Switch to using clap crate for command line arguments

Cargo.lock

@@ -8,12 +8,6 @@ version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ee2a4ec343196209d6594e19543ae87a39f96d5534d7174822a3ad825dd6ed7e"
 
-[[package]]
-name = "argparse"
-version = "0.2.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3f8ebf5827e4ac4fd5946560e6a99776ea73b596d80898f357007317a7141e47"
-
 [[package]]
 name = "autocfg"
 version = "1.0.1"
@@ -26,6 +20,12 @@ version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1b20b618342cf9891c292c4f5ac2cde7287cc5c87e87e9c769d617793607dec1"
 
+[[package]]
+name = "bitflags"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
 [[package]]
 name = "bstr"
 version = "0.2.13"
@@ -50,6 +50,12 @@ version = "1.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08c48aae112d48ed9f069b33538ea9e3e90aa263cfa3d1c24309612b1f7472de"
 
+[[package]]
+name = "cc"
+version = "1.0.78"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a20104e2335ce8a659d6dd92a51a767a0c062599c73b343fd152cb401e828c3d"
+
 [[package]]
 name = "cfg-if"
 version = "0.1.10"
@@ -62,6 +68,43 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "clap"
+version = "4.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ec7a4128863c188deefe750ac1d1dfe66c236909f845af04beed823638dc1b2"
+dependencies = [
+ "bitflags",
+ "clap_derive",
+ "clap_lex",
+ "is-terminal",
+ "once_cell",
+ "strsim",
+ "termcolor",
+]
+
+[[package]]
+name = "clap_derive"
+version = "4.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "684a277d672e91966334af371f1a7b5833f9aa00b07c84e92fbce95e00208ce8"
+dependencies = [
+ "heck",
+ "proc-macro-error",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "clap_lex"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "783fe232adfca04f90f56201b26d79682d4cd2625e0bc7290b95123afe558ade"
+dependencies = [
+ "os_str_bytes",
+]
+
 [[package]]
 name = "const_fn"
 version = "0.4.2"
@@ -175,6 +218,27 @@ version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a246d82be1c9d791c5dfde9a2bd045fc3cbba3fa2b11ad558f27d01712f00569"
 
+[[package]]
+name = "errno"
+version = "0.2.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f639046355ee4f37944e44f60642c6f3a7efa3cf6b78c78a0d989a8ce6c396a1"
+dependencies = [
+ "errno-dragonfly",
+ "libc",
+ "winapi",
+]
+
+[[package]]
+name = "errno-dragonfly"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa68f1b12764fab894d2755d2518754e71b4fd80ecfb822714a1206c2aab39bf"
+dependencies = [
+ "cc",
+ "libc",
+]
+
 [[package]]
 name = "flate2"
 version = "1.0.17"
@@ -198,6 +262,43 @@ dependencies = [
  "wasi",
 ]
 
+[[package]]
+name = "heck"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2540771e65fc8cb83cd6e8a237f70c319bd5c29f78ed1084ba5d50eeac86f7f9"
+
+[[package]]
+name = "hermit-abi"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee512640fe35acbfb4bb779db6f0d80704c2cacfa2e39b601ef3e3f47d1ae4c7"
+dependencies = [
+ "libc",
+]
+
+[[package]]
+name = "io-lifetimes"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e7d6c6f8c91b4b9ed43484ad1a938e393caf35960fce7f82a040497207bd8e9e"
+dependencies = [
+ "libc",
+ "windows-sys",
+]
+
+[[package]]
+name = "is-terminal"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "28dfb6c8100ccc63462345b67d1bbc3679177c75ee4bf59bf29c8b1d110b8189"
+dependencies = [
+ "hermit-abi",
+ "io-lifetimes",
+ "rustix",
+ "windows-sys",
+]
+
 [[package]]
 name = "itoa"
 version = "0.4.6"
@@ -221,9 +322,9 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "libc"
-version = "0.2.131"
+version = "0.2.139"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "04c3b4822ccebfa39c02fc03d1534441b22ead323fa0f48bb7ddd8e6ba076a40"
+checksum = "201de327520df007757c1f0adce6e827fe8562fbc28bfd9c15571c66ca1f5f79"
 
 [[package]]
 name = "linked-hash-map"
@@ -231,6 +332,12 @@ version = "0.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7fb9b38af92608140b86b693604b9ffcc5824240a484d1ecd4795bacb2fe88f3"
 
+[[package]]
+name = "linux-raw-sys"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f051f77a7c8e6957c0696eac88f26b0117e54f52d3fc682ab19397a8812846a4"
+
 [[package]]
 name = "log"
 version = "0.4.11"
@@ -274,6 +381,28 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "num_cpus"
+version = "1.15.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fac9e2da13b5eb447a6ce3d392f23a29d8694bff781bf03a16cd9ac8697593b"
+dependencies = [
+ "hermit-abi",
+ "libc",
+]
+
+[[package]]
+name = "once_cell"
+version = "1.17.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f61fba1741ea2b3d6a1e3178721804bb716a68a6aeba1149b5d52e3d464ea66"
+
+[[package]]
+name = "os_str_bytes"
+version = "6.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b7820b9daea5457c9f21c69448905d723fbd21136ccf521748f23fd49e723ee"
+
 [[package]]
 name = "owned_ttf_parser"
 version = "0.12.1"
@@ -307,6 +436,30 @@ dependencies = [
  "time",
 ]
 
+[[package]]
+name = "proc-macro-error"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "da25490ff9892aab3fcf7c36f08cfb902dd3e71ca0f9f9517bea02a73a5ce38c"
+dependencies = [
+ "proc-macro-error-attr",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "version_check",
+]
+
+[[package]]
+name = "proc-macro-error-attr"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1be40180e52ecc98ad80b184934baf3d0d29f979574e439af5a55274b35f869"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "version_check",
+]
+
 [[package]]
 name = "proc-macro-hack"
 version = "0.5.18"
@@ -315,18 +468,18 @@ checksum = "99c605b9a0adc77b7211c6b1f722dcb613d68d66859a44f3d485a6da332b0598"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.26"
+version = "1.0.50"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a152013215dca273577e18d2bf00fa862b89b24169fb78c4c95aeb07992c9cec"
+checksum = "6ef7d57beacfaf2d8aee5937dab7b7f28de3cb8b1828479bb5de2a7106f2bae2"
 dependencies = [
- "unicode-xid",
+ "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.7"
+version = "1.0.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aa563d17ecb180e500da1cfd2b028310ac758de548efdd203e18f283af693f37"
+checksum = "8856d8364d252a14d474036ea1358d63c9e6965c8e5c1885c18f73d70bff9c7b"
 dependencies = [
  "proc-macro2",
 ]
@@ -379,6 +532,20 @@ dependencies = [
  "semver",
 ]
 
+[[package]]
+name = "rustix"
+version = "0.36.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d4fdebc4b395b7fbb9ab11e462e20ed9051e7b16e42d24042c776eca0ac81b03"
+dependencies = [
+ "bitflags",
+ "errno",
+ "io-lifetimes",
+ "libc",
+ "linux-raw-sys",
+ "windows-sys",
+]
+
 [[package]]
 name = "ryu"
 version = "1.0.5"
@@ -492,25 +659,41 @@ version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "213701ba3370744dcd1a12960caa4843b3d68b4d1c0a5d575e0d65b2ee9d16c0"
 
+[[package]]
+name = "strsim"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
+
 [[package]]
 name = "sudoku_solver"
-version = "0.2.0"
+version = "0.3.0"
 dependencies = [
- "argparse",
+ "clap",
  "csv",
+ "num_cpus",
  "printpdf",
  "rand",
 ]
 
 [[package]]
 name = "syn"
-version = "1.0.69"
+version = "1.0.107"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "48fe99c6bd8b1cc636890bcc071842de909d902c81ac7dab53ba33c421ab8ffb"
+checksum = "1f4064b5b16e03ae50984a5a8ed5d4f8803e6bc1fd170a3cda91a1be4b18e3f5"
 dependencies = [
  "proc-macro2",
  "quote",
- "unicode-xid",
+ "unicode-ident",
+]
+
+[[package]]
+name = "termcolor"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "be55cf8942feac5c765c2c993422806843c9a9a45d4d5c407ad6dd2ea95eb9b6"
+dependencies = [
+ "winapi-util",
 ]
 
 [[package]]
@@ -558,10 +741,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7ae2f58a822f08abdaf668897e96a5656fe72f5a9ce66422423e8849384872e6"
 
 [[package]]
-name = "unicode-xid"
+name = "unicode-ident"
-version = "0.2.1"
+version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f7fe0bb3479651439c9112f72b6c505038574c9fbb575ed1bf3b797fa39dd564"
+checksum = "84a22b9f218b40614adcb3f4ff08b703773ad44fa9423e4e0d346d5db86e4ebc"
 
 [[package]]
 name = "version_check"
@@ -651,8 +834,74 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 
+[[package]]
+name = "winapi-util"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "70ec6ce85bb158151cae5e5c87f95a8e97d2c0c4b001223f33a334e3ce5de178"
+dependencies = [
+ "winapi",
+]
+
 [[package]]
 name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
+
+[[package]]
+name = "windows-sys"
+version = "0.42.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a3e1820f08b8513f676f7ab6c1f99ff312fb97b553d30ff4dd86f9f15728aa7"
+dependencies = [
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.42.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8c9864e83243fdec7fc9c5444389dcbbfd258f745e7853198f365e3c4968a608"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.42.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4c8b1b673ffc16c47a9ff48570a9d85e25d265735c503681332589af6253c6c7"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.42.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "de3887528ad530ba7bdbb1faa8275ec7a1155a45ffa57c37993960277145d640"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.42.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bf4d1122317eddd6ff351aa852118a2418ad4214e6613a50e0191f7004372605"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.42.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c1040f221285e17ebccbc2591ffdc2d44ee1f9186324dd3e84e99ac68d699c45"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.42.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "628bfdf232daa22b0d64fdb62b09fcc36bb01f05a3939e20ab73aaf9470d0463"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.42.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "447660ad36a13288b1db4d4248e857b510e8c3a225c822ba4fb748c0aafecffd"

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "sudoku_solver"
-version = "0.2.0"
+version = "0.3.0"
 authors = ["Joel Therrien <joel@joeltherrien.ca>"]
 edition = "2021"
 
@@ -8,8 +8,9 @@ edition = "2021"
 
 [dependencies]
 csv = "1.1.3"
-argparse = "0.2.2"
+clap = { version = "4.1.1", features = ['derive']}
 printpdf = "0.5.2"
+num_cpus = "1.15.0"
 
 [dependencies.rand]
 version = "0.8.5"

src/bin/generator.rs

@@ -2,15 +2,17 @@ use rand::prelude::*;
 use std::cmp::Ordering as ComparableOrdering;
 use std::error::Error;
 use std::io::Write;
-use std::process::exit;
 use std::str::FromStr;
 use std::sync::atomic::{AtomicI64, Ordering};
 use std::sync::{mpsc, Arc};
 use std::thread;
 use sudoku_solver::grid::{CellValue, Grid};
 use sudoku_solver::solver::{SolveController, SolveStatistics};
+use clap::{Parser, ValueEnum};
 
-#[derive(Clone, Copy)] // Needed for argparse
+use num_cpus;
+
+#[derive(Clone, Copy, ValueEnum, Debug)]
 enum Difficulty {
     Challenge,
     Hard,
@@ -89,122 +91,91 @@ impl FromStr for Difficulty {
     }
 }
 
+/// Generate Sudoku Puzzles
+#[derive(Parser, Debug)]
+#[clap(author, version, about, long_about = None)]
+struct RunParams {
+
+    /// Sets debug mode
+    #[arg(long, default_value_t=false)]
+    debug: bool,
+
+    /// Sets maximum allowed puzzle hints
+    #[arg(short, long, default_value_t=81)]
+    max_hints: u64,
+
+    /// Sets maximum puzzle attempts per generation
+    #[arg(long, default_value_t=100)]
+    attempts: usize,
+
+    /// Sets output filename; filename should end in CSV or PDF.
+    ///
+    /// The type of file generated depends on the file extension used, so a PDF file will be generated for a .pdf file and
+    /// a CSV file will be generated for a .csv file.
+    #[arg(action)]
+    filename: String,
+
+    /// Sets number puzzles
+    #[arg(short, long, default_value_t=1)]
+    puzzles: usize,
+
+    /// Sets difficulty
+    #[arg(long, value_enum, default_value="hard")]
+    difficulty: Difficulty,
+
+    /// Sets whether to print notes
+    ///
+    /// This parameter is only applicable for PDF outputs.
+    #[arg(short, long, default_value_t=false)]
+    notes: bool,
+
+}
+
 fn main() {
-    let mut debug = false;
-    let mut max_hints = 81;
-    let mut max_attempts: Option<usize> = None;
-    let mut filename= String::new();
-    let mut number_puzzles: usize = 1;
-    let mut difficulty = Difficulty::Hard;
-    let mut threads = 1;
-    let mut print_possibilities = false;
 
-    {
+    let run_params: RunParams = RunParams::parse();
-        // this block limits scope of borrows by ap.refer() method
-        let mut ap = argparse::ArgumentParser::new();
-        ap.set_description("Generate Sudoku puzzles");
-        ap.refer(&mut debug)
-            .add_option(&["--debug"], argparse::StoreTrue, "Run in debug mode");
 
-        ap.refer(&mut max_hints).add_option(
+    let solve_controller = run_params.difficulty.map_to_solve_controller();
-            &["--hints"],
+    let total_attempts = run_params.puzzles * run_params.attempts;
-            argparse::Store,
+    let threads = num_cpus::get();
-            "Only return a puzzle with less than or equal to this number of hints",
-        );
 
-        ap.refer(&mut max_attempts)
+    println!("Processing using {} threads", threads);
-            .add_option(&["--attempts"], argparse::StoreOption,
-                        "Number of puzzles attempted to find the appropriate puzzles; default is 100*(num-puzzles)");
 
-        ap.refer(&mut filename).add_argument(
+    let mut generated_grids_vec = run_multi_threaded(
-            "filename",
+        total_attempts,
-            argparse::Store,
+        run_params.puzzles,
-            "Filename to store puzzle(s) in as a CSV or pdf",
+        run_params.max_hints,
-        ).required();
-
-        ap.refer(&mut number_puzzles).add_option(
-            &["--num-puzzles"],
-            argparse::Store,
-            "Number of puzzles to generate; default 1"
-        );
-
-        ap.refer(&mut difficulty).add_option(
-            &["-d", "--difficulty"],
-            argparse::Store,
-            "Max difficulty setting; values are EASY, MEDIUM, HARD, or CHALLENGE",
-        );
-
-        ap.refer(&mut threads).add_option(
-            &["--threads"],
-            argparse::Store,
-            "Number of threads to use when generating possible puzzles",
-        );
-
-        ap.refer(&mut print_possibilities).add_option(
-            &["-p", "--possibilities"],
-            argparse::StoreTrue,
-            "Include each cell's possibilities in the output; applies only to PDF output",
-        );
-
-        ap.parse_args_or_exit();
-    }
-
-    let max_attempts = max_attempts.unwrap_or(100 * number_puzzles);
-
-    let solve_controller = difficulty.map_to_solve_controller();
-
-    let mut generated_grids_vec = match threads.cmp(&1) {
-        ComparableOrdering::Less => {
-            eprintln!("--threads must be at least 1");
-            exit(1);
-        }
-        ComparableOrdering::Equal => {
-            let mut rng = SmallRng::from_entropy();
-            get_puzzle_matching_conditions(
-                &mut rng,
-                &difficulty,
-                &solve_controller,
-                max_hints,
-                &AtomicI64::new(number_puzzles as i64),
-                &AtomicI64::new(max_attempts as i64),
-                debug,
-            )
-        }
-
-        ComparableOrdering::Greater => run_multi_threaded(
-            max_attempts,
-            number_puzzles,
-            max_hints,
         threads,
-            debug,
+        run_params.debug,
         solve_controller,
-            difficulty,
+        run_params.difficulty,
-        ),
+    );
-    };
 
 
 
-    if generated_grids_vec.len() < number_puzzles {
+    if generated_grids_vec.len() < run_params.puzzles {
-        println!("Unable to find {} puzzles in {} tries; instead {} puzzles were found.", number_puzzles, max_attempts, generated_grids_vec.len());
+        println!("Unable to find {} puzzles in {} tries; instead {} puzzles were found.", run_params.puzzles, total_attempts, generated_grids_vec.len());
         return
     }
 
     let mut grids_vec: Vec<Grid> = Vec::new();
-    for _ in 0..number_puzzles {
+    for _ in 0..run_params.puzzles {
         // It may happen that we generated more puzzles than we needed  - that's okay, we'll just ignore those
         grids_vec.push(generated_grids_vec.pop().unwrap().grid);
     }
 
 
     // check if we save to a csv or a pdf
-    if filename.ends_with(".pdf") {
+    if run_params.filename.ends_with(".pdf") {
-        sudoku_solver::pdf::draw_grids(&grids_vec, &filename, print_possibilities).unwrap();
+        sudoku_solver::pdf::draw_grids(&grids_vec, &run_params.filename, run_params.notes).unwrap();
-        println!("Grid saved as pdf to {}", filename);
+        println!("Grid saved as pdf to {}", run_params.filename);
     } else {
-        save_grids_csv(&grids_vec, &filename).unwrap();
+        save_grids_csv(&grids_vec, &run_params.filename).unwrap();
-        println!("Grid saved as CSV to {}", filename);
+        println!("Grid saved as CSV to {}", run_params.filename);
     }
 
+
+
 }
 
 struct GeneratedGrid {
@@ -226,7 +197,7 @@ fn run_multi_threaded(
     max_attempts: usize,
     number_puzzles: usize,
     max_hints: u64,
-    threads: u64,
+    threads: usize,
     debug: bool,
     solve_controller: SolveController,
     difficulty: Difficulty,

src/bin/solver.rs

@@ -1,35 +1,35 @@
 use std::str::FromStr;
+use clap::Parser;
 
 use sudoku_solver::grid::Grid;
 use sudoku_solver::solver::solve_grid;
 
+/// Test text here
+///
+/// Second test text here setence;
+#[derive(Parser, Debug)]
+#[clap(author, version, about, long_about = None)]
+struct RunParams {
+    /// Sets debug mode
+    #[arg(long, default_value_t=false)]
+    debug: bool,
+
+    /// Path to puzzle CSV file to solve
+    #[arg(action)]
+    filename: String,
+}
+
 fn main() {
-    let mut debug = false;
+    let params: RunParams = RunParams::parse();
-    let mut filename = String::new();
-    {
-        // this block limits scope of borrows by ap.refer() method
-        let mut ap = argparse::ArgumentParser::new();
-        ap.set_description("Solve Sudoku puzzles");
-        ap.refer(&mut debug)
-            .add_option(&["--debug"], argparse::StoreTrue, "Run in debug mode");
 
-        ap.refer(&mut filename).required().add_argument(
+    if params.debug {
-            "filename",
-            argparse::Store,
-            "Path to puzzle CSV file",
-        );
-
-        ap.parse_args_or_exit();
-    }
-
-    if debug {
         unsafe {
             sudoku_solver::grid::DEBUG = true;
             sudoku_solver::solver::DEBUG = true;
         }
     }
 
-    let mut grid = match read_grid(&filename) {
+    let mut grid = match read_grid(&params.filename) {
         Ok(grid) => grid,
         Err(e) => {
             eprintln!("Error while reading grid: \"{}\"", e);