more flexible term parsing (#19)

* more flexible term parsing
* update readme
* update deployment scripts

.github/conda/conda_build_config.yaml

@@ -11,7 +11,8 @@ clingo:
 pin_run_as_build:
     clingo: x.x
 
-# from https://github.com/phracker/MacOSX-SDKs
-CONDA_BUILD_SYSROOT:
-    - /opt/MacOSX10.9.sdk # [osx and not arm64]
-    - /opt/MacOSX11.3.sdk # [osx and arm64]
+MACOSX_DEPLOYMENT_TARGET: 10.15  # [osx and not arm64]
+MACOSX_DEPLOYMENT_TARGET: 11.3   # [osx and arm64]
+CONDA_BUILD_SYSROOT:             # [osx]
+    - /opt/MacOSX10.15.sdk       # [osx and not arm64]
+    - /opt/MacOSX11.3.sdk        # [osx and arm64]

.github/deploy.yml

@@ -6,6 +6,9 @@ cibw:
                 m = match(r'#define CLINGOLPX_VERSION "([0-9]+\.[0-9]+\.[0-9]+)"', line)
                 if m is not None:
                     version = m.group(1)
+    macosx_deployment_target:
+        x86_64: 10.15
+        arm64: 10.15
 
 conda:
     package_name:
@@ -15,7 +18,7 @@ conda:
         - 'macos-latest'
         - 'windows-2019'
     macosx-sdk:
-        - 'MacOSX10.9.sdk.tar.xz'
+        - 'MacOSX10.15.sdk.tar.xz'
         - 'MacOSX11.3.sdk.tar.xz'
     channels_release:
         - 'potassco'
@@ -109,10 +112,11 @@ conda:
         pin_run_as_build:
             clingo: x.x
 
-        # from https://github.com/phracker/MacOSX-SDKs
-        CONDA_BUILD_SYSROOT:
-            - /opt/MacOSX10.9.sdk # [osx and not arm64]
-            - /opt/MacOSX11.3.sdk # [osx and arm64]
+        MACOSX_DEPLOYMENT_TARGET: 10.15  # [osx and not arm64]
+        MACOSX_DEPLOYMENT_TARGET: 11.3   # [osx and arm64]
+        CONDA_BUILD_SYSROOT:             # [osx]
+            - /opt/MacOSX10.15.sdk       # [osx and not arm64]
+            - /opt/MacOSX11.3.sdk        # [osx and arm64]
 
 ppa:
     package_name:

.github/workflows/cibuildwheel.yml

@@ -13,7 +13,7 @@ jobs:
     name: Build source distribution
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
 
@@ -28,8 +28,9 @@ jobs:
       - name: Build sdist
         run: pipx run build --sdist
 
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v4
         with:
+          name: cibw-sdist
           path: dist/*.tar.gz
 
   build_wheels:
@@ -78,19 +79,23 @@ jobs:
             name: "cp*-win*"
             env:
               CIBW_BUILD: "cp*-win*"
-          - os: macos-11
-            name: "*-macos_{x86_64,arm64}"
+          - os: macos-13
+            name: "*-macos_x86_64"
             env:
-              CIBW_ARCHS_MACOS: x86_64 arm64
+              MACOSX_DEPLOYMENT_TARGET: "10.15"
+          - os: macos-14
+            name: "*-macos_arm64"
+            env:
+              MACOSX_DEPLOYMENT_TARGET: "10.15"
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
 
       - name: Set up QEMU
         if: runner.os == 'Linux'
-        uses: docker/setup-qemu-action@v2
+        uses: docker/setup-qemu-action@v3
         with:
           platforms: all
 
@@ -103,21 +108,23 @@ jobs:
         run: python .github/adjust_version.py --release
 
       - name: Build wheels
-        uses: pypa/cibuildwheel@v2.19.1
+        uses: pypa/cibuildwheel@v2.20.0
         env: ${{ matrix.cfg.env }}
 
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v4
         with:
+          name: cibw-wheels-${{ matrix.cfg.os }}-${{ strategy.job-index }}
           path: ./wheelhouse/*.whl
 
   upload_pypi:
     needs: [build_wheels, build_sdist]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
         with:
-          name: artifact
+          pattern: cibw-*
           path: dist
+          merge-multiple: true
 
       - uses: pypa/[email protected]
         if: ${{ github.event.inputs.wip == 'true' }}

.github/workflows/conda-dev.yml

@@ -44,8 +44,8 @@ jobs:
       if: ${{ matrix.os == 'macos-latest' }}
       shell: pwsh
       run: |
-        Invoke-WebRequest -Uri 'https://github.com/phracker/MacOSX-SDKs/releases/download/11.3/MacOSX10.9.sdk.tar.xz' -OutFile 'MacOSX10.9.sdk.tar.xz'
-        sudo tar xf MacOSX10.9.sdk.tar.xz -C /opt
+        Invoke-WebRequest -Uri 'https://github.com/phracker/MacOSX-SDKs/releases/download/11.3/MacOSX10.15.sdk.tar.xz' -OutFile 'MacOSX10.15.sdk.tar.xz'
+        sudo tar xf MacOSX10.15.sdk.tar.xz -C /opt
         Invoke-WebRequest -Uri 'https://github.com/phracker/MacOSX-SDKs/releases/download/11.3/MacOSX11.3.sdk.tar.xz' -OutFile 'MacOSX11.3.sdk.tar.xz'
         sudo tar xf MacOSX11.3.sdk.tar.xz -C /opt
 

Makefile

@@ -1,12 +1,14 @@
 BUILD_TYPE:=debug
 CLINGO_DIR:=${HOME}/.local/opt/potassco/$(BUILD_TYPE)/lib/cmake/Clingo
-CXXFLAGS=-Wall -Wextra -Wpedantic -Werror
+CXX=clang++
+CXXFLAGS=-Wall -Wextra -Wpedantic -Werror -stdlib=libc++
 define cmake_options
 -G Ninja \
 -S . \
 -B "build/$(BUILD_TYPE)" \
 -DCMAKE_INSTALL_PREFIX=${HOME}/.local/opt/potassco/$(BUILD_TYPE) \
 -DCMAKE_CXX_FLAGS="$(CXXFLAGS)" \
+-DCMAKE_CXX_COMPILER="$(CXX)" \
 -DClingo_DIR="$(CLINGO_DIR)" \
 -DCLINGOLPX_BUILD_TESTS=On \
 -DCMAKE_EXPORT_COMPILE_COMMANDS=On

README.md

@@ -45,17 +45,25 @@ Note that packages from the [conda-forge] channel offer better performance than
 ## Input format
 
 The system supports `&sum` constraints over rationals with relations among `<=`, `>=`, and `=`.
-The elements of the sum constraints must have form `x`, `-x`, `n*x`, `-n*x`, or `-n/d*x`
-where `x` is a function symbol or tuple, and `n` and `d` are numbers.
-A number has to be either a non negative integer or decimal number in quotes.
+The elements of the sum constraints and terms of guards must be linear expressions.
+Quoted strings can be used to represent decimal numbers of arbitrary precision.
+Terms can be nested using operators `+`, `-`, `*`, `/`.
+Usage of multiplication and division is limited.
+Only expressions of form `c * t`, `t * c`, and `t / c` are accepted
+where `c` must not refer to variables and must be non-zero in the latter case.
+If functions are used as variable names, operators `+`, `-`, `*`, `/` in their arguments are evaluated as well.
+There is no special handling of strings for function arguments though.
 
 For example, the following program is accepted:
 ```
 { x }.
-&sum { x; -y; 2*x; -3*y; 2/3*x; -3/4*y, "0.75"*z } >= 100 :- x.
+&sum { 2*var(1+2) } = "0.3".
+&sum { var(3) } <= 3 * ("0.75"*z) :- x.
+&sum { var(3); (100*y)/2 } <= 0 :- not x.
 ```
 
 Furthermore, `&dom` constraints are supported, which are shortcuts for `&sum` constraints.
+Terms in braces must be numbers and the right-hand-side must be a variable.
 The program
 ```
 { x }.
@@ -68,6 +76,19 @@ is equivalent to
 &sum { x } <= 2.
 ```
 
+Another shortcut (for compatibility with [clingo-dl]) are `&diff` constraints.
+Terms in braces must be variables and the right-hand-side must be a number.
+The same relations as for &sum constraints are accepted. 
+```
+{ x }.
+&diff { a-b } <= 5.
+```
+is equivalent to
+```
+{ x }.
+&sum { a-b } <= 5.
+```
+
 When option `--strict` is passed to the solver, then also strict constraints are supported:
 ```
 { x }.
@@ -140,6 +161,7 @@ Furthermore, note that [IMath] uses the MIT and [FLINT] the LGPL license.
 [IMath]: https://github.com/creachadair/imath
 [cmake]: https://cmake.org
 [clingo]: https://github.com/potassco/clingo
+[clingo-dl]: https://github.com/potassco/clingo-dl
 [conda-forge]: https://conda-forge.org/
 [gperftools]: https://gperftools.github.io/gperftools/cpuprofile.html
 [miniconda]: https://docs.conda.io/en/latest/miniconda.html

libclingo-lpx/src/number_flint.hh

@@ -7,8 +7,10 @@
 
 #include <ios>
 #include <iostream>
+#include <limits>
 #include <memory>
 #include <new>
+#include <optional>
 #include <stdexcept>
 #include <string>
 
@@ -83,6 +85,7 @@ class Integer {
     auto add_mul(Integer const &a, Integer const &b) && -> Integer;
     auto neg() -> Integer &;
     [[nodiscard]] auto impl() const -> fmpz &;
+    [[nodiscard]] auto as_int() const -> std::optional<int>;
 
   private:
     mutable fmpz num_;
@@ -239,6 +242,16 @@ inline auto Integer::neg() -> Integer & {
     return *this;
 }
 
+inline auto Integer::as_int() const -> std::optional<int> {
+    if (fmpz_fits_si(&num_)) {
+        if (auto res = fmpz_get_si(&num_);
+            std::numeric_limits<int>::min() <= res && res <= std::numeric_limits<int>::max()) {
+            return res;
+        }
+    }
+    return std::nullopt;
+}
+
 inline auto Integer::impl() const -> fmpz & { return num_; }
 
 // addition

libclingo-lpx/src/number_imath.hh

@@ -7,8 +7,10 @@
 
 #include <ios>
 #include <iostream>
+#include <limits>
 #include <memory>
 #include <new>
+#include <optional>
 #include <stdexcept>
 #include <string>
 
@@ -83,6 +85,7 @@ class Integer {
     auto add_mul(Integer const &a, Integer const &b) & -> Integer &;
     auto add_mul(Integer const &a, Integer const &b) && -> Integer;
     auto neg() -> Integer &;
+    [[nodiscard]] auto as_int() const -> std::optional<int>;
     [[nodiscard]] auto impl() const -> mpz_t &;
 
   private:
@@ -251,6 +254,16 @@ inline auto Integer::neg() -> Integer & {
     return *this;
 }
 
+inline auto Integer::as_int() const -> std::optional<int> {
+    auto res = mp_small{};
+    if (mp_int_to_int(&num_, &res) == MP_OK) {
+        if (std::numeric_limits<int>::min() <= res && res <= std::numeric_limits<int>::max()) {
+            return res;
+        }
+    }
+    return std::nullopt;
+}
+
 inline auto Integer::impl() const -> mpz_t & { return num_; }
 
 // addition