version: bool,
+    #[argh(subcommand)]
+    nested: Option<Subcommands>,
+}
+
+#[derive(FromArgs, PartialEq, Debug)]
+#[argh(subcommand)]
+enum Subcommands {
+    Verify(VerifyArgs),
+    Watch(WatchArgs),
+    Run(RunArgs),
+    Hint(HintArgs),
+    List(ListArgs),
+}
+
+#[derive(FromArgs, PartialEq, Debug)]
+#[argh(subcommand, name = "verify")]
+/// Verifies all exercises according to the recommended order
+struct VerifyArgs {}
+
+#[derive(FromArgs, PartialEq, Debug)]
+#[argh(subcommand, name = "watch")]
+/// Reruns `verify` when files were edited
+struct WatchArgs {}
+
+#[derive(FromArgs, PartialEq, Debug)]
+#[argh(subcommand, name = "run")]
+/// Runs/Tests a single exercise
+struct RunArgs {
+    #[argh(positional)]
+    /// the name of the exercise
+    name: String,
+}
+
+#[derive(FromArgs, PartialEq, Debug)]
+#[argh(subcommand, name = "hint")]
+/// Returns a hint for the given exercise
+struct HintArgs {
+    #[argh(positional)]
+    /// the name of the exercise
+    name: String,
+}
+
+#[derive(FromArgs, PartialEq, Debug)]
+#[argh(subcommand, name = "list")]
+/// Lists the exercises available in Rustlings
+struct ListArgs {
+    #[argh(switch, short = 'p')]
+    /// show only the paths of the exercises
+    paths: bool,
+    #[argh(switch, short = 'n')]
+    /// show only the names of the exercises
+    names: bool,
+    #[argh(option, short = 'f')]
+    /// provide a string to match exercise names
+    /// comma separated patterns are acceptable
+    filter: Option<String>,
+    #[argh(switch, short = 'u')]
+    /// display only exercises not yet solved
+    unsolved: bool,
+    #[argh(switch, short = 's')]
+    /// display only exercises that have been solved
+    solved: bool,
+}
+
 fn main() {
-    let matches = App::new("rustlings")
-        .version(crate_version!())
-        .author("Marisa, Carol Nichols")
-        .about("Rustlings is a collection of small exercises to get you used to writing and reading Rust code")
-        .arg(
-            Arg::with_name("nocapture")
-                .long("nocapture")
-                .help("Show outputs from the test exercises")
-        )
-        .subcommand(
-            SubCommand::with_name("verify")
-                .alias("v")
-                .about("Verifies all exercises according to the recommended order")
-        )
-        .subcommand(
-            SubCommand::with_name("watch")
-                .alias("w")
-                .about("Reruns `verify` when files were edited")
-        )
-        .subcommand(
-            SubCommand::with_name("run")
-                .alias("r")
-                .about("Runs/Tests a single exercise")
-                .arg(Arg::with_name("name").required(true).index(1)),
-        )
-        .subcommand(
-            SubCommand::with_name("hint")
-                .alias("h")
-                .about("Returns a hint for the current exercise")
-                .arg(Arg::with_name("name").required(true).index(1)),
-        )
-        .subcommand(
-            SubCommand::with_name("list")
-                .alias("l")
-                .about("Lists the exercises available in rustlings")
-                .arg(
-                    Arg::with_name("paths")
-                        .long("paths")
-                        .short("p")
-                        .conflicts_with("names")
-                        .help("Show only the paths of the exercises")
-                )
-                .arg(
-                    Arg::with_name("names")
-                        .long("names")
-                        .short("n")
-                        .conflicts_with("paths")
-                        .help("Show only the names of the exercises")
-                )
-                .arg(
-                    Arg::with_name("filter")
-                        .long("filter")
-                        .short("f")
-                        .takes_value(true)
-                        .empty_values(false)
-                        .help(
-                            "Provide a string to match the exercise names.\
-                            \nComma separated patterns are acceptable."
-                        )
-                )
-                .arg(
-                    Arg::with_name("unsolved")
-                        .long("unsolved")
-                        .short("u")
-                        .conflicts_with("solved")
-                        .help("Display only exercises not yet solved")
-                )
-                .arg(
-                    Arg::with_name("solved")
-                        .long("solved")
-                        .short("s")
-                        .conflicts_with("unsolved")
-                        .help("Display only exercises that have been solved")
-                )
-        )
-        .get_matches();
-
-    if matches.subcommand_name().is_none() {
+    let args: Args = argh::from_env();
+
+    if args.version {
+        println!("v{}", VERSION);
+        std::process::exit(0);
+    }
+
+    if args.nested.is_none() {
         println!();
         println!(r#"       welcome to...                      "#);
         println!(r#"                 _   _ _                  "#);
@@ -130,144 +136,129 @@ fn main() {
 
     let toml_str = &fs::read_to_string("info.toml").unwrap();
     let exercises = toml::from_str::<ExerciseList>(toml_str).unwrap().exercises;
-    let verbose = matches.is_present("nocapture");
+    let verbose = args.nocapture;
 
-    // Handle the list command
-    if let Some(list_m) = matches.subcommand_matches("list") {
-        if ["paths", "names"].iter().all(|k| !list_m.is_present(k)) {
-            println!("{:<17}\t{:<46}\t{:<7}", "Name", "Path", "Status");
-        }
-        let filters = list_m.value_of("filter").unwrap_or_default().to_lowercase();
-        let mut exercises_done: u16 = 0;
-        exercises.iter().for_each(|e| {
-            let fname = format!("{}", e.path.display());
-            let filter_cond = filters
-                .split(',')
-                .filter(|f| !f.trim().is_empty())
-                .any(|f| e.name.contains(&f) || fname.contains(&f));
-            let status = if e.looks_done() {
-                exercises_done = exercises_done + 1;
-                "Done"
-            } else {
-                "Pending"
-            };
-            let solve_cond = {
-                (e.looks_done() && list_m.is_present("solved"))
-                    || (!e.looks_done() && list_m.is_present("unsolved"))
-                    || (!list_m.is_present("solved") && !list_m.is_present("unsolved"))
-            };
-            if solve_cond && (filter_cond || !list_m.is_present("filter")) {
-                let line = if list_m.is_present("paths") {
-                    format!("{}\n", fname)
-                } else if list_m.is_present("names") {
-                    format!("{}\n", e.name)
+    let command = args.nested.unwrap_or_else(|| {
+        let text = fs::read_to_string("default_out.txt").unwrap();
+        println!("{}", text);
+        std::process::exit(0);
+    });
+    match command {
+        Subcommands::List(subargs) => {
+            if !subargs.paths && !subargs.names {
+                println!("{:<17}\t{:<46}\t{:<7}", "Name", "Path", "Status");
+            }
+            let mut exercises_done: u16 = 0;
+            let filters = subargs.filter.clone().unwrap_or_default().to_lowercase();
+            exercises.iter().for_each(|e| {
+                let fname = format!("{}", e.path.display());
+                let filter_cond = filters
+                    .split(',')
+                    .filter(|f| !f.trim().is_empty())
+                    .any(|f| e.name.contains(&f) || fname.contains(&f));
+                let status = if e.looks_done() {
+                    exercises_done += 1;
+                    "Done"
                 } else {
-                    format!("{:<17}\t{:<46}\t{:<7}\n", e.name, fname, status)
+                    "Pending"
+                };
+                let solve_cond = {
+                    (e.looks_done() && subargs.solved)
+                        || (!e.looks_done() && subargs.unsolved)
+                        || (!subargs.solved && !subargs.unsolved)
                 };
-                // Somehow using println! leads to the binary panicking
-                // when its output is piped.
-                // So, we're handling a Broken Pipe error and exiting with 0 anyway
-                let stdout = std::io::stdout();
-                {
-                    let mut handle = stdout.lock();
-                    handle.write_all(line.as_bytes()).unwrap_or_else(|e| {
-                        match e.kind() {
-                            std::io::ErrorKind::BrokenPipe => std::process::exit(0),
-                            _ => std::process::exit(1),
-                        };
-                    });
+                if solve_cond && (filter_cond || subargs.filter.is_none()) {
+                    let line = if subargs.paths {
+                        format!("{}\n", fname)
+                    } else if subargs.names {
+                        format!("{}\n", e.name)
+                    } else {
+                        format!("{:<17}\t{:<46}\t{:<7}\n", e.name, fname, status)
+                    };
+                    // Somehow using println! leads to the binary panicking
+                    // when its output is piped.
+                    // So, we're handling a Broken Pipe error and exiting with 0 anyway
+                    let stdout = std::io::stdout();
+                    {
+                        let mut handle = stdout.lock();
+                        handle.write_all(line.as_bytes()).unwrap_or_else(|e| {
+                            match e.kind() {
+                                std::io::ErrorKind::BrokenPipe => std::process::exit(0),
+                                _ => std::process::exit(1),
+                            };
+                        });
+                    }
                 }
-            }
-        });
-        let percentage_progress = exercises_done as f32 / exercises.len() as f32 * 100.0;
-        println!(
-            "Progress: You completed {} / {} exercises ({:.2} %).",
-            exercises_done,
-            exercises.len(),
-            percentage_progress
-        );
-        std::process::exit(0);
-    }
-
-    // Handle the run command
-    if let Some(ref matches) = matches.subcommand_matches("run") {
-        let name = matches.value_of("name").unwrap();
-
-        let matching_exercise = |e: &&Exercise| name == e.name;
-
-        let exercise = exercises.iter().find(matching_exercise).unwrap_or_else(|| {
-            println!("No exercise found for your given name!");
-            std::process::exit(1)
-        });
+            });
+            let percentage_progress = exercises_done as f32 / exercises.len() as f32 * 100.0;
+            println!(
+                "Progress: You completed {} / {} exercises ({:.2} %).",
+                exercises_done,
+                exercises.len(),
+                percentage_progress
+            );
+            std::process::exit(0);
+        }
 
-        run(&exercise, verbose).unwrap_or_else(|_| std::process::exit(1));
-    }
+        Subcommands::Run(subargs) => {
+            let exercise = find_exercise(subargs.name, exercises);
 
-    if let Some(ref matches) = matches.subcommand_matches("hint") {
-        let name = matches.value_of("name").unwrap();
+            run(&exercise, verbose).unwrap_or_else(|_| std::process::exit(1));
+        }
 
-        let exercise = exercises
-            .iter()
-            .find(|e| name == e.name)
-            .unwrap_or_else(|| {
-                println!("No exercise found for your given name!");
-                std::process::exit(1)
-            });
+        Subcommands::Hint(subargs) => {
+            let exercise = find_exercise(subargs.name, exercises);
 
-        println!("{}", exercise.hint);
-    }
+            println!("{}", exercise.hint);
+        }
 
-    // Handle the verify command
-    if matches.subcommand_matches("verify").is_some() {
-        verify(&exercises, verbose).unwrap_or_else(|_| std::process::exit(1));
-    }
+        Subcommands::Verify(_subargs) => {
+            verify(&exercises, verbose).unwrap_or_else(|_| std::process::exit(1));
+        }
 
-    // Handle the watch command
-    if matches.subcommand_matches("watch").is_some() {
-        if let Err(e) = watch(&exercises, verbose) {
+        Subcommands::Watch(_subargs) => {
+            if let Err(e) = watch(&exercises, verbose) {
+                println!(
+                    "Error: Could not watch your progress. Error message was {:?}.",
+                    e
+                );
+                println!("Most likely you've run out of disk space or your 'inotify limit' has been reached.");
+                std::process::exit(1);
+            }
             println!(
-                "Error: Could not watch your progress. Error message was {:?}.",
-                e
+                "{emoji} All exercises completed! {emoji}",
+                emoji = Emoji("🎉", "★")
             );
-            println!("Most likely you've run out of disk space or your 'inotify limit' has been reached.");
-            std::process::exit(1);
+            println!();
+            println!("+----------------------------------------------------+");
+            println!("|          You made it to the Fe-nish line!          |");
+            println!("+--------------------------  ------------------------+");
+            println!("                          \\/                         ");
+            println!("     ▒▒          ▒▒▒▒▒▒▒▒      ▒▒▒▒▒▒▒▒          ▒▒   ");
+            println!("   ▒▒▒▒  ▒▒    ▒▒        ▒▒  ▒▒        ▒▒    ▒▒  ▒▒▒▒ ");
+            println!("   ▒▒▒▒  ▒▒  ▒▒            ▒▒            ▒▒  ▒▒  ▒▒▒▒ ");
+            println!(" ░░▒▒▒▒░░▒▒  ▒▒            ▒▒            ▒▒  ▒▒░░▒▒▒▒ ");
+            println!("   ▓▓▓▓▓▓▓▓  ▓▓      ▓▓██  ▓▓  ▓▓██      ▓▓  ▓▓▓▓▓▓▓▓ ");
+            println!("     ▒▒▒▒    ▒▒      ████  ▒▒  ████      ▒▒░░  ▒▒▒▒   ");
+            println!("       ▒▒  ▒▒▒▒▒▒        ▒▒▒▒▒▒        ▒▒▒▒▒▒  ▒▒     ");
+            println!("         ▒▒▒▒▒▒▒▒▒▒▓▓▓▓▓▓▒▒▒▒▒▒▒▒▓▓▒▒▓▓▒▒▒▒▒▒▒▒       ");
+            println!("           ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒         ");
+            println!("             ▒▒▒▒▒▒▒▒▒▒██▒▒▒▒▒▒██▒▒▒▒▒▒▒▒▒▒           ");
+            println!("           ▒▒  ▒▒▒▒▒▒▒▒▒▒██████▒▒▒▒▒▒▒▒▒▒  ▒▒         ");
+            println!("         ▒▒    ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒    ▒▒       ");
+            println!("       ▒▒    ▒▒    ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒    ▒▒    ▒▒     ");
+            println!("       ▒▒  ▒▒    ▒▒                  ▒▒    ▒▒  ▒▒     ");
+            println!("           ▒▒  ▒▒                      ▒▒  ▒▒         ");
+            println!();
+            println!("We hope you enjoyed learning about the various aspects of Rust!");
+            println!(
+                "If you noticed any issues, please don't hesitate to report them to our repo."
+            );
+            println!("You can also contribute your own exercises to help the greater community!");
+            println!();
+            println!("Before reporting an issue or contributing, please read our guidelines:");
+            println!("https://github.com/rust-lang/rustlings/blob/main/CONTRIBUTING.md");
         }
-        println!(
-            "{emoji} All exercises completed! {emoji}",
-            emoji = Emoji("🎉", "★")
-        );
-        println!();
-        println!("+----------------------------------------------------+");
-        println!("|          You made it to the Fe-nish line!          |");
-        println!("+--------------------------  ------------------------+");
-        println!("                          \\/                         ");
-        println!("     ▒▒          ▒▒▒▒▒▒▒▒      ▒▒▒▒▒▒▒▒          ▒▒   ");
-        println!("   ▒▒▒▒  ▒▒    ▒▒        ▒▒  ▒▒        ▒▒    ▒▒  ▒▒▒▒ ");
-        println!("   ▒▒▒▒  ▒▒  ▒▒            ▒▒            ▒▒  ▒▒  ▒▒▒▒ ");
-        println!(" ░░▒▒▒▒░░▒▒  ▒▒            ▒▒            ▒▒  ▒▒░░▒▒▒▒ ");
-        println!("   ▓▓▓▓▓▓▓▓  ▓▓      ▓▓██  ▓▓  ▓▓██      ▓▓  ▓▓▓▓▓▓▓▓ ");
-        println!("     ▒▒▒▒    ▒▒      ████  ▒▒  ████      ▒▒░░  ▒▒▒▒   ");
-        println!("       ▒▒  ▒▒▒▒▒▒        ▒▒▒▒▒▒        ▒▒▒▒▒▒  ▒▒     ");
-        println!("         ▒▒▒▒▒▒▒▒▒▒▓▓▓▓▓▓▒▒▒▒▒▒▒▒▓▓▒▒▓▓▒▒▒▒▒▒▒▒       ");
-        println!("           ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒         ");
-        println!("             ▒▒▒▒▒▒▒▒▒▒██▒▒▒▒▒▒██▒▒▒▒▒▒▒▒▒▒           ");
-        println!("           ▒▒  ▒▒▒▒▒▒▒▒▒▒██████▒▒▒▒▒▒▒▒▒▒  ▒▒         ");
-        println!("         ▒▒    ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒    ▒▒       ");
-        println!("       ▒▒    ▒▒    ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒    ▒▒    ▒▒     ");
-        println!("       ▒▒  ▒▒    ▒▒                  ▒▒    ▒▒  ▒▒     ");
-        println!("           ▒▒  ▒▒                      ▒▒  ▒▒         ");
-        println!();
-        println!("We hope you enjoyed learning about the various aspects of Rust!");
-        println!("If you noticed any issues, please don't hesitate to report them to our repo.");
-        println!("You can also contribute your own exercises to help the greater community!");
-        println!();
-        println!("Before reporting an issue or contributing, please read our guidelines:");
-        println!("https://github.com/rust-lang/rustlings/blob/main/CONTRIBUTING.md");
-    }
-
-    if matches.subcommand_name().is_none() {
-        let text = fs::read_to_string("default_out.txt").unwrap();
-        println!("{}", text);
     }
 }
 
@@ -294,6 +285,18 @@ fn spawn_watch_shell(failed_exercise_hint: &Arc<Mutex<Option<String>>>) {
     });
 }
 
+fn find_exercise(name: String, exercises: Vec<Exercise>) -> Exercise {
+    let matching_exercise = |e: &Exercise| name == e.name;
+
+    exercises
+        .into_iter()
+        .find(matching_exercise)
+        .unwrap_or_else(|| {
+            println!("No exercise found for your given name!");
+            std::process::exit(1)
+        })
+}
+
 fn watch(exercises: &[Exercise], verbose: bool) -> notify::Result<()> {
     /* Clears the terminal with an ANSI escape code.
     Works in UNIX and newer Windows terminals. */

From 6177b6e126852027b689ebab4e0796b2984f987b Mon Sep 17 00:00:00 2001
From: mokou <mokou@fastmail.com>
Date: Wed, 21 Apr 2021 14:47:53 +0200
Subject: [PATCH 2/3] chore: Fix integration tests

---
 tests/integration_tests.rs | 67 ++++++++++++++------------------------
 1 file changed, 24 insertions(+), 43 deletions(-)

diff --git a/tests/integration_tests.rs b/tests/integration_tests.rs
index 1bd3bf7e..be9af965 100644
--- a/tests/integration_tests.rs
+++ b/tests/integration_tests.rs
@@ -24,7 +24,7 @@ fn fails_when_in_wrong_dir() {
 fn verify_all_success() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .arg("v")
+        .arg("verify")
         .current_dir("tests/fixture/success")
         .assert()
         .success();
@@ -34,7 +34,7 @@ fn verify_all_success() {
 fn verify_fails_if_some_fails() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .arg("v")
+        .arg("verify")
         .current_dir("tests/fixture/failure")
         .assert()
         .code(1);
@@ -44,7 +44,7 @@ fn verify_fails_if_some_fails() {
 fn run_single_compile_success() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "compSuccess"])
+        .args(&["run", "compSuccess"])
         .current_dir("tests/fixture/success/")
         .assert()
         .success();
@@ -54,7 +54,7 @@ fn run_single_compile_success() {
 fn run_single_compile_failure() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "compFailure"])
+        .args(&["run", "compFailure"])
         .current_dir("tests/fixture/failure/")
         .assert()
         .code(1);
@@ -64,7 +64,7 @@ fn run_single_compile_failure() {
 fn run_single_test_success() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "testSuccess"])
+        .args(&["run", "testSuccess"])
         .current_dir("tests/fixture/success/")
         .assert()
         .success();
@@ -74,7 +74,7 @@ fn run_single_test_success() {
 fn run_single_test_failure() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "testFailure"])
+        .args(&["run", "testFailure"])
         .current_dir("tests/fixture/failure/")
         .assert()
         .code(1);
@@ -84,7 +84,7 @@ fn run_single_test_failure() {
 fn run_single_test_not_passed() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "testNotPassed.rs"])
+        .args(&["run", "testNotPassed.rs"])
         .current_dir("tests/fixture/failure/")
         .assert()
         .code(1);
@@ -94,7 +94,7 @@ fn run_single_test_not_passed() {
 fn run_single_test_no_filename() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .arg("r")
+        .arg("run")
         .current_dir("tests/fixture/")
         .assert()
         .code(1);
@@ -104,7 +104,7 @@ fn run_single_test_no_filename() {
 fn run_single_test_no_exercise() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "compNoExercise.rs"])
+        .args(&["run", "compNoExercise.rs"])
         .current_dir("tests/fixture/failure")
         .assert()
         .code(1);
@@ -114,7 +114,7 @@ fn run_single_test_no_exercise() {
 fn get_hint_for_single_test() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["h", "testFailure"])
+        .args(&["hint", "testFailure"])
         .current_dir("tests/fixture/failure")
         .assert()
         .code(0)
@@ -131,10 +131,15 @@ fn all_exercises_require_confirmation() {
             file.read_to_string(&mut s).unwrap();
             s
         };
-        source.matches("// I AM NOT DONE").next().unwrap_or_else(|| panic!(
-            "There should be an `I AM NOT DONE` annotation in {:?}",
-            path
-        ));
+        source
+            .matches("// I AM NOT DONE")
+            .next()
+            .unwrap_or_else(|| {
+                panic!(
+                    "There should be an `I AM NOT DONE` annotation in {:?}",
+                    path
+                )
+            });
     }
 }
 
@@ -142,7 +147,7 @@ fn all_exercises_require_confirmation() {
 fn run_compile_exercise_does_not_prompt() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "pending_exercise"])
+        .args(&["run", "pending_exercise"])
         .current_dir("tests/fixture/state")
         .assert()
         .code(0)
@@ -153,7 +158,7 @@ fn run_compile_exercise_does_not_prompt() {
 fn run_test_exercise_does_not_prompt() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "pending_test_exercise"])
+        .args(&["run", "pending_test_exercise"])
         .current_dir("tests/fixture/state")
         .assert()
         .code(0)
@@ -164,7 +169,7 @@ fn run_test_exercise_does_not_prompt() {
 fn run_single_test_success_with_output() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["--nocapture", "r", "testSuccess"])
+        .args(&["--nocapture", "run", "testSuccess"])
         .current_dir("tests/fixture/success/")
         .assert()
         .code(0)
@@ -175,7 +180,7 @@ fn run_single_test_success_with_output() {
 fn run_single_test_success_without_output() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "testSuccess"])
+        .args(&["run", "testSuccess"])
         .current_dir("tests/fixture/success/")
         .assert()
         .code(0)
@@ -192,26 +197,6 @@ fn run_rustlings_list() {
         .success();
 }
 
-#[test]
-fn run_rustlings_list_conflicting_display_options() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .args(&["list", "--names", "--paths"])
-        .current_dir("tests/fixture/success")
-        .assert()
-        .failure();
-}
-
-#[test]
-fn run_rustlings_list_conflicting_solve_options() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .args(&["list", "--solved", "--unsolved"])
-        .current_dir("tests/fixture/success")
-        .assert()
-        .failure();
-}
-
 #[test]
 fn run_rustlings_list_no_pending() {
     Command::cargo_bin("rustlings")
@@ -231,10 +216,7 @@ fn run_rustlings_list_both_done_and_pending() {
         .current_dir("tests/fixture/state")
         .assert()
         .success()
-        .stdout(
-            predicates::str::contains("Done")
-                .and(predicates::str::contains("Pending"))
-        );
+        .stdout(predicates::str::contains("Done").and(predicates::str::contains("Pending")));
 }
 
 #[test]
@@ -258,4 +240,3 @@ fn run_rustlings_list_without_done() {
         .success()
         .stdout(predicates::str::contains("Done").not());
 }
-

From 347f30bd867343c5ace1097e085a1f7e356553f7 Mon Sep 17 00:00:00 2001
From: mokou <mokou@fastmail.com>
Date: Wed, 21 Apr 2021 16:21:56 +0200
Subject: [PATCH 3/3] fix(main): Let find_exercise work with borrows

---
 src/main.rs | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 5af5febc..a95a09d9 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -201,13 +201,13 @@ fn main() {
         }
 
         Subcommands::Run(subargs) => {
-            let exercise = find_exercise(subargs.name, exercises);
+            let exercise = find_exercise(&subargs.name, &exercises);
 
             run(&exercise, verbose).unwrap_or_else(|_| std::process::exit(1));
         }
 
         Subcommands::Hint(subargs) => {
-            let exercise = find_exercise(subargs.name, exercises);
+            let exercise = find_exercise(&subargs.name, &exercises);
 
             println!("{}", exercise.hint);
         }
@@ -285,14 +285,12 @@ fn spawn_watch_shell(failed_exercise_hint: &Arc<Mutex<Option<String>>>) {
     });
 }
 
-fn find_exercise(name: String, exercises: Vec<Exercise>) -> Exercise {
-    let matching_exercise = |e: &Exercise| name == e.name;
-
+fn find_exercise<'a>(name: &str, exercises: &'a [Exercise]) -> &'a Exercise {
     exercises
-        .into_iter()
-        .find(matching_exercise)
+        .iter()
+        .find(|e| e.name == name)
         .unwrap_or_else(|| {
-            println!("No exercise found for your given name!");
+            println!("No exercise found for '{}'!", name);
             std::process::exit(1)
         })
 }