Reflection Queries #2
Description
Now that file parsing and reflection are complete it's time to improve ergonomics. After some discussions with friends, I think a query api will be a nice starting point.
Queries
Types and blocks should expose a set of Query functions. These functions will accept a std::string_view containing a query. Queries will be transformed (preferably at compile time) into a set of operations on the given BlendType "hierarchy".
BlendType::QueryValue(std::span, std::string_view query)
This template would allow you query a value of T from the given span. Would primarily be used internally.
using Vec3f = Vec2<float>;
auto mesh = blend.GetBlock(BLOCK_CODE_ME);
auto mesh_type = blend.GetBlockType(*mesh);
auto totlayer = mesh_type->QueryValue<Vec3f>(mesh.header.data, "size"); // size is an array of the fundamental type floatBlendType::QueryValue(const Block& block, std::string_view query)
This template would allow you query a value of T from the block Block. Would primarily be used internally.
auto mesh = blend.GetBlock(BLOCK_CODE_ME);
auto mesh_type = blend.GetBlockType(*mesh);
auto totlayer = mesh_type->QueryValue<int>(mesh, "vdata.totlayer"); // vdata is an aggregate field, and totlayer is a fundamental fieldBlendBlock::QueryValue(std::string_view query)
This template would allow you query a value of T from the given Block.
auto mesh = blend.GetBlock(BLOCK_CODE_ME);
auto totlayer = mesh->QueryValue<int>("totvert"); // totvert is a fundamental fieldQuery Language
The query language should be as simple as possible while still being robust.
Aggregates
Aggregate fields can be indexed directly by name.
mesh->QueryValue<SymmetryMode>("symmetry");Arrays
Arrays can be returned by value.
mesh->QueryValue<Vec3f>("size");
mesh->QueryValue<float[3]>("size");
mesh->QueryValue<std::array<float, 8>>("size");Arrays values can be directly addressed.
mesh->QueryValue<float>("loc[0]");
mesh->QueryValue<float>("loc[1]");
mesh->QueryValue<float>("loc[2]");Pointers
Pointers are treated as if they are references with safety.
mesh->QueryValue("vdata.data");Pointers can be indexed as arrays without safety.
mesh->QueryValue<Vertex>("vdata.data[0]");Pointers can be read as arrays without safety.
mesh->QueryValue<Vertex[8]>("vdata.data[0]");