gen_constant: Basic property-based test generators

In s7contract: Behavioral Contracts and Generative Laws for 'S7'

Basic property-based test generators

Description

These generators carry their own deterministic shrink trees. Integer ranges and vector lengths expand with the runner's size. Integer values shrink toward zero when zero is within bounds, or toward the nearest bound. Product generators shrink one component at a time in argument order. Vector generators return an atomic vector only when the element prototype is atomic; those element draws must be scalar and match the prototype's storage type. Otherwise, vector generators return a list with one entry per element draw. Nested vector generators therefore return lists of vectors. Vector shrinking removes contiguous chunks, then shrinks individual elements, preserving the minimum length.

Usage

gen_constant(value)

gen_integer(min = -100L, max = 100L)

gen_map(generator, transform, prototype = list())

gen_product(...)

gen_vector(element, min = 0L, max = 10L)

Arguments

value	Constant value to generate.
min, max	Inclusive integer bounds. For gen_vector(), bounds on vector length.
generator, element	A generator.
transform	Function applied to generated values.
prototype	Zero-length prototype of mapped values.
...	Uniquely named generators.

Value

An S7 generator object.

Examples

pairs <- gen_product(x = gen_integer(), y = gen_integer())
vectors <- gen_vector(gen_integer(), min = 0L, max = 8L)

s7contract documentation built on Sept. 10, 2026, 1:09 a.m.