Merge pull request #1484 from ExtremeFLOW/doc/types

doc/Makefile.am

@@ -20,6 +20,7 @@ EXTRA_DIST = pages/appendices/governing-equations.md \
 			pages/developer-guide \
 			pages/developer-guide/accelerators.md \
 			pages/developer-guide/run_time_selectable_types.md \
+			pages/developer-guide/important_types.md \
 			pages/developer-guide/code-style.md \
 			pages/developer-guide/contributing.md \
 			pages/developer-guide/dev_patterns.md \

doc/pages/developer-guide.md

@@ -10,3 +10,4 @@ style, testing and usage of accelerators.
 - \subpage testing
 - \subpage accelerators
 - \subpage rts_types
+- \subpage important_types

doc/pages/developer-guide/important_types.md

@@ -0,0 +1,70 @@
+# Important types {#important_types}
+
+\tableofcontents
+
+This section is meant to help new developers get a quick introduction to some of
+the most important types in Neko, to get an idea of where to look for what. In
+this spirit, the descriptions here are not meant to be exhaustive. In many
+cases, we will just point to top type in a hierarchy, and leave the reader to
+explore the descendants.
+
+
+## SEM foundation types
+
+- [mesh_t](#mesh::mesh_t): The computational mesh.
+- [space_t](#space::space_t): The function space in which the solution is
+  sought. Contains things related to the polynomial basis within each element.
+- [dofmap_t](#dofmap::dofmap_t): Map of degrees of freedom. Most importantly, it
+  holds all the GLL nodes locations.
+- [coef_t](#coefs::coef_t): Stores coefficients for transformation to and from
+  the reference element, along with some other auxillary data. 
+- [gs_t](#gather_scatter::gs_t): Gather-scatter kernels used to make the
+  solution continuous, i.e. perform direct stiffness summation. 
+- [field_t](#field::field_t): The main type for storing the unknowns, and
+  essentially everything else that lives on the mesh. 
+
+## Basic math routines
+Here, we also list file names rather than types, since the basic math is implemented
+as subroutines.
+
+- `math.f90`: Basic math operations on raw arrays.
+- `device_math.f90`: Basic math operations on device arrays.
+- `field_math.f90`: Basic math operations on [field_t](#field::field_t).
+- `operators.f90`: Various explicit operators, including derivatives, etc.
+- [vector_t](#vector::vector_t) and [matrix_t](#matrix::matrix_t): 1D and 2D arrays
+  with support for computation on [accelerators](#accelerators).
+
+## Governing equation solvers and related types
+
+- [case_t](#case::case_t): An abstraction for the simulation case. Stores the
+  fluid and scalar solver as components, handles IO via
+  [sampler_t](#sampler::sampler_t).
+- [fluid_scheme_t](#fluid_scheme::fluid_scheme_t): Navier-Stokes solvers.
+- [scalar_scheme_t](#scalar_scheme::scalar_scheme_t): Scalar
+  advection-diffusion-reaction solvers.
+- [bc_t](#bc::bc_t): Boundary conditions.
+- [time_scheme_t](#time_scheme::time_scheme_t): Time integration schemes.
+- [source_term_t](#source_term::source_term_t): Source terms.
+
+## Singletons
+
+Singleton types are meant to only have a single object of their kind to be
+created. These objects are declared in the same module where the type resides,
+and all have their name starting with `neko_`.
+
+- [field_registry_t](#field_registry::field_registry_t): A registry of
+  [field_t](#field::field_t), retrievable by name or index. This is the main
+  object used to access the fields of unknowns for any place in the code.
+- [scratch_registry_t](#scratch_registry::scratch_registry_t): Provides a
+  mechanism to get a temporary [field_t](#field::field_t) for doing some work.
+  Use this instead of creating temporary fields inside a subroutine. 
+- [simcomp_executor_t](#simcomp_executor::simcomp_executor_t): Driver for
+  simulation components. The object is called `neko_simcomps`.
+- [log_t](#logger::log_t): Used to write to the simulation log.
+
+## Linear algebra
+
+- [ksp_t](#krylov::ksp_t): Krylov solvers.
+- [pc_t](#precon::pc_t): Preconditioners.
+
+