3.10 Demonstration programs

The demos subdirectory has some sample programs using GMP. These aren’t built or installed, but there’s a Makefile with rules for them. For instance,

make pexpr
./pexpr 68^975+10

The following programs are provided

• ‘pexpr’ is an expression evaluator, the program used on the GMP web page.
• The ‘calc’ subdirectory has a similar but simpler evaluator using lex and yacc.
• The ‘expr’ subdirectory is yet another expression evaluator, a library designed for ease of use within a C program. See demos/expr/README for more information.
• ‘factorize’ is a Pollard-Rho factorization program.
• ‘isprime’ is a command-line interface to the mpz_probab_prime_p function.
• ‘primes’ counts or lists primes in an interval, using a sieve.
• ‘qcn’ is an example use of mpz_kronecker_ui to estimate quadratic class numbers.
• The ‘perl’ subdirectory is a comprehensive perl interface to GMP. See demos/perl/INSTALL for more information. Documentation is in POD format in demos/perl/GMP.pm.

As an aside, consideration has been given at various times to some sort of expression evaluation within the main GMP library. Going beyond something minimal quickly leads to matters like user-defined functions, looping, fixnums for control variables, etc, which are considered outside the scope of GMP (much closer to language interpreters or compilers, See Language Bindings.) Something simple for program input convenience may yet be a possibility, a combination of the expr demo and the pexpr tree back-end perhaps. But for now the above evaluators are offered as illustrations.