build Path (#20)

* not good

* construct path

* build path

* fix

* fix

* fix

* fix# Please enter the commit message for your changes. Lines starting

* fix version

---------

Co-authored-by: TANG ZHIXIONG <[email protected]>

Author: district10

.vscode/settings.json

@@ -1,5 +1,6 @@
 {
     "files.associations": {
+        "*.py": "python",
         "variant": "cpp",
         "bitset": "cpp",
         "chrono": "cpp",
@@ -9,6 +10,8 @@
         "set": "cpp",
         "unordered_map": "cpp",
         "thread": "cpp",
-        "__locale": "cpp"
+        "__locale": "cpp",
+        "stdexcept": "cpp",
+        "cmath": "cpp"
     }
 }

docs/conf.py

@@ -58,9 +58,9 @@
 # built documents.
 #
 # The short X.Y version.
-version = '0.1.6'
+version = '0.1.7'
 # The full version, including alpha/beta/rc tags.
-release = '0.1.6'
+release = '0.1.7'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.

pyproject.toml

@@ -5,7 +5,7 @@ build-backend = "scikit_build_core.build"
 
 [project]
 name = "networkx_graph"
-version = "0.1.6"
+version = "0.1.7"
 url = "https://github.com/cubao/networkx-graph"
 description = "Some customized graph algorithms"
 readme = "README.md"

src/main.cpp

@@ -462,6 +462,19 @@ struct DiGraph
     {
         return indexer_.get_id(node);
     }
+    std::optional<std::tuple<int64_t, double>>
+    __node_length(const std::string &node) const
+    {
+        auto nid = __node_id(node);
+        if (!nid) {
+            return {};
+        }
+        auto len = lengths_.find(*nid);
+        if (len == lengths_.end()) {
+            return {};
+        }
+        return std::make_tuple(*nid, len->second);
+    }
     std::string __node_id(int64_t node) const { return indexer_.id(node); }
     std::vector<std::string> __node_ids(const std::vector<int64_t> &nodes) const
     {
@@ -1957,6 +1970,64 @@ PYBIND11_MODULE(_core, m)
         ;
 
     py::class_<Path>(m, "Path", py::module_local(), py::dynamic_attr()) //
+        .def_static(
+            "Build",
+            [](const DiGraph &graph, const std::vector<std::string> &nodes,
+               std::optional<double> start_offset = {},
+               std::optional<double> end_offset = {},
+               std::optional<std::tuple<std::string, Binding>> binding = {})
+                -> Path {
+                if (nodes.empty()) {
+                    throw std::invalid_argument("not any nodes");
+                }
+                std::vector<int64_t> nids;
+                std::vector<double> lengths;
+                const auto N = nodes.size();
+                nids.reserve(N);
+                lengths.reserve(N);
+                for (auto &node : nodes) {
+                    auto nid_len = graph.__node_length(node);
+                    if (!nid_len) {
+                        throw std::invalid_argument(
+                            fmt::format("missing node {}", node));
+                    }
+                    nids.push_back(std::get<0>(*nid_len));
+                    lengths.push_back(std::get<1>(*nid_len));
+                }
+                double dist = 0.0;
+                for (size_t i = 1; i < N - 1; ++i) {
+                    dist += lengths[i];
+                }
+                if (start_offset) {
+                    start_offset = CLIP(0.0, *start_offset, lengths.front());
+                    dist += lengths.front() - *start_offset;
+                }
+                if (end_offset) {
+                    end_offset = CLIP(0.0, *end_offset, lengths.back());
+                    dist += *end_offset;
+                }
+                auto p = Path(&graph, dist, nids, start_offset, end_offset);
+                auto round_scale = graph.round_scale();
+                if (round_scale) {
+                    p.round(*round_scale);
+                }
+                if (binding) {
+                    auto node = std::get<0>(*binding);
+                    auto nid = graph.__node_id(node);
+                    if (!nid) {
+                        throw std::invalid_argument(
+                            fmt::format("invalid binding node {}", node));
+                    }
+                    p.binding = std::make_tuple(*nid, std::get<1>(*binding));
+                }
+                return p;
+            },
+            "graph"_a, "nodes"_a,            //
+            py::kw_only(),                   //
+            "start_offset"_a = std::nullopt, //
+            "end_offset"_a = std::nullopt,   //
+            "binding"_a = std::nullopt)
+
         .def_property_readonly(
             "graph", [](const Path &self) { return self.graph; },
             rvp::reference_internal)
@@ -1982,7 +2053,11 @@ PYBIND11_MODULE(_core, m)
             })
         .def_property_readonly(
             "binding",
-            [](const Path &self) {
+            [](const Path &self)
+                -> std::optional<std::tuple<std::string, Binding>> {
+                if (!self.binding) {
+                    return {};
+                }
                 return std::make_tuple( //
                     self.graph->__node_id(std::get<0>(*self.binding)),
                     std::get<1>(*self.binding));

tests/test_basic.py

@@ -16,7 +16,7 @@
 
 
 def test_version():
-    assert m.__version__ == "0.1.6"
+    assert m.__version__ == "0.1.7"
 
 
 def test_add():
@@ -1352,3 +1352,39 @@ def test_ubodt():
     assert len(G2.nodes) == 0
     spath = ShortestPathWithUbodt(G2, rows)
     assert spath.path("w1", "w4").nodes == ["w1", "w3", "w4"]
+
+    path = spath.path("w1", "w4")
+    path2 = Path.Build(G, path.nodes)
+    assert path.to_dict() == path2.to_dict()
+
+    path2 = Path.Build(G, path.nodes, start_offset=5.0, end_offset=17.0)
+    assert path2.dist == 32.0
+    assert path2.nodes == path.nodes
+    assert path2.start == ("w1", 5.0)
+    assert path2.end == ("w4", 17.0)
+    path2 = Path.Build(G, path.nodes, start_offset=5.12345, end_offset=27.0)
+    assert path2.dist == 34.877
+    assert path2.start[1] == 5.123
+    assert path2.end[1] == 20.0
+
+    path2 = Path.Build(
+        G,
+        path.nodes,
+        start_offset=5.12345,
+        end_offset=27.0,
+        binding=("w3", (5.0, 5.0, "something")),
+    )
+    assert path2.binding == ("w3", (5.0, 5.0, "something"))
+
+    with pytest.raises(ValueError) as e:  # noqa: PT011
+        path2 = Path.Build(G, ["w1", "w3", "no_such_road"])
+    assert "missing node no_such_road" in repr(e)
+    with pytest.raises(ValueError) as e:  # noqa: PT011
+        path2 = Path.Build(
+            G,
+            path.nodes,
+            start_offset=5.12345,
+            end_offset=27.0,
+            binding=("no_such_road", (5.0, 5.0, "something")),
+        )
+    assert "invalid binding node no_such_road" in repr(e)