+# define EMBRYO_CELL_TO_FLOAT(c) (((Embryo_Float_Cell *)&(c))->f)
+#else
+/** Float to Embryo_Cell */
+# define EMBRYO_FLOAT_TO_CELL(f) ((Embryo_Float_Cell) f).c
+/** Embryo_Cell to float */
+# define EMBRYO_CELL_TO_FLOAT(c) ((Embryo_Float_Cell) c).f
+#endif
+
+ /**
+ * @defgroup Embryo_Library_Group Library Maintenance Functions
+ *
+ * Functions that start up and shutdown the Embryo library.
+ */
+
+
+/**
+ * Initialises the Embryo library.
+ * @return The number of times the library has been initialised without being
+ * shut down.
+ * @ingroup Embryo_Library_Group
+ */
+EAPI int embryo_init(void);
+
+/**
+ * Shuts down the Embryo library.
+ * @return The number of times the library has been initialised without being
+ * shutdown.
+ * @ingroup Embryo_Library_Group
+ */
+EAPI int embryo_shutdown(void);
+
+ /**
+ * @defgroup Embryo_Program_Creation_Group Program Creation and Destruction Functions
+ *
+ * Functions that set up programs, and destroy them.
+ */
+
+/**
+ * Creates a new Embryo program, with bytecode data that can be freed.
+ * @param data Pointer to the bytecode of the program.
+ * @param size Number of bytes of bytecode.
+ * @return A new Embryo program.
+ * @ingroup Embryo_Program_Creation_Group
+ */
+EAPI Embryo_Program *embryo_program_new(void *data, int size);
+
+/**
+ * Creates a new Embryo program, with bytecode data that cannot be
+ * freed.
+ * @param data Pointer to the bytecode of the program.
+ * @param size Number of bytes of bytecode.
+ * @return A new Embryo program.
+ * @ingroup Embryo_Program_Creation_Group
+ */
+EAPI Embryo_Program *embryo_program_const_new(void *data, int size);
+
+/**
+ * Creates a new Embryo program based on the bytecode data stored in the
+ * given file.
+ * @param file Filename of the given file.
+ * @return A new Embryo program.
+ * @ingroup Embryo_Program_Creation_Group
+ */
+EAPI Embryo_Program *embryo_program_load(const char *file);
+
+/**
+ * Frees the given Embryo program.
+ * @param ep The given program.
+ * @ingroup Embryo_Program_Creation_Group
+ */
+EAPI void embryo_program_free(Embryo_Program *ep);
+
+/**
+ * Adds a native program call to the given Embryo program.
+ * @param ep The given Embryo program.
+ * @param name The name for the call used in the script.
+ * @param func The function to use when the call is made.
+ * @ingroup Embryo_Func_Group
+ */
+
+/**
+ * @defgroup Embryo_Func_Group Function Functions
+ *
+ * Functions that deal with Embryo program functions.
+ */
+EAPI void embryo_program_native_call_add(Embryo_Program *ep, const char *name, Embryo_Cell (*func) (Embryo_Program *ep, Embryo_Cell *params));
+
+/**
+ * Resets the current virtual machine session of the given program.
+ * @param ep The given program.
+ * @ingroup Embryo_Program_VM_Group
+ */
+
+/**
+ * @defgroup Embryo_Program_VM_Group Virtual Machine Functions
+ *
+ * Functions that deal with creating and destroying virtual machine sessions
+ * for a given program.
+ *
+ * A given embryo program can have multiple virtual machine sessions running.
+ * This is useful when you have a native call that in turn calls a function in
+ * the embryo program. The native call can start a new virtual machine
+ * session to run the function it needs. Once completed, the session can be
+ * popped off the program's stack, and the native call can return its value
+ * to the old session.
+ *
+ * A new virtual machine session is created by pushing a new virtual machine
+ * onto the session stack of a program using @ref embryo_program_vm_push.
+ * The current virtual machine session can be destroyed by calling
+ * @ref embryo_program_vm_pop.
+ */
+EAPI void embryo_program_vm_reset(Embryo_Program *ep);
+
+/**
+ * Starts a new virtual machine session for the given program.
+ *
+ * See @ref Embryo_Program_VM_Group for more information about how this works.
+ *
+ * @param ep The given program.
+ * @ingroup Embryo_Program_VM_Group
+ */
+EAPI void embryo_program_vm_push(Embryo_Program *ep);
+
+/**
+ * Frees the current virtual machine session associated with the given program.
+ *
+ * See @ref Embryo_Program_VM_Group for more information about how this works.
+ * Note that you will need to retrieve any return data or data on the stack
+ * before you pop.
+ *
+ * @param ep The given program.
+ * @ingroup Embryo_Program_VM_Group
+ */
+EAPI void embryo_program_vm_pop(Embryo_Program *ep);
+
+/**
+ * Ensures that the given unsigned short integer is in the small
+ * endian format.
+ * @param v Pointer to the given integer.
+ * @ingroup Embryo_Swap_Group
+ */
+
+/**
+ * @defgroup Embryo_Swap_Group Byte Swapping Functions
+ *
+ * Functions that are used to ensure that integers passed to the
+ * virtual machine are in small endian format. These functions are
+ * used to ensure that the virtual machine operates correctly on big
+ * endian machines.
+ */
+EAPI void embryo_swap_16(unsigned short *v);
+
+/**
+ * Ensures that the given unsigned integer is in the small endian
+ * format.
+ * @param v Pointer to the given integer.
+ * @ingroup Embryo_Swap_Group
+ */
+EAPI void embryo_swap_32(unsigned int *v);
+
+/**
+ * Returns the function in the given program with the given name.
+ * @param ep The given program.
+ * @param name The given function name.
+ * @return The function if successful. Otherwise, @c EMBRYO_FUNCTION_NONE.
+ * @ingroup Embryo_Func_Group
+ */
+EAPI Embryo_Function embryo_program_function_find(Embryo_Program *ep, const char *name);
+
+/**
+ * Retrieves the location of the public variable in the given program
+ * with the given name.
+ * @param ep The given program.
+ * @param name The given name.
+ * @return The address of the variable if found. @c EMBRYO_CELL_NONE
+ * otherwise.
+ * @ingroup Embryo_Public_Variable_Group
+ */
+
+/**
+ * @defgroup Embryo_Public_Variable_Group Public Variable Access Functions
+ *
+ * In an Embryo program, a global variable can be declared public, as
+ * described in @ref Small_Scope_Subsection. The functions here allow
+ * the host program to access these public variables.
+ */
+EAPI Embryo_Cell embryo_program_variable_find(Embryo_Program *ep, const char *name);
+
+/**
+ * Retrieves the number of public variables in the given program.
+ * @param ep The given program.
+ * @return The number of public variables.
+ * @ingroup Embryo_Public_Variable_Group
+ */
+EAPI int embryo_program_variable_count_get(Embryo_Program *ep);
+
+/**
+ * Retrieves the location of the public variable in the given program
+ * with the given identifier.
+ * @param ep The given program.
+ * @param num The identifier of the public variable.
+ * @return The virtual machine address of the variable if found.
+ * @c EMBRYO_CELL_NONE otherwise.
+ * @ingroup Embryo_Public_Variable_Group
+ */
+EAPI Embryo_Cell embryo_program_variable_get(Embryo_Program *ep, int num);
+
+/**
+ * Sets the error code for the given program to the given code.
+ * @param ep The given program.
+ * @param error The given error code.
+ * @ingroup Embryo_Error_Group
+ */
+
+/**
+ * @defgroup Embryo_Error_Group Error Functions
+ *
+ * Functions that set and retrieve error codes in Embryo programs.
+ */
+EAPI void embryo_program_error_set(Embryo_Program *ep, Embryo_Error error);
+
+/**
+ * Retrieves the current error code for the given program.
+ * @param ep The given program.
+ * @return The current error code.
+ * @ingroup Embryo_Error_Group
+ */
+EAPI Embryo_Error embryo_program_error_get(Embryo_Program *ep);
+
+/**
+ * Sets the data associated to the given program.
+ * @param ep The given program.
+ * @param data New bytecode data.
+ * @ingroup Embryo_Program_Data_Group
+ */
+
+/**
+ * @defgroup Embryo_Program_Data_Group Program Data Functions
+ *
+ * Functions that set and retrieve data associated with the given
+ * program.
+ */
+EAPI void embryo_program_data_set(Embryo_Program *ep, void *data);
+
+/**
+ * Retrieves the data associated to the given program.
+ * @param ep The given program.
+ * @ingroup Embryo_Program_Data_Group
+ */
+EAPI void *embryo_program_data_get(Embryo_Program *ep);
+
+/**
+ * Retrieves a string describing the given error code.
+ * @param error The given error code.
+ * @return String describing the given error code. If the given code is not
+ * known, the string "(unknown)" is returned.
+ * @ingroup Embryo_Error_Group
+ */
+EAPI const char *embryo_error_string_get(Embryo_Error error);
+
+/**
+ * Retrieves the length of the string starting at the given cell.
+ * @param ep The program the cell is part of.
+ * @param str_cell Pointer to the first cell of the string.
+ * @return The length of the string. @c 0 is returned if there is an error.
+ * @ingroup Embryo_Data_String_Group
+ */
+
+/**
+ * @defgroup Embryo_Data_String_Group Embryo Data String Functions
+ *
+ * Functions that operate on strings in the memory of a virtual machine.
+ */
+EAPI int embryo_data_string_length_get(Embryo_Program *ep, Embryo_Cell *str_cell);
+
+/**
+ * Copies the string starting at the given cell to the given buffer.
+ * @param ep The program the cell is part of.
+ * @param str_cell Pointer to the first cell of the string.
+ * @param dst The given buffer.
+ * @ingroup Embryo_Data_String_Group
+ */
+EAPI void embryo_data_string_get(Embryo_Program *ep, Embryo_Cell *str_cell, char *dst);
+
+/**
+ * Copies string in the given buffer into the virtual machine memory
+ * starting at the given cell.
+ * @param ep The program the cell is part of.
+ * @param src The given buffer.
+ * @param str_cell Pointer to the first cell to copy the string to.
+ * @ingroup Embryo_Data_String_Group
+ */
+EAPI void embryo_data_string_set(Embryo_Program *ep, const char *src, Embryo_Cell *str_cell);
+
+/**
+ * Retreives a pointer to the address in the virtual machine given by the
+ * given cell.
+ * @param ep The program whose virtual machine address is being queried.
+ * @param addr The given cell.
+ * @return A pointer to the cell at the given address.
+ * @ingroup Embryo_Data_String_Group
+ */
+EAPI Embryo_Cell *embryo_data_address_get(Embryo_Program *ep, Embryo_Cell addr);
+
+/**
+ * Increases the size of the heap of the given virtual machine by the given
+ * number of Embryo_Cells.
+ * @param ep The program with the given virtual machine.
+ * @param cells The given number of Embryo_Cells.
+ * @return The address of the new memory region on success.
+ * @c EMBRYO_CELL_NONE otherwise.
+ * @ingroup Embryo_Heap_Group
+ */
+
+/**
+ * @defgroup Embryo_Heap_Group Heap Functions
+ *
+ * The heap is an area of memory that can be allocated for program
+ * use at runtime. The heap functions here change the amount of heap
+ * memory available.
+ */
+EAPI Embryo_Cell embryo_data_heap_push(Embryo_Program *ep, int cells);
+
+/**
+ * Decreases the size of the heap of the given virtual machine down to the
+ * given size.
+ * @param ep The program with the given virtual machine.
+ * @param down_to The given size.
+ * @ingroup Embryo_Heap_Group
+ */
+EAPI void embryo_data_heap_pop(Embryo_Program *ep, Embryo_Cell down_to);
+
+/**
+ * Returns the number of virtual machines are running for the given program.
+ * @param ep The given program.
+ * @return The number of virtual machines running.
+ * @ingroup Embryo_Run_Group
+ */
+
+/**
+ * @defgroup Embryo_Run_Group Program Run Functions
+ *
+ * Functions that are involved in actually running functions in an
+ * Embryo program.
+ */
+EAPI int embryo_program_recursion_get(Embryo_Program *ep);
+
+/**
+ * Runs the given function of the given Embryo program in the current
+ * virtual machine. The parameter @p fn can be found using
+ * @ref embryo_program_function_find.
+ *
+ * @note For Embryo to be able to run a function, it must have been
+ * declared @c public in the Small source code.
+ *
+ * @param ep The given program.
+ * @param func The given function. Normally "main", in which case the
+ * constant @c EMBRYO_FUNCTION_MAIN can be used.
+ * @return @c EMBRYO_PROGRAM_OK on success. @c EMBRYO_PROGRAM_SLEEP if the
+ * program is halted by the Small @c sleep call.
+ * @c EMBRYO_PROGRAM_FAIL if there is an error.
+ * @c EMBRYO_PROGRAM_TOOLONG if the program executes for longer than
+ * it is allowed to in abstract machine instruction count.
+ * @ingroup Embryo_Run_Group
+ */
+EAPI Embryo_Status embryo_program_run(Embryo_Program *ep, Embryo_Function func);
+
+/**
+ * Retreives the return value of the last called function of the given
+ * program.
+ * @param ep The given program.
+ * @return An Embryo_Cell representing the return value of the function
+ * that was last called.
+ * @ingroup Embryo_Run_Group
+ */
+EAPI Embryo_Cell embryo_program_return_value_get(Embryo_Program *ep);
+
+/**
+ * Sets the maximum number of abstract machine cycles any given program run
+ * can execute before being put to sleep and returning.
+ *
+ * @param ep The given program.
+ * @param max The number of machine cycles as a limit.
+ *
+ * This sets the maximum number of abstract machine (virtual machine)
+ * instructions that a single run of an embryo function (even if its main)
+ * can use before embryo embryo_program_run() reutrns with the value
+ * EMBRYO_PROGRAM_TOOLONG. If the function fully executes within this number
+ * of cycles, embryo_program_run() will return as normal with either
+ * EMBRYO_PROGRAM_OK, EMBRYO_PROGRAM_FAIL or EMBRYO_PROGRAM_SLEEP. If the
+ * run exceeds this instruction count, then EMBRYO_PROGRAM_TOOLONG will be
+ * returned indicating the program exceeded its run count. If the app wishes
+ * to continue running this anyway - it is free to process its own events or
+ * whatever it wants and continue the function by calling
+ * embryo_program_run(program, EMBRYO_FUNCTION_CONT); which will start the
+ * run again until the instruction count is reached. This can keep being done
+ * to allow the calling program to still be able to control things outside the
+ * embryo function being called. If the maximum run cycle count is 0 then the
+ * program is allowed to run forever only returning when it is done.
+ *
+ * It is important to note that abstract machine cycles are NOT the same as
+ * the host machine cpu cycles. They are not fixed in runtime per cycle, so
+ * this is more of a helper tool than a way to HARD-FORCE a script to only
+ * run for a specific period of time. If the cycle count is set to something
+ * low like 5000 or 1000, then every 1000 (or 5000) cycles control will be
+ * returned to the calling process where it can check a timer to see if a
+ * physical runtime limit has been elapsed and then abort running further
+ * assuming a "runaway script" or keep continuing the script run. This
+ * limits resolution to only that many cycles which do not take a determined
+ * amount of time to execute, as this varies from cpu to cpu and also depends
+ * on how loaded the system is. Making the max cycle run too low will
+ * impact performance requiring the abstract machine to do setup and teardown
+ * cycles too often comapred to cycles actually executed.
+ *
+ * Also note it does NOT include nested abstract machines. IF this abstract
+ * machine run calls embryo script that calls a native function that in turn
+ * calls more embryo script, then the 2nd (and so on) levels are not included
+ * in this run count. They can set their own max instruction count values
+ * separately.
+ *
+ * The default max cycle run value is 0 in any program until set with this
+ * function.
+ *
+ * @ingroup Embryo_Run_Group
+ */
+EAPI void embryo_program_max_cycle_run_set(Embryo_Program *ep, int max);
+
+/**
+ * Retreives the maximum number of abstract machine cycles a program is allowed
+ * to run.
+ * @param ep The given program.
+ * @return The number of cycles a run cycle is allowed to run for this
+ * program.
+ *
+ * This returns the value set by embryo_program_max_cycle_run_set(). See
+ * embryo_program_max_cycle_run_set() for more information.
+ *
+ * @ingroup Embryo_Run_Group
+ */
+EAPI int embryo_program_max_cycle_run_get(Embryo_Program *ep);
+
+/**
+ * Pushes an Embryo_Cell onto the function stack to use as a parameter for
+ * the next function that is called in the given program.
+ * @param ep The given program.
+ * @param cell The Embryo_Cell to push onto the stack.
+ * @return @c 1 if successful. @c 0 otherwise.
+ * @ingroup Embryo_Parameter_Group
+ */
+
+/**
+ * @defgroup Embryo_Parameter_Group Function Parameter Functions
+ *
+ * Functions that set parameters for the next function that is called.
+ */
+EAPI int embryo_parameter_cell_push(Embryo_Program *ep, Embryo_Cell cell);
+
+/**
+ * Pushes a string onto the function stack to use as a parameter for the
+ * next function that is called in the given program.
+ * @param ep The given program.
+ * @param str The string to push onto the stack.
+ * @return @c 1 if successful. @c 0 otherwise.
+ * @ingroup Embryo_Parameter_Group
+ */
+EAPI int embryo_parameter_string_push(Embryo_Program *ep, const char *str);
+
+/**
+ * Pushes an array of Embryo_Cells onto the function stack to be used as
+ * parameters for the next function that is called in the given program.
+ * @param ep The given program.
+ * @param cells The array of Embryo_Cells.
+ * @param num The number of cells in @p cells.
+ * @return @c 1 if successful. @c 0 otherwise.
+ * @ingroup Embryo_Parameter_Group
+ */
+EAPI int embryo_parameter_cell_array_push(Embryo_Program *ep, Embryo_Cell *cells, int num);