Naming Conventions


Unit names have their first letter capitalized, for example Grid, Eos, Hydro etc


Subunits have composite names that include a full unit name followed by a capitalized word describing the subunit, for example GridMain, GridParticles, HydroMain etc. Every unit has at least one subunit named UnitMain.

Subunits Implementations

The directories containing implementations of sub units have the following convention: If there are no implementations of the unit API in any of its child directories, then the current directory name is capilaized, otherwise it is all smallcase.

Organizational directories

These directory are normal unix directories, used for organizational purposes. For example <physics> is an organizational directory for all the physics units. All helper and utilities directories are lowercase too.

Unit API functions

Unit_routineName is the typical format of API function names. The unit name is followed by an underscore. The first word in the remaining part of the name is lowercase and all subsequent words are capitalized. For example, Grid_fillGuardcells, Driver_getDt} etc

Private UnitMain funtions

The private functions are named un_routineName, where un stands for a short string (usually 2 or 3 letters) derived from the unit name. For example gr_createDomain is a private function in the GridMain subunit.

Private Subunit functions

For every subunit other than UnitMain, functions are named un_suRoutineName, where un has the same meaning as for UnitMain, and su is another short string derived from the subunit name. For example gr_ptMoveData is a private function of GridParticles subunit.

Third party functions

Functions imported from elsewhere are not required to, but encouraged to follow the Private unit function convention, as long as they are private to the unit.

Unit Data modules

The main data modules are named Unit_main. For additional data modules, the naming convention is similar to private functions, the unit name is replaced by the short string. There are no such data modules in the current release, but an example would be hy_ppmData, if we needed a data module for the PPM kernel in the Hydro unit.


The Constants are mostly defined in the pre-processor format #define CONSTANT_NAME value. They are all uppercase, sometimes multiple words are separated by an underscore. They are avaiable in “name.h” header files


The unit-scope variables, defined in Unit_data, begin with un_, similar to the convention for private function. For example, gr_myPe and gr_procGrid are variables in the Grid unit. Variables local to a function are not constrained to be named in any specific way.


Macros are new in Flash-X and follow the naming convention of private subunit functions if they are private to a subunit. Unit scope macros follow the naming convention of UnitMain subunit. However, some macros are pre-defined for universal use. Those macros effectively become reserved keywords for the code, and may not be reused elsewhere in the code. Universal macros will reside in their own directory in the Simulations unit.