Integrate with clap for CLI argument parsing

Cargo.lock

@@ -12,6 +12,41 @@ version = "1.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "822d7d63e0c0260a050f6b1f0d316f5c79b9eab830aca526ed904e1011bd64ca"
 
+[[package]]
+name = "bitflags"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
+
+[[package]]
+name = "clap"
+version = "3.0.0-beta.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4bd1061998a501ee7d4b6d449020df3266ca3124b941ec56cf2005c3779ca142"
+dependencies = [
+ "bitflags",
+ "clap_derive",
+ "indexmap",
+ "lazy_static",
+ "os_str_bytes",
+ "textwrap",
+ "unicode-width",
+ "vec_map",
+]
+
+[[package]]
+name = "clap_derive"
+version = "3.0.0-beta.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "370f715b81112975b1b69db93e0b56ea4cd4e5002ac43b2da8474106a54096a1"
+dependencies = [
+ "heck",
+ "proc-macro-error",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "gmp-mpfr-sys"
 version = "1.4.5"
@@ -22,6 +57,37 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "hashbrown"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d7afe4a420e3fe79967a00898cc1f4db7c8a49a9333a29f8a4bd76a253d5cd04"
+
+[[package]]
+name = "heck"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "87cbf45460356b7deeb5e3415b5563308c0a9b057c85e12b06ad551f98d0a6ac"
+dependencies = [
+ "unicode-segmentation",
+]
+
+[[package]]
+name = "indexmap"
+version = "1.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "824845a0bf897a9042383849b02c1bc219c2383772efcd5c6f9766fa4b81aef3"
+dependencies = [
+ "autocfg",
+ "hashbrown",
+]
+
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+
 [[package]]
 name = "libc"
 version = "0.2.95"
@@ -41,10 +107,59 @@ dependencies = [
 name = "opentally"
 version = "0.1.0"
 dependencies = [
+ "clap",
  "num-traits",
  "rug",
 ]
 
+[[package]]
+name = "os_str_bytes"
+version = "2.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "afb2e1c3ee07430c2cf76151675e583e0f19985fa6efae47d6848a3e2c824f85"
+
+[[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-macro2"
+version = "1.0.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0d8caf72986c1a598726adc988bb5984792ef84f5ee5aa50209145ee8077038"
+dependencies = [
+ "unicode-xid",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3d0b9745dc2debf507c8422de05d7226cc1f0644216dfdfead988f9b1ab32a7"
+dependencies = [
+ "proc-macro2",
+]
+
 [[package]]
 name = "rug"
 version = "1.12.0"
@@ -56,6 +171,56 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "syn"
+version = "1.0.72"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1e8cdbefb79a9a5a65e0db8b47b723ee907b7c7f8496c76a1770b5c310bab82"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-xid",
+]
+
+[[package]]
+name = "textwrap"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "203008d98caf094106cfaba70acfed15e18ed3ddb7d94e49baec153a2b462789"
+dependencies = [
+ "unicode-width",
+]
+
+[[package]]
+name = "unicode-segmentation"
+version = "1.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bb0d2e7be6ae3a5fa87eed5fb451aff96f2573d2694942e40543ae0bbe19c796"
+
+[[package]]
+name = "unicode-width"
+version = "0.1.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9337591893a19b88d8d87f2cec1e73fad5cdfd10e5a6f349f498ad6ea2ffb1e3"
+
+[[package]]
+name = "unicode-xid"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
+
+[[package]]
+name = "vec_map"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1bddf1187be692e79c5ffeab891132dfb0f236ed36a43c7ed39f1165ee20191"
+
+[[package]]
+name = "version_check"
+version = "0.9.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5fecdca9a5291cc2b8dcf7dc02453fee791a280f3743cb0905f8822ae463b3fe"
+
 [[package]]
 name = "winapi"
 version = "0.3.9"

Cargo.toml

@@ -11,3 +11,8 @@ num-traits = "0.2"
 version = "1.12"
 default-features = false
 features = ["integer", "rational", "float"]
+
+[dependencies.clap]
+version = "3.0.0-beta.2"
+default-features = false
+features = ["std", "derive"]

src/main.rs

@@ -22,13 +22,33 @@ mod stv;
 use crate::election::{CandidateState, CountState, CountStateOrRef, Election, StageResult};
 use crate::numbers::{Number, NumType};
 
-use std::env;
+use clap::Clap;
+
 use std::fs::File;
 use std::io::{self, BufRead};
 
-const DECIMAL_PLACES: usize = 0;
+#[derive(Clap)]
+struct Opts {
+	#[clap(subcommand)]
+	command: Command,
+}
 
-fn print_stage<N: Number>(stage_num: usize, result: &StageResult<N>) {
+#[derive(Clap)]
+enum Command {
+	STV(STV),
+}
+
+/// Count a single transferable vote (STV) election
+#[derive(Clap)]
+struct STV {
+	/// Path to the BLT file to be counted
+	filename: String,
+	/// Print votes to specified decimal places in results report
+	#[clap(long, default_value="2")]
+	pp_decimals: usize,
+}
+
+fn print_stage<N: Number>(stage_num: usize, result: &StageResult<N>, cmd_opts: &STV) {
 	println!("{}. {}", stage_num, result.title);
 	println!("{}", result.logs.join(" "));
 	
@@ -41,27 +61,28 @@ fn print_stage<N: Number>(stage_num: usize, result: &StageResult<N>) {
 	//for (candidate, count_card) in candidates.into_iter().rev() {
 	for (candidate, count_card) in candidates {
 		if count_card.state == CandidateState::ELECTED {
-			println!("- {}: {:.dps$} ({:.dps$}) - ELECTED {}", candidate.name, count_card.votes, count_card.transfers, count_card.order_elected, dps=DECIMAL_PLACES);
+			println!("- {}: {:.dps$} ({:.dps$}) - ELECTED {}", candidate.name, count_card.votes, count_card.transfers, count_card.order_elected, dps=cmd_opts.pp_decimals);
 		} else if count_card.state == CandidateState::EXCLUDED {
-			println!("- {}: {:.dps$} ({:.dps$}) - Excluded {}", candidate.name, count_card.votes, count_card.transfers, -count_card.order_elected, dps=DECIMAL_PLACES);
+			println!("- {}: {:.dps$} ({:.dps$}) - Excluded {}", candidate.name, count_card.votes, count_card.transfers, -count_card.order_elected, dps=cmd_opts.pp_decimals);
 		} else {
-			println!("- {}: {:.dps$} ({:.dps$})", candidate.name, count_card.votes, count_card.transfers, dps=DECIMAL_PLACES);
+			println!("- {}: {:.dps$} ({:.dps$})", candidate.name, count_card.votes, count_card.transfers, dps=cmd_opts.pp_decimals);
 		}
 	}
 	
-	println!("Quota: {:.dps$}", result.state.as_ref().quota, dps=DECIMAL_PLACES);
+	println!("Quota: {:.dps$}", result.state.as_ref().quota, dps=cmd_opts.pp_decimals);
 	
 	println!("");
 }
 
 fn main() {
-	// Read arguments
-	let file_name = env::args().skip(1).next().expect("First argument must be path to BLT file");
-	
 	let should_clone_state = false;
 	
+	// Read arguments
+	let opts: Opts = Opts::parse();
+	let Command::STV(cmd_opts) = opts.command;
+	
 	// Read BLT file
-	let file = File::open(file_name).expect("IO Error");
+	let file = File::open(&cmd_opts.filename).expect("IO Error");
 	let lines = io::BufReader::new(file).lines();
 	let election: Election<NumType> = Election::from_blt(lines);
 	
@@ -80,7 +101,7 @@ fn main() {
 		logs: vec!["First preferences distributed."],
 		state: if should_clone_state { CountStateOrRef::State(state.clone()) } else { CountStateOrRef::Ref(&state) },
 	};
-	print_stage(1, &result);
+	print_stage(1, &result, &cmd_opts);
 	
 	let mut stage_num = 1;
 	
@@ -101,7 +122,7 @@ fn main() {
 				logs: vec!["Continuing exclusion."],
 				state: if should_clone_state { CountStateOrRef::State(state.clone()) } else { CountStateOrRef::Ref(&state) },
 			};
-			print_stage(stage_num, &result);
+			print_stage(stage_num, &result, &cmd_opts);
 			continue;
 		}
 		
@@ -113,7 +134,7 @@ fn main() {
 				logs: vec!["Surplus distributed."],
 				state: if should_clone_state { CountStateOrRef::State(state.clone()) } else { CountStateOrRef::Ref(&state) },
 			};
-			print_stage(stage_num, &result);
+			print_stage(stage_num, &result, &cmd_opts);
 			continue;
 		}
 		
@@ -125,7 +146,7 @@ fn main() {
 				logs: vec!["Bulk election."],
 				state: if should_clone_state { CountStateOrRef::State(state.clone()) } else { CountStateOrRef::Ref(&state) },
 			};
-			print_stage(stage_num, &result);
+			print_stage(stage_num, &result, &cmd_opts);
 			continue;
 		}
 		
@@ -137,7 +158,7 @@ fn main() {
 				logs: vec!["Candidate excluded."],
 				state: if should_clone_state { CountStateOrRef::State(state.clone()) } else { CountStateOrRef::Ref(&state) },
 			};
-			print_stage(stage_num, &result);
+			print_stage(stage_num, &result, &cmd_opts);
 			continue;
 		}