Journal of Computational Physics 1997, 138, 981-990

Paper (PostScript).

The LASY Preprocessor and its Application to

General Multi-Dimensional Codes

Gábor Tóth

Sterrenkundig Instituut, Utrecht, The Netherlands


A new preprocessor using the Loop Annotation Syntax is described. One of the possible applications of this syntax is writing a general simulation code where the number of grid dimensions is a parameter of the preprocessor. Programming language constructs, which would be normally repeated for each dimensions separately, are annotated as loops in the syntax, and these loops can be expanded by the preprocessor. The preprocessor overcomes some of the inherent limitations of most computer languages, such as the fixed number of indices for arrays. In general the typical expressions used in multi-dimensional simulation codes can be written in a way that is more concise and less prone to error. The preprocessor is implemented in the Perl language which is available for almost all operating systems.