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use std::convert::From;
use crate::{
binding::{class, range, vm},
rubysys::range::rb_cRange,
types::Value,
AnyException, AnyObject, NilClass, Object, VerifiedObject,
};
/// `Range`
#[derive(Debug)]
#[repr(C)]
pub struct Range {
value: Value,
}
impl Range {
/// Creates `begin..end`, or `begin...end` when `exclusive` is `true`
/// (`rb_range_new`). Returns the `ArgumentError` when the bounds cannot
/// be compared with `<=>`.
///
/// # Examples
///
/// ```
/// use rutie::{Fixnum, Object, Range, RString, VM};
/// # VM::init();
///
/// let range = Range::new(&Fixnum::new(1), &Fixnum::new(5), true).unwrap();
///
/// assert_eq!(range.begin().try_convert_to::<Fixnum>(), Ok(Fixnum::new(1)));
/// assert!(range.excludes_end());
///
/// assert!(Range::new(&Fixnum::new(1), &RString::new_utf8("z"), false).is_err());
/// ```
///
/// Ruby:
///
/// ```ruby
/// 1...5
/// ```
pub fn new<B: Object, E: Object>(
begin: &B,
end: &E,
exclusive: bool,
) -> Result<Self, AnyException> {
let (begin, end) = (begin.value(), end.value());
vm::protect_value(|| range::new(begin, end, exclusive))
.map(Range::from)
.map_err(AnyException::from)
}
/// Returns the first bound (`rb_range_values`).
///
/// # Examples
///
/// ```
/// use rutie::{Fixnum, Object, Range, VM};
/// # VM::init();
///
/// let range = VM::eval("3..7").unwrap().try_convert_to::<Range>().unwrap();
///
/// assert_eq!(range.begin().try_convert_to::<Fixnum>(), Ok(Fixnum::new(3)));
/// ```
pub fn begin(&self) -> AnyObject {
self.values().0
}
/// Returns the last bound (`rb_range_values`); `nil` for an endless
/// range.
///
/// # Examples
///
/// ```
/// use rutie::{Fixnum, Object, Range, VM};
/// # VM::init();
///
/// let range = VM::eval("3..7").unwrap().try_convert_to::<Range>().unwrap();
///
/// assert_eq!(range.end().try_convert_to::<Fixnum>(), Ok(Fixnum::new(7)));
/// ```
pub fn end(&self) -> AnyObject {
self.values().1
}
/// Returns `true` for `begin...end` (Ruby's `exclude_end?`).
///
/// # Examples
///
/// ```
/// use rutie::{Object, Range, VM};
/// # VM::init();
///
/// let inclusive = VM::eval("1..2").unwrap().try_convert_to::<Range>().unwrap();
/// let exclusive = VM::eval("1...2").unwrap().try_convert_to::<Range>().unwrap();
///
/// assert!(!inclusive.excludes_end());
/// assert!(exclusive.excludes_end());
/// ```
pub fn excludes_end(&self) -> bool {
self.values().2
}
fn values(&self) -> (AnyObject, AnyObject, bool) {
let nil = NilClass::new().value();
let (begin, end, exclusive) = range::values(self.value()).unwrap_or((nil, nil, false));
(AnyObject::from(begin), AnyObject::from(end), exclusive)
}
/// Returns the `(offset, length)` this range selects from a sequence of
/// `total` elements, the way `array[range]` does (`rb_range_beg_len`):
/// negative bounds count from the end and the length is clipped.
/// `Ok(None)` when the range starts past the end, and an error when the
/// bounds are not integers.
///
/// # Examples
///
/// ```
/// use rutie::{Object, Range, VM};
/// # VM::init();
///
/// let range = VM::eval("1..-2").unwrap().try_convert_to::<Range>().unwrap();
///
/// assert_eq!(range.offset_and_length(5).unwrap(), Some((1, 3)));
///
/// let past = VM::eval("7..9").unwrap().try_convert_to::<Range>().unwrap();
///
/// assert_eq!(past.offset_and_length(5).unwrap(), None);
///
/// let letters = VM::eval("'a'..'c'").unwrap().try_convert_to::<Range>().unwrap();
///
/// assert!(letters.offset_and_length(5).is_err());
/// ```
pub fn offset_and_length(&self, total: usize) -> Result<Option<(usize, usize)>, AnyException> {
let range = self.value();
let mut result = None;
vm::protect_value(|| {
result = range::begin_length(range, total);
NilClass::new().value()
})
.map(|_| result)
.map_err(AnyException::from)
}
/// Returns `(begin, end, step, exclude_end)` of a range or an
/// arithmetic sequence such as `(1..10).step(3)`, or `None` for
/// anything else (`rb_arithmetic_sequence_extract`).
///
/// # Examples
///
/// ```
/// use rutie::{Fixnum, Object, Range, VM};
/// # VM::init();
///
/// # {
/// let sequence = VM::eval("(1..10).step(3)").unwrap();
/// let (begin, end, step, exclusive) = Range::arithmetic_sequence(&sequence).unwrap();
///
/// assert_eq!(step.try_convert_to::<Fixnum>(), Ok(Fixnum::new(3)));
/// assert!(!exclusive);
/// assert!(Range::arithmetic_sequence(&Fixnum::new(1)).is_none());
/// # }
/// ```
pub fn arithmetic_sequence<T: Object>(
object: &T,
) -> Option<(AnyObject, AnyObject, AnyObject, bool)> {
range::arithmetic_sequence(object.value()).map(|(begin, end, step, exclusive)| {
(
AnyObject::from(begin),
AnyObject::from(end),
AnyObject::from(step),
exclusive,
)
})
}
}
impl From<Value> for Range {
fn from(value: Value) -> Self {
Range { value }
}
}
impl Into<Value> for Range {
fn into(self) -> Value {
self.value
}
}
impl Into<AnyObject> for Range {
fn into(self) -> AnyObject {
AnyObject::from(self.value)
}
}
impl Object for Range {
#[inline]
fn value(&self) -> Value {
self.value
}
}
impl VerifiedObject for Range {
fn is_correct_type<T: Object>(object: &T) -> bool {
class::is_kind_of(object.value(), unsafe { rb_cRange })
}
fn error_message() -> &'static str {
"Error converting to Range"
}
}
impl PartialEq for Range {
fn eq(&self, other: &Self) -> bool {
self.equals(other)
}
}
#[cfg(test)]
mod tests {
use crate::{Fixnum, Object, RString, Range, GC, VM};
#[test]
fn test_range() {
crate::on_ruby_thread(|| {
let range = Range::new(&Fixnum::new(-3), &Fixnum::new(-1), false).unwrap();
GC::start();
assert_eq!(
range.begin().try_convert_to::<Fixnum>(),
Ok(Fixnum::new(-3))
);
assert_eq!(range.end().try_convert_to::<Fixnum>(), Ok(Fixnum::new(-1)));
assert!(!range.excludes_end());
assert_eq!(range.offset_and_length(10).unwrap(), Some((7, 3)));
assert_eq!(range.offset_and_length(2).unwrap(), None);
let empty = Range::new(&Fixnum::new(2), &Fixnum::new(2), true).unwrap();
assert_eq!(empty.offset_and_length(5).unwrap(), Some((2, 0)));
let strings =
Range::new(&RString::new_utf8("a"), &RString::new_utf8("e"), true).unwrap();
assert!(strings.offset_and_length(3).is_err());
let from_ruby = VM::eval("(1..4)").unwrap();
assert!(from_ruby.try_convert_to::<Range>().is_ok());
// A Struct is not a Range, although Ruby stores ranges as structs.
assert!(VM::eval("Struct.new(:a).new(1)")
.unwrap()
.try_convert_to::<Range>()
.is_err());
});
}
#[test]
fn test_endless_range_and_arithmetic_sequence() {
crate::on_ruby_thread(|| {
let endless = VM::eval("(3..)")
.unwrap()
.try_convert_to::<Range>()
.unwrap();
assert!(endless.end().is_nil());
assert_eq!(endless.offset_and_length(5).unwrap(), Some((3, 2)));
let (begin, end, step, exclusive) =
Range::arithmetic_sequence(&VM::eval("(0...9).step(2)").unwrap()).unwrap();
assert_eq!(begin.try_convert_to::<Fixnum>(), Ok(Fixnum::new(0)));
assert_eq!(end.try_convert_to::<Fixnum>(), Ok(Fixnum::new(9)));
assert_eq!(step.try_convert_to::<Fixnum>(), Ok(Fixnum::new(2)));
assert!(exclusive);
});
}
}