Expand range sampling from the original u32-only helper to all primitive
integer widths. The new gen_range_<int> methods cover 0..n sampling, while
matching gen_range_<int>_in methods accept standard RangeBounds forms such as
exclusive, inclusive, open-ended, and full-width ranges.
Use rejection sampling against the matching primitive reader for each integer
width. That keeps modulo bias out of the public helpers without introducing a
general RNG trait or depending on rand. Full-width ranges fall back directly to
the primitive reader because their span cannot be represented in the same
integer type.
Document the generated APIs with doctested examples and add a ranges example
that demonstrates unsigned, signed, usize, and full-width sampling.
Test Plan:
- cargo test
- cargo clippy
- cargo clippy --benches
- cargo clippy --tests
- cargo +nightly fmt
Refs: IDEAS.md ergonomics backlog
Add OsRandom::fill_bytes so callers can fill a byte slice without importing
std::io::Read. This keeps the common raw-byte use case close to the rest of
the crate's typed convenience API while still forwarding to the same
/dev/urandom handle.
Implement Default for OsRandom as the infallible convenience constructor. The
fallible OsRandom::try_new API remains the right choice when the caller wants
to handle an unavailable operating-system randomness source explicitly.
Document the public constructors and byte-fill helper with working examples,
and add a runnable bytes example for the top-level workflow.
Test Plan:
- cargo test
- cargo clippy
- cargo clippy --benches
- cargo clippy --tests
- cargo +nightly fmt
Refs: IDEAS.md ergonomics backlog
Adds examples/demo.rs so users can quickly see the crate in action via
`cargo run --example demo` without writing any glue code first.
The example exercises the three main surface areas of the crate:
- the typed primitive readers (get_u8, get_u32, get_u64, get_i32) to
show that every integer width is covered and that signed values come
out signed;
- gen_range_u32 in a dice-roll idiom (+ 1 to shift 0..6 into 1..6),
which doubles as a hint that the helper returns a half-open range;
- string_from with three of the prebuilt charsets (ALPHANUMERIC for a
generic token, HEX_LOWER for a 128-bit-style hex string, DIGITS for
a numeric PIN), demonstrating the typical "generate me a random
identifier" use case the crate is designed for.
No library code changes; this is purely an onboarding aid. Picked an
example over expanding the crate-level rustdoc because a runnable
binary is easier to copy-paste-modify than a doctest, and Cargo's
examples/ convention is the idiomatic place for this.
Test Plan:
- `cargo run --example demo` prints one line per demonstrated API and
exits 0.
- `cargo clippy --all-targets` is clean.
ddidderr
