Refactor de_export.py, extract _codegen.model_class (#2319)

Move functionality for generating the ``amici::Model`` subclass code to a separate file.

Related to #2306

python/sdist/amici/_codegen/model_class.py

@@ -0,0 +1,191 @@
+"""Function for generating the ``amici::Model`` subclass for an amici model."""
+from __future__ import annotations
+
+from .cxx_functions import functions, multiobs_functions
+
+from ..de_model_components import Event
+
+
+def get_function_extern_declaration(fun: str, name: str, ode: bool) -> str:
+    """
+    Constructs the extern function declaration for a given function
+
+    :param fun:
+        function name
+    :param name:
+        model name
+    :param ode:
+        whether to generate declaration for DAE or ODE
+
+    :return:
+        C++ function definition string
+    """
+    f = functions[fun]
+    return f"extern {f.return_type} {fun}_{name}({f.arguments(ode)});"
+
+
+def get_sunindex_extern_declaration(
+    fun: str, name: str, indextype: str
+) -> str:
+    """
+    Constructs the function declaration for an index function of a given
+    function
+
+    :param fun:
+        function name
+
+    :param name:
+        model name
+
+    :param indextype:
+        index function {'colptrs', 'rowvals'}
+
+    :return:
+        C++ function declaration string
+    """
+    index_arg = ", int index" if fun in multiobs_functions else ""
+    return (
+        f"extern void {fun}_{indextype}_{name}"
+        f"(SUNMatrixWrapper &{indextype}{index_arg});"
+    )
+
+
+def get_model_override_implementation(
+    fun: str, name: str, ode: bool, nobody: bool = False
+) -> str:
+    """
+    Constructs ``amici::Model::*`` override implementation for a given function
+
+    :param fun:
+        function name
+
+    :param name:
+        model name
+
+    :param nobody:
+        whether the function has a nontrivial implementation
+
+    :return:
+        C++ function implementation string
+    """
+    func_info = functions[fun]
+    body = (
+        ""
+        if nobody
+        else "\n{ind8}{maybe_return}{fun}_{name}({eval_signature});\n{ind4}".format(
+            ind4=" " * 4,
+            ind8=" " * 8,
+            maybe_return="" if func_info.return_type == "void" else "return ",
+            fun=fun,
+            name=name,
+            eval_signature=remove_argument_types(func_info.arguments(ode)),
+        )
+    )
+    return "{return_type} f{fun}({signature}) override {{{body}}}\n".format(
+        return_type=func_info.return_type,
+        fun=fun,
+        signature=func_info.arguments(ode),
+        body=body,
+    )
+
+
+def get_sunindex_override_implementation(
+    fun: str, name: str, indextype: str, nobody: bool = False
+) -> str:
+    """
+    Constructs the ``amici::Model`` function implementation for an index
+    function of a given function
+
+    :param fun:
+        function name
+
+    :param name:
+        model name
+
+    :param indextype:
+        index function {'colptrs', 'rowvals'}
+
+    :param nobody:
+        whether the corresponding function has a nontrivial implementation
+
+    :return:
+        C++ function implementation string
+    """
+    index_arg = ", int index" if fun in multiobs_functions else ""
+    index_arg_eval = ", index" if fun in multiobs_functions else ""
+
+    impl = "void f{fun}_{indextype}({signature}) override {{"
+
+    if nobody:
+        impl += "}}\n"
+    else:
+        impl += (
+            "\n{ind8}{fun}_{indextype}_{name}({eval_signature});\n{ind4}}}\n"
+        )
+
+    return impl.format(
+        ind4=" " * 4,
+        ind8=" " * 8,
+        fun=fun,
+        indextype=indextype,
+        name=name,
+        signature=f"SUNMatrixWrapper &{indextype}{index_arg}",
+        eval_signature=f"{indextype}{index_arg_eval}",
+    )
+
+
+def remove_argument_types(signature: str) -> str:
+    """
+    Strips argument types from a function signature
+
+    :param signature:
+        function signature
+
+    :return:
+        string that can be used to construct function calls with the same
+        variable names and ordering as in the function signature
+    """
+    # remove * prefix for pointers (pointer must always be removed before
+    # values otherwise we will inadvertently dereference values,
+    # same applies for const specifications)
+    #
+    # always add whitespace after type definition for cosmetic reasons
+    known_types = [
+        "const realtype *",
+        "const double *",
+        "const realtype ",
+        "double *",
+        "realtype *",
+        "const int ",
+        "int ",
+        "bool ",
+        "SUNMatrixContent_Sparse ",
+        "gsl::span<const int>",
+    ]
+
+    for type_str in known_types:
+        signature = signature.replace(type_str, "")
+
+    return signature
+
+
+def get_state_independent_event_intializer(events: list[Event]) -> str:
+    """Get initializer list for state independent events in amici::Model."""
+    map_time_to_event_idx = {}
+    for event_idx, event in enumerate(events):
+        if not event.triggers_at_fixed_timepoint():
+            continue
+        trigger_time = float(event.get_trigger_time())
+        try:
+            map_time_to_event_idx[trigger_time].append(event_idx)
+        except KeyError:
+            map_time_to_event_idx[trigger_time] = [event_idx]
+
+    def vector_initializer(v):
+        """std::vector initializer list with elements from `v`"""
+        return f"{{{', '.join(map(str, v))}}}"
+
+    return ", ".join(
+        f"{{{trigger_time}, {vector_initializer(event_idxs)}}}"
+        for trigger_time, event_idxs in map_time_to_event_idx.items()
+    )