NOTE: Development of these functions has been moved to souffle-lib.
Souffle is a capable Datalog implementation which allows for easy integration with C functions. This package defines a set of functors for using some of the C math functions in Souffle (assuming double precision, with ./configure --enable-64bit-domain).
As a simple example, we have the following Souffle test.dl file:
#include "math.dl"
.decl Summary(label: symbol, y: float)
Summary("@exp(1.0)", @exp(1.0)) :- true.
Summary("@log(@exp(1.0))", @log(@exp(1.0))) :- true.
.output Summary
This reads in the functor definitions, declares a Summary relationship, and calculates two values. The code to run this in the interpreter may be as simple as souffle -lm test.dl or in the compiler using souffle -c -lm test.dl. When libm is an ld script, this code will not work for the Souffle interpreter. We provide a bash script lib_ldscript for transforming the library arguments when there is an ld script. As an example:
souffle `lib_ldscript -lm` test.dl
cat Summary.csv| @exp(1.0) | 2.718281828459045 |
| @log(@exp(1.0)) | 1 |
Documentation is available in the math.dl file.