.gitignore

@@ -1,6 +1,5 @@
 # Generated by Nix
 /.pre-commit-config.yaml
-/result
 
 # Meson
 /build

.woodpecker/check.yml

@@ -1,31 +0,0 @@
-labels:
-  type: exec
-
-steps:
-- name: flake check
-  image: bash
-  commands:
-  - nix flake check
-
-- name: package check
-  image: bash
-  commands:
-  - nix build
-
-- name: notify
-  image: bash
-  secrets:
-  - source: matrix_roomid
-    target: room
-  - source: matrix_username
-    target: user
-  - source: matrix_password
-    target: pass
-  - source: matrix_homeserver
-    target: address
-  commands:
-  - nix run github:ambroisie/matrix-notifier
-  when:
-    status:
-    - failure
-    - success

CMakeLists.txt

@@ -1,18 +0,0 @@
-cmake_minimum_required(VERSION 3.10)
-project(abacus VERSION 0.0.0 LANGUAGES CXX)
-enable_testing()
-
-add_library(common_options INTERFACE)
-target_compile_features(common_options INTERFACE
-  cxx_std_20
-)
-target_compile_options(common_options INTERFACE
-  -Wall
-  -Wextra
-)
-target_include_directories(common_options INTERFACE
-  src
-)
-
-add_subdirectory(src)
-add_subdirectory(tests)

LICENSE

@@ -1,21 +0,0 @@
-MIT License
-
-Copyright (c) [year] [fullname]
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.

flake.nix

@@ -29,40 +29,9 @@
   };
 
   outputs = { self, futils, nixpkgs, pre-commit-hooks }:
-    {
-      overlays.default = final: prev: {
-        abacus = final.stdenv.mkDerivation {
-          pname = "abacus";
-          version = "0.0.0";
-
-          src = self;
-
-          nativeBuildInputs = with final; [
-            bison
-            cmake
-            flex
-            ninja
-            pkg-config
-          ];
-
-          checkInputs = with final; [
-            gtest
-          ];
-
-          doCheck = true;
-
-          meta = with final.lib; {
-            description = "A simple calculator using big numbers";
-            homepage = "https://gitea.belanyi.fr/ambroisie/abacus";
-            license = licenses.mit;
-            maintainers = [ ambroisie ];
-            platforms = platforms.unix;
-          };
-        };
-      };
-    } // futils.lib.eachDefaultSystem (system:
+    futils.lib.eachDefaultSystem (system:
       let
-        pkgs = import nixpkgs { inherit system; overlays = [ self.overlays.default ]; };
+        pkgs = import nixpkgs { inherit system; };
       in
       {
         checks = {
@@ -87,17 +56,44 @@
           };
         };
 
-        devShells.default = pkgs.mkShell {
-          inputsFrom = with self.packages.${system}; [
-            abacus
-          ];
+        defaultPackage = self.packages.${system}.abacus;
+
+        devShell = pkgs.mkShell {
+          inherit (self.defaultPackage.${system})
+            buildInputs
+            nativeBuildInputs
+            ;
 
           inherit (self.checks.${system}.pre-commit) shellHook;
         };
 
         packages = futils.lib.flattenTree {
-          inherit (pkgs) abacus;
-          default = pkgs.abacus;
+          abacus = pkgs.stdenv.mkDerivation {
+            pname = "abacus";
+            version = "0.0.0";
+
+            src = self;
+
+            nativeBuildInputs = with pkgs; [
+              bison
+              flex
+              meson
+              ninja
+              pkg-config
+            ];
+
+            buildInputs = with pkgs; [
+              gtest
+            ];
+
+            meta = with pkgs.lib; {
+              description = "A simple calculator using big numbers";
+              homepage = "https://gitea.belanyi.fr/ambroisie/abacus";
+              license = licenses.mit;
+              maintainers = [ ambroisie ];
+              platforms = platforms.unix;
+            };
+          };
         };
       });
 }

meson.build

@@ -0,0 +1,13 @@
+project(
+  'abacus',
+  'cpp',
+  version: '0.0.0',
+  license: 'MIT',
+  default_options: [
+    'warning_level=3',
+    'cpp_std=c++17',
+  ],
+)
+
+subdir('src')
+subdir('tests')

src/CMakeLists.txt

@@ -1,12 +0,0 @@
-add_executable(abacus abacus.cc)
-target_link_libraries(abacus PRIVATE common_options)
-
-add_subdirectory(bignum)
-add_subdirectory(parse)
-
-target_link_libraries(abacus PRIVATE
-  bignum
-  parse
-)
-
-install(TARGETS abacus)

src/abacus.cc

@@ -1,4 +1,4 @@
-#include "parse/parser-driver.hh"
+#include "parser-driver.hh" // FIXME: I would like `parse/parser-driver.hh` path instead...
 
 int main() {
     abacus::parse::ParserDriver driver{};

src/bignum/CMakeLists.txt

@@ -1,5 +0,0 @@
-add_library(bignum STATIC
-  bignum.cc
-  bignum.hh
-)
-target_link_libraries(bignum PRIVATE common_options)

src/bignum/bignum.cc

@@ -3,7 +3,6 @@
 #include <algorithm>
 #include <iostream>
 #include <iterator>
-#include <span>
 
 #include <cassert>
 #include <cmath>
@@ -25,46 +24,12 @@ bool do_less_than(digits_type const& lhs, digits_type const& rhs) {
                                         rhs.rend());
 }
 
-void trim_leading_zeros(digits_type& num) {
+void do_trim_leading_zeros(digits_type& num) {
     auto const it
         = std::find_if(num.rbegin(), num.rend(), [](auto v) { return v != 0; });
     num.erase(it.base(), num.end());
 }
 
-std::ostream& do_dump(digits_type const& num, std::ostream& out) {
-    std::copy(num.rbegin(), num.rend(), std::ostream_iterator<int>(out));
-    return out;
-}
-
-// More optimised than full-on div_mod
-digits_type do_halve(digits_type num) {
-    assert(num.size() != 0);
-
-    int carry = 0;
-    for (auto i = num.rbegin(); i != num.rend(); ++i) {
-        auto const was_odd = (*i % 2) == 1;
-        *i /= 2;
-        *i += carry;
-        if (was_odd) {
-            carry = BASE / 2;
-        } else {
-            carry = 0;
-        }
-    }
-
-    trim_leading_zeros(num);
-
-    return num;
-}
-
-bool is_odd(digits_type const& num) {
-    if (num.size() == 0) {
-        return false;
-    }
-
-    return (num.front() % 2) == 1;
-}
-
 digits_type do_addition(digits_type const& lhs, digits_type const& rhs) {
     int carry = 0;
     digits_type res;
@@ -83,17 +48,18 @@ digits_type do_addition(digits_type const& lhs, digits_type const& rhs) {
         ++it2;
     }
 
-    auto leftover = [=]() {
-        if (it1 != end1) {
-            return std::span(it1, end1);
-        }
-        return std::span(it2, end2);
-    }();
+    auto it = it1;
+    auto end = end1;
+    if (it1 == end1) {
+        it = it2;
+        end = end2;
+    }
 
-    for (auto value : leftover) {
-        int addition = value + carry;
+    while (it != end) {
+        int addition = *it + carry;
         carry = addition / BASE;
         res.push_back(addition % BASE);
+        ++it;
     }
 
     if (carry != 0) {
@@ -107,7 +73,7 @@ digits_type do_substraction(digits_type const& lhs, digits_type const& rhs) {
     assert(!do_less_than(lhs, rhs));
 
     digits_type complement;
-    auto const take_complement = [](auto num) { return BASE - 1 - num; };
+    auto const take_complement = [](auto num) { return 9 - num; };
     std::transform(lhs.begin(), lhs.end(), std::back_inserter(complement),
                    take_complement);
 
@@ -116,7 +82,7 @@ digits_type do_substraction(digits_type const& lhs, digits_type const& rhs) {
     std::transform(complement.begin(), complement.end(), complement.begin(),
                    take_complement);
 
-    trim_leading_zeros(complement);
+    do_trim_leading_zeros(complement);
 
     return complement;
 }
@@ -144,33 +110,59 @@ std::pair<digits_type, digits_type> do_div_mod(digits_type const& lhs,
         throw std::invalid_argument("attempt to divide by zero");
     }
 
-    digits_type multiple = rhs;
-    digits_type rank;
-    rank.push_back(1);
-
-    while (!do_less_than(lhs, multiple)) {
-        multiple = do_addition(multiple, multiple);
-        rank = do_addition(rank, rank);
-    }
-
     digits_type quotient;
     digits_type remainder = lhs;
 
     while (!do_less_than(remainder, rhs)) {
-        while (do_less_than(remainder, multiple)) {
-            multiple = do_halve(multiple);
-            rank = do_halve(rank);
+        // TODO: use `do_halve` to back down after calculate highest multiple
+        digits_type multiple = rhs;
+        digits_type rank;
+        rank.push_back(1);
+
+        digits_type prev_multiple = multiple;
+        digits_type prev_rank = rank;
+
+        while (!do_less_than(remainder, multiple)) {
+            prev_multiple = multiple;
+            prev_rank = rank;
+            multiple = do_addition(multiple, multiple);
+            rank = do_addition(rank, rank);
         }
 
-        assert(!do_less_than(multiple, rhs));
-
-        quotient = do_addition(quotient, rank);
-        remainder = do_substraction(remainder, multiple);
+        quotient = do_addition(quotient, prev_rank);
+        remainder = do_substraction(remainder, prev_multiple);
     }
 
     return std::make_pair(quotient, remainder);
 }
 
+// More optimised than full-on div_mod
+digits_type do_halve(digits_type num) {
+    assert(num.size() != 0);
+
+    int carry = 0;
+    for (auto i = num.rbegin(); i != num.rend(); ++i) {
+        auto const was_odd = (*i % 2) == 1;
+        *i /= 2;
+        *i += carry;
+        if (was_odd) {
+            carry = BASE / 2;
+        }
+    }
+
+    do_trim_leading_zeros(num);
+
+    return num;
+}
+
+bool is_odd(digits_type const& num) {
+    if (num.size() == 0) {
+        return false;
+    }
+
+    return (num.front() % 2) == 1;
+}
+
 digits_type do_pow(digits_type lhs, digits_type rhs) {
     assert(rhs.size() != 0);
 
@@ -234,8 +226,10 @@ std::ostream& BigNum::dump(std::ostream& out) const {
     if (is_negative()) {
         out << '-';
     }
+    std::copy(digits_.rbegin(), digits_.rend(),
+              std::ostream_iterator<int>(out));
 
-    return do_dump(digits_, out);
+    return out;
 }
 
 std::istream& BigNum::read(std::istream& in) {
@@ -363,15 +357,11 @@ bool BigNum::less_than(BigNum const& rhs) const {
         return sign_ < rhs.sign_;
     }
 
-    if (is_positive()) {
-        return do_less_than(digits_, rhs.digits_);
-    } else {
-        return do_less_than(rhs.digits_, digits_);
-    }
+    return do_less_than(digits_, rhs.digits_);
 }
 
 void BigNum::canonicalize() {
-    trim_leading_zeros(digits_);
+    do_trim_leading_zeros(digits_);
 
     if (digits_.size() == 0) {
         sign_ = 0;
@@ -385,15 +375,15 @@ bool BigNum::is_canonicalized() const {
         return sign_ == 0;
     }
 
-    // `back` is valid since there is at least one element
-    auto const has_leading_zero = digits_.back() == 0;
-    if (has_leading_zero) {
+    auto const leading_zeros = std::find_if(digits_.rbegin(), digits_.rend(),
+                                            [](auto v) { return v != 0; });
+    if (leading_zeros != digits_.rbegin()) {
         return false;
     }
 
-    auto const has_overflow = std::any_of(digits_.begin(), digits_.end(),
-                                          [](auto v) { return v >= BASE; });
-    if (has_overflow) {
+    auto const overflow = std::find_if(digits_.begin(), digits_.end(),
+                                       [](auto v) { return v >= BASE; });
+    if (overflow != digits_.end()) {
         return false;
     }
 
@@ -423,8 +413,8 @@ std::pair<BigNum, BigNum> div_mod(BigNum const& lhs, BigNum const& rhs) {
         return std::make_pair(BigNum(), BigNum());
     }
 
-    auto quotient = BigNum(0);
-    auto remainder = BigNum(0);
+    BigNum quotient;
+    BigNum remainder;
 
     std::tie(quotient.digits_, remainder.digits_)
         = do_div_mod(lhs.digits_, rhs.digits_);
@@ -449,7 +439,7 @@ BigNum pow(BigNum const& lhs, BigNum const& rhs) {
         return BigNum();
     }
 
-    auto res = BigNum(0);
+    BigNum res;
     res.digits_ = do_pow(lhs.digits_, rhs.digits_);
 
     res.sign_ = is_odd(rhs.digits_) ? lhs.sign_ : 1;
@@ -468,7 +458,7 @@ BigNum sqrt(BigNum const& num) {
             "attempt to take the square root of a negative number");
     }
 
-    auto res = BigNum(0);
+    BigNum res;
 
     res.digits_ = do_sqrt(num.digits_);
     res.sign_ = 1;
@@ -478,46 +468,4 @@ BigNum sqrt(BigNum const& num) {
     return res;
 }
 
-BigNum log2(BigNum const& num) {
-    assert(num.is_canonicalized());
-
-    if (num.is_zero()) {
-        throw std::invalid_argument("attempt to take the log2 of zero");
-    } else if (num.is_negative()) {
-        throw std::invalid_argument(
-            "attempt to take the log2 of a negative number");
-    }
-
-    auto tmp = num;
-    auto res = BigNum(0);
-    auto one = BigNum(1);
-
-    while (tmp > one) {
-        tmp.digits_ = do_halve(tmp.digits_);
-        res += one;
-    }
-
-    assert(res.is_canonicalized());
-
-    return res;
-}
-
-BigNum log10(BigNum const& num) {
-    assert(num.is_canonicalized());
-    assert(BASE == 10);
-
-    if (num.is_zero()) {
-        throw std::invalid_argument("attempt to take the log10 of zero");
-    } else if (num.is_negative()) {
-        throw std::invalid_argument(
-            "attempt to take the log10 of a negative number");
-    }
-
-    auto res = BigNum(num.digits_.size() - 1);
-
-    assert(res.is_canonicalized());
-
-    return res;
-}
-
 } // namespace abacus::bignum

src/bignum/bignum.hh

@@ -91,10 +91,6 @@ public:
 
     friend BigNum sqrt(BigNum const& num);
 
-    friend BigNum log2(BigNum const& num);
-
-    friend BigNum log10(BigNum const& num);
-
     friend bool operator==(BigNum const& lhs, BigNum const& rhs) {
         return lhs.equal(rhs);
     }
@@ -119,10 +115,6 @@ public:
         return !(lhs < rhs);
     }
 
-    explicit operator bool() {
-        return !is_zero();
-    }
-
     bool is_zero() const;
     bool is_positive() const;
     bool is_negative() const;

src/bignum/meson.build

@@ -0,0 +1,16 @@
+bignum_sources = files(
+  'bignum.cc',
+  'bignum.hh',
+)
+
+bignum_inc = include_directories('.')
+
+bignum_lib = library(
+  'bignum',
+  sources: bignum_sources,
+)
+
+bignum = declare_dependency(
+  link_with: bignum_lib,
+  include_directories: bignum_inc,
+)

src/meson.build

@@ -0,0 +1,15 @@
+abacus_sources = files(
+  'abacus.cc',
+)
+
+subdir('bignum')
+subdir('parse')
+
+abacus = executable(
+  'abacus',
+  sources: abacus_sources,
+  dependencies: [
+    bignum,
+    parse,
+  ],
+)

src/parse/CMakeLists.txt

@@ -1,23 +0,0 @@
-find_package(BISON REQUIRED)
-find_package(FLEX REQUIRED)
-
-bison_target(parser_sources parser.yy ${CMAKE_CURRENT_BINARY_DIR}/parser.cc DEFINES_FILE ${CMAKE_CURRENT_BINARY_DIR}/parser.hh)
-flex_target(scanner_sources scanner.ll  ${CMAKE_CURRENT_BINARY_DIR}/scanner.cc)
-add_flex_bison_dependency(scanner_sources parser_sources)
-
-add_library(parse STATIC
-  parser-driver.cc
-  parser-driver.hh
-  ${BISON_parser_sources_OUTPUTS}
-  ${FLEX_scanner_sources_OUTPUTS}
-)
-target_link_libraries(parse PRIVATE common_options)
-
-target_link_libraries(parse PRIVATE
-  bignum
-)
-
-target_include_directories(parse PUBLIC
-  $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>
-  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
-)

src/parse/meson.build

@@ -0,0 +1,48 @@
+flex_binary = find_program('flex', required: true)
+lexer_sources = custom_target(
+  'lexer_sources',
+  input: 'scanner.ll',
+  output: 'scanner.cc',
+  command: [
+    flex_binary,
+    '-o',
+    '@OUTPUT@',
+    '@INPUT@',
+  ],
+)
+
+bison_binary = find_program('bison', required: true)
+parser_sources = custom_target(
+  'parser_sources',
+  input: 'parser.yy',
+  output: [
+    'parser.cc',
+    'parser.hh',
+  ],
+  command: [
+    bison_binary,
+    '@INPUT@',
+    '--output=@OUTPUT0@',
+    '--defines=@OUTPUT1@',
+    '--graph',
+    # FIXME: html output in bison 3.7.90
+  ],
+)
+
+parse_inc = include_directories('.')
+
+parse_lib = library(
+  'parser',
+  'parser-driver.cc',
+  'parser-driver.hh',
+  lexer_sources,
+  parser_sources,
+  dependencies: [
+    bignum,
+  ],
+)
+
+parse = declare_dependency(
+  link_with: parse_lib,
+  include_directories: parse_inc,
+)

src/parse/parser-driver.hh

@@ -4,7 +4,7 @@
 
 #include "parser.hh"
 
-#include "bignum/bignum.hh"
+#include "bignum.hh" // FIXME: I would like `bignum/bignum.hh` path instead...
 
 namespace abacus::parse {
 

src/parse/parser.yy

@@ -36,7 +36,7 @@ namespace abacus::parse {
 class ParserDriver;
 } // namespace abacus::parse
 
-#include "bignum/bignum.hh"
+#include "bignum.hh" // FIXME: I would like `bignum/bignum.hh` path instead...
 }
 
 %code provides {

tests/CMakeLists.txt

@@ -1 +0,0 @@
-add_subdirectory(unit)

tests/meson.build

@@ -0,0 +1 @@
+subdir('unit')

tests/unit/CMakeLists.txt

@@ -1,16 +0,0 @@
-find_package(GTest)
-
-if (${GTest_FOUND})
-include(GoogleTest)
-
-add_executable(bignum_test bignum.cc)
-target_link_libraries(bignum_test PRIVATE common_options)
-
-target_link_libraries(bignum_test PRIVATE
-  bignum
-  GTest::gtest
-  GTest::gtest_main
-)
-
-gtest_discover_tests(bignum_test)
-endif (${GTest_FOUND})

tests/unit/bignum.cc

@@ -2,7 +2,7 @@
 
 #include <gtest/gtest.h>
 
-#include "bignum/bignum.hh"
+#include "bignum.hh"
 
 using namespace abacus::bignum;
 
@@ -68,34 +68,6 @@ TEST(BigNum, comparisons_digits) {
     EXPECT_GT(ten, nine);
 }
 
-TEST(BigNum, comparisons_negative) {
-    auto const zero = BigNum(0);
-    auto const minus_one = BigNum(-1);
-    auto const minus_two = BigNum(-2);
-
-    EXPECT_LT(minus_one, zero);
-    EXPECT_LE(minus_one, zero);
-    EXPECT_LT(minus_two, minus_one);
-    EXPECT_LE(minus_two, minus_one);
-    EXPECT_LE(minus_one, minus_one);
-    EXPECT_GE(minus_two, minus_two);
-
-    EXPECT_GT(zero, minus_one);
-    EXPECT_GE(zero, minus_one);
-    EXPECT_GT(minus_one, minus_two);
-    EXPECT_GE(minus_one, minus_two);
-    EXPECT_GE(minus_one, minus_one);
-    EXPECT_GE(minus_two, minus_two);
-}
-
-TEST(BigNum, comparisons_digits_negative) {
-    auto const minus_nine = BigNum(-9);
-    auto const minus_ten = BigNum(-10);
-
-    EXPECT_LT(minus_ten, minus_nine);
-    EXPECT_GT(minus_nine, minus_ten);
-}
-
 TEST(BigNum, unary) {
     auto const zero = BigNum(0);
     auto const one = BigNum(1);
@@ -404,44 +376,3 @@ TEST(BigNum, sqrt) {
     EXPECT_EQ(sqrt(ninety_nine), nine);
     EXPECT_EQ(sqrt(hundred), ten);
 }
-
-TEST(BigNum, log2) {
-    auto const zero = BigNum(0);
-    auto const one = BigNum(1);
-    auto const two = BigNum(2);
-    auto const three = BigNum(3);
-    auto const four = BigNum(4);
-    auto const five = BigNum(5);
-    auto const seven = BigNum(7);
-    auto const eight = BigNum(8);
-    auto const nine = BigNum(9);
-
-    EXPECT_EQ(log2(one), zero);
-    EXPECT_EQ(log2(two), one);
-    EXPECT_EQ(log2(three), one);
-    EXPECT_EQ(log2(four), two);
-    EXPECT_EQ(log2(five), two);
-    EXPECT_EQ(log2(seven), two);
-    EXPECT_EQ(log2(eight), three);
-    EXPECT_EQ(log2(nine), three);
-}
-
-TEST(BigNum, log10) {
-    auto const zero = BigNum(0);
-    auto const one = BigNum(1);
-    auto const two = BigNum(2);
-    auto const nine = BigNum(9);
-    auto const ten = BigNum(10);
-    auto const eleven = BigNum(11);
-    auto const ninety_nine = BigNum(99);
-    auto const hundred = BigNum(100);
-    auto const hundred_one = BigNum(101);
-
-    EXPECT_EQ(log10(one), zero);
-    EXPECT_EQ(log10(nine), zero);
-    EXPECT_EQ(log10(ten), one);
-    EXPECT_EQ(log10(eleven), one);
-    EXPECT_EQ(log10(ninety_nine), one);
-    EXPECT_EQ(log10(hundred), two);
-    EXPECT_EQ(log10(hundred_one), two);
-}

tests/unit/meson.build

@@ -0,0 +1,26 @@
+gtest = dependency(
+  'gtest',
+  main: true,
+  required: false,
+)
+
+if gtest.found()
+  unit_test_sources = files(
+    'bignum.cc',
+  )
+
+  unit_tests = executable(
+    'unit_tests',
+    sources: unit_test_sources,
+    dependencies: [
+      bignum,
+      gtest,
+    ],
+  )
+
+  test(
+    'unit tests',
+    unit_tests,
+    protocol: 'gtest',
+  )
+endif