Implement prime testing.

I thought this would be necessary in order to add to the primes_list...
not sure why I'm wrong.

.gitignore

@@ -1 +1,2 @@
 /target
+/indivisible.1.gz

.gitlab-ci.yml

@@ -1,21 +0,0 @@
-image: "rust:latest"
-
-stages:
-  - build
-  - test
-
-build-job:
-  stage: build
-  artifacts:
-    paths:
-      - target/release/indivisible
-  script:
-    - cargo build --release
-
-test-job:
-  stage: test
-  script:
-    - ./test.sh
-
-include:
-  - template: Security/License-Scanning.gitlab-ci.yml

Cargo.lock

@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "ansi_term"
@@ -22,24 +22,12 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "autocfg"
-version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
-
 [[package]]
 name = "bitflags"
 version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
 
-[[package]]
-name = "cfg-if"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
-
 [[package]]
 name = "clap"
 version = "2.33.3"
@@ -55,56 +43,6 @@ dependencies = [
  "vec_map",
 ]
 
-[[package]]
-name = "crossbeam-channel"
-version = "0.5.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e54ea8bc3fb1ee042f5aace6e3c6e025d3874866da222930f70ce62aceba0bfa"
-dependencies = [
- "cfg-if",
- "crossbeam-utils",
-]
-
-[[package]]
-name = "crossbeam-deque"
-version = "0.8.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6455c0ca19f0d2fbf751b908d5c55c1f5cbc65e03c4225427254b46890bdde1e"
-dependencies = [
- "cfg-if",
- "crossbeam-epoch",
- "crossbeam-utils",
-]
-
-[[package]]
-name = "crossbeam-epoch"
-version = "0.9.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c00d6d2ea26e8b151d99093005cb442fb9a37aeaca582a03ec70946f49ab5ed9"
-dependencies = [
- "cfg-if",
- "crossbeam-utils",
- "lazy_static",
- "memoffset",
- "scopeguard",
-]
-
-[[package]]
-name = "crossbeam-utils"
-version = "0.8.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b5e5bed1f1c269533fa816a0a5492b3545209a205ca1a54842be180eb63a16a6"
-dependencies = [
- "cfg-if",
- "lazy_static",
-]
-
-[[package]]
-name = "either"
-version = "1.6.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e78d4f1cc4ae33bbfc157ed5d5a5ef3bc29227303d595861deb238fcec4e9457"
-
 [[package]]
 name = "heck"
 version = "0.3.2"
@@ -127,7 +65,6 @@ dependencies = [
 name = "indivisible"
 version = "2.0.0"
 dependencies = [
- "rayon",
  "structopt",
 ]
 
@@ -143,25 +80,6 @@ version = "0.2.87"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "265d751d31d6780a3f956bb5b8022feba2d94eeee5a84ba64f4212eedca42213"
 
-[[package]]
-name = "memoffset"
-version = "0.6.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5aa361d4faea93603064a027415f07bd8e1d5c88c9fbf68bf56a285428fd79ce"
-dependencies = [
- "autocfg",
-]
-
-[[package]]
-name = "num_cpus"
-version = "1.13.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "19e64526ebdee182341572e50e9ad03965aa510cd94427a4549448f285e957a1"
-dependencies = [
- "hermit-abi",
- "libc",
-]
-
 [[package]]
 name = "proc-macro-error"
 version = "1.0.4"
@@ -204,37 +122,6 @@ dependencies = [
  "proc-macro2",
 ]
 
-[[package]]
-name = "rayon"
-version = "1.5.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c06aca804d41dbc8ba42dfd964f0d01334eceb64314b9ecf7c5fad5188a06d90"
-dependencies = [
- "autocfg",
- "crossbeam-deque",
- "either",
- "rayon-core",
-]
-
-[[package]]
-name = "rayon-core"
-version = "1.9.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d78120e2c850279833f1dd3582f730c4ab53ed95aeaaaa862a2a5c71b1656d8e"
-dependencies = [
- "crossbeam-channel",
- "crossbeam-deque",
- "crossbeam-utils",
- "lazy_static",
- "num_cpus",
-]
-
-[[package]]
-name = "scopeguard"
-version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
-
 [[package]]
 name = "strsim"
 version = "0.8.0"

Cargo.toml

@@ -6,10 +6,9 @@ description = "A prime number generator and tester"
 edition = "2018"
 readme = "README"
 license = "GPL-3.0"
-keywords = ["primes", "math"]
+keywords = [ "primes", "math" ]
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
 structopt = "0.3.13"
-rayon = "1.5"

TODO

@@ -1,6 +0,0 @@
-============
-*** TODO ***
-============
-Technical:
- - Use bigints (maybe GMP or another similar library)
- - Parallelize computations

install

@@ -6,11 +6,12 @@ then
 	exit 1
 fi
 
-PREFIX="/usr/local"
+PREFIX="${PREFIX:-/usr/local}"
 
 echo "Installing ./target/release/indivisible to $PREFIX/bin/"
-install -m 755 ./target/release/indivisible $PREFIX/bin/
-gzip -c indivisible.1 > indivisible.1.gz
+install -Dm755 ./target/release/indivisible "$PREFIX/bin/indivisible"
+gzip -k indivisible.1
 echo "Installing manpage to $PREFIX/share/man/man1/"
-install -m 644 indivisible.1.gz $PREFIX/share/man/man1/
+install -Dm644 ./indivisible.1.gz "$PREFIX/share/man/man1/indivisible.1.gz"
+# clean up compressed file
 rm indivisible.1.gz

src/candidate.rs

@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2025  Nicolás Ortega Froysa <nicolas@ortegas.org>
+ * Author: Nicolás Ortega Froysa <nicolas@ortegas.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+pub struct CandidateGenerator {
+	base:u64,
+	first_use:bool,
+}
+
+impl CandidateGenerator {
+	pub fn new() -> CandidateGenerator {
+		CandidateGenerator {
+			base: 0,
+			first_use: true,
+		}
+	}
+
+	pub fn next(&mut self) -> u64 {
+		/*
+		 * All primes, except 2 and 3, will be equal to (n * 6 ± 1). This avoids
+		 * multiples of three, optimizing our counting.
+		 */
+		let val;
+
+		if self.base != 0 {
+			if self.first_use {
+				val = self.base - 1;
+			} else {
+				val = self.base + 1;
+			}
+		} else {
+			if self.first_use {
+				val = 2;
+			} else {
+				val = 3;
+			}
+		}
+
+		if self.first_use {
+			self.first_use = false;
+		} else {
+			self.first_use = true;
+			self.base += 6;
+		}
+
+		val
+	}
+}

src/main.rs

@@ -1,6 +1,6 @@
 /*
- * Copyright (C) 2021  Ortega Froysa, Nicolás <nicolas@ortegas.org>
- * Author: Ortega Froysa, Nicolás <nicolas@ortegas.org>
+ * Copyright (C) 2025  Nicolás Ortega Froysa <nicolas@ortegas.org>
+ * Author: Nicolás Ortega Froysa <nicolas@ortegas.org>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -16,142 +16,105 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-use structopt::StructOpt;
-use std::path::PathBuf;
+use std::cell::RefCell;
+use std::collections::VecDeque;
 use std::fs::File;
 use std::io::{BufRead, BufReader};
-use std::collections::VecDeque;
+use std::path::PathBuf;
+use std::process;
+use std::rc::Rc;
+use structopt::StructOpt;
 
-mod test;
+mod candidate;
+use candidate::CandidateGenerator;
+mod worker;
 
 #[derive(StructOpt)]
 #[structopt(about = "A prime number generator and tester.")]
-struct Opt
-{
+struct Opt {
 	#[structopt(short, long, help = "Print all found primes")]
 	verbose:bool,
 	#[structopt(short, long, name = "FILE", help = "Import prime numbers from FILE")]
 	import:Option<PathBuf>,
-	#[structopt(short, long, help = "Test if n is prime instead of generation")]
+	#[structopt(short, long, help = "Test if num is prime instead of generation")]
 	test:bool,
-	#[structopt(help = "Ordinal of the prime to generate")]
-	n:u64,
+	#[structopt(help = "Ordinal of the prime to generate or number to test for primality")]
+	num:u64,
+	#[structopt(short, long, name = "n", help = "Number of threads to spawn")]
+	jobs:Option<u64>,
 }
 
-fn main()
-{
+fn main() {
 	let opts = Opt::from_args();
 
-	// get the first `n` primes
-	let n = opts.n;
-	let mut primes:VecDeque<u64> = VecDeque::new();
+	let primes_list = Rc::new(RefCell::new(VecDeque::<u64>::new()));
 
-	if opts.import.is_some()
-	{
+	if opts.import.is_some() {
 		let in_file = File::open(opts.import.unwrap()).unwrap();
 		let reader = BufReader::new(in_file);
-		reader.lines().into_iter().for_each(|x| {
-			primes.push_back(x.unwrap().parse().unwrap());
-		});
-	}
-
-	if opts.test
-	{
-		let mut res:bool;
-		// if no primes were imported, test from beginning (2)
-		if primes.len() == 0
-		{
-			res = test::is_prime(n);
-		}
-		// `n` should be in `primes` if the last prime is larger than `n`
-		else if primes.back().unwrap() >= &(n)
-		{
-			res = primes.contains(&(n));
-		}
-		// we can memory test `n` if the last prime is >= sqrt(n)
-		else if primes.back().unwrap() >= &((n as f64).sqrt() as u64)
-		{
-			res = test::is_prime_mem(n, &primes)
-		}
-		/*
-		 * if we have less primes than sqrt(n) then we can test all those
-		 * prior to the last prime in the list, and then begin testing odd
-		 * numbers.
-		 */
-		else
-		{
-			res = test::is_prime_mem(n, &primes);
-			if res
-			{
-				res = test::is_prime_f(n, primes.back().unwrap() + 2);
+		for p in reader.lines().into_iter() {
+			primes_list.borrow_mut().push_back(p.unwrap().parse().unwrap());
 		}
 	}
 
-		if res
-		{
-			if opts.verbose
-			{
-				println!("true");
-			}
-			std::process::exit(0);
-		}
-		else
-		{
-			if opts.verbose
-			{
-				println!("false");
-			}
-			std::process::exit(1);
-		}
-	}
-	else
-	{
-		// if `primes` already contains the nth prime, print it
-		if primes.len() >= n as usize
-		{
-			println!("{}", primes.get((n as usize) - 1).unwrap());
-		}
-		else
-		{
-			let mut candidate:u64;
+	let jobs = match opts.jobs {
+		Some(n) => n,
+		None => 1, // TODO: use number of CPUs
+	};
 
-			if primes.len() == 0
-			{
-				// assume 2 as a prime
-				primes.push_back(2);
-				if opts.verbose
-				{
-					println!("{}", 2);
-				}
-				candidate = 3;
-			}
-			else if primes.len() == 1
-			{
-				candidate = 3;
-			}
-			else
-			{
-				candidate = *primes.back().unwrap() + 2;
+	if opts.num == 0 {
+		eprintln!("Invalid value for num: {}", opts.num);
+		process::exit(1);
 	}
 
-			while primes.len() < n as usize
-			{
-				if test::is_prime_mem(candidate, &primes)
-				{
-					primes.push_back(candidate);
-					if opts.verbose
-					{
-						println!("{}", candidate);
+	if opts.test && *primes_list.borrow().back().unwrap_or(&0) >= opts.num {
+		for i in primes_list.borrow().iter() {
+			if *i == opts.num {
+				process::exit(0)
+			}
+		}
+		process::exit(1)
+	} else if !opts.test && primes_list.borrow().len() >= opts.num as usize {
+		let res = *primes_list.borrow().get(opts.num as usize).unwrap();
+		println!("{}", res);
+	} else {
+		let mut cand_gen = CandidateGenerator::new();
+
+		loop {
+			let cand = cand_gen.next();
+			if opts.test && cand > opts.num {
+				break;
+			}
+
+			let mut is_prime = true;
+			for p in primes_list.borrow().iter() {
+				if cand % *p == 0 {
+					is_prime = false;
+					break;
 				}
 			}
 
-				candidate += 2;
+			if is_prime {
+				primes_list.borrow_mut().push_back(cand);
+				if opts.verbose {
+					println!("{}", cand);
 				}
 
-			if !opts.verbose
-			{
-				println!("{}", primes.get((n as usize) - 1).unwrap());
+				if !opts.test && primes_list.borrow().len() == opts.num as usize {
+					break;
 				}
 			}
 		}
+
+		if opts.test {
+			if *primes_list.borrow().back().unwrap() == opts.num {
+				process::exit(0)
+			} else {
+				process::exit(1)
+			}
+		} else if !opts.verbose {
+			let last_prime = *primes_list.borrow().back().unwrap();
+			println!("{}", last_prime);
+		}
+	}
 }

src/test.rs

@@ -1,68 +0,0 @@
-/*
- * Copyright (C) 2021  Ortega Froysa, Nicolás <nicolas@ortegas.org>
- * Author: Ortega Froysa, Nicolás <nicolas@ortegas.org>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-use std::collections::VecDeque;
-use rayon::prelude::*;
-
-pub fn is_prime_f(n:u64, b:u64) -> bool
-{
-	assert_ne!(b, 0);
-	assert_ne!(b, 1);
-
-	if n == 1
-	{
-		return false;
-	}
-
-	let mut start = b;
-	if start == 2
-	{
-		if n % 2 == 0
-		{
-			return false;
-		}
-		else
-		{
-			start += 1;
-		}
-	}
-	// skip even numbers
-	else if start % 2 == 0
-	{
-		start += 1;
-	}
-
-	let limit = (n as f64).sqrt() as u64 + 1;
-	let composite = (start..limit).step_by(2).collect::<Vec<u64>>()
-		.par_iter().any(|x| n % x == 0);
-	return !composite;
-}
-
-pub fn is_prime(n:u64) -> bool
-{
-	return is_prime_f(n, 2);
-}
-
-pub fn is_prime_mem(n:u64, primes:&VecDeque<u64>) -> bool
-{
-	let limit = (n as f64).sqrt() as u64;
-	let pp = primes.partition_point(|x| *x < limit);
-	//let composite = primes.par_iter().take(pp+1).any(|x| n % *x == 0);
-	let composite = primes.iter().take(pp+1).any(|x| n % *x == 0);
-	return !composite;
-}

src/worker.rs

@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2025  Nicolás Ortega Froysa <nicolas@ortegas.org>
+ * Author: Nicolás Ortega Froysa <nicolas@ortegas.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+use std::cell::RefCell;
+use std::collections::VecDeque;
+use std::rc::Rc;
+
+pub struct Worker {
+	primes_list:Rc<RefCell<VecDeque<u64>>>,
+}
+
+impl Worker {
+	pub fn new(primes_list:Rc<RefCell<VecDeque<u64>>>) -> Worker {
+		Worker {
+			primes_list,
+		}
+	}
+
+	pub fn run(&mut self) {
+	}
+}

test.sh

@@ -1,28 +1,50 @@
 #!/bin/bash
 
-echo -n "Prime finding..."
-if [[ $(./target/release/indivisible 5) == 11 ]]
+DEBUG_BIN="./target/debug/indivisible"
+RELEASE_BIN="./target/release/indivisible"
+
+if [ -f "$DEBUG_BIN" ]
 then
-	echo " pass"
+	BINARY="$DEBUG_BIN"
+elif [ -f "$RELEASE_BIN" ]
+then
+	BINARY="$RELEASE_BIN"
 else
-	echo " FAIL"
+	>&2 echo "No valid binary found. Please compile the project."
 	exit 1
 fi
 
-echo -n "Positive prime test..."
-if ./target/release/indivisible -t 11
+tests=0
+passed=0
+
+((tests++))
+echo -n "${tests}: Find 5th prime number..."
+if [[ $("$BINARY" 5) == 11 ]]
 then
 	echo " pass"
+	((passed++))
 else
 	echo " FAIL"
-	exit 1
 fi
 
-echo -n "Negative prime test..."
-if ! ./target/release/indivisible -t 9
+((tests++))
+echo -n "${tests}: 11 is prime..."
+if "$BINARY" -t 11
 then
 	echo " pass"
+	((passed++))
 else
 	echo " FAIL"
-	exit 1
 fi
+
+((tests++))
+echo -n "${tests}: 9 is not prime..."
+if ! "$BINARY" -t 9
+then
+	echo " pass"
+	((passed++))
+else
+	echo " FAIL"
+fi
+
+echo "Results: $passed/$tests"

uninstall

@@ -1,6 +1,6 @@
 #!/bin/sh
-PREFIX="/usr/local"
+PREFIX="${PREFIX:-/usr/local}"
 echo "Remove $PREFIX/bin/indivisible"
-rm -f $PREFIX/bin/indivisible
+rm -f "$PREFIX/bin/indivisible"
 echo "Remove $PREFIX/local/man/man1/indivisible.1.gz"
-rm -f $PREFIX/local/man/man1/indivisible.1.gz
+rm -f "$PREFIX/share/man/man1/indivisible.1.gz"