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use std::ptr::null;
use std::mem::transmute;
use libc::c_int;
use onig_sys;
use super::CaptureTreeNode;
/// Represents a set of capture groups found in a search or match.
#[derive(Debug)]
pub struct Region {
raw: onig_sys::OnigRegion,
}
impl Region {
/// Create a new empty `Region`
pub fn new() -> Region {
Region {
raw: onig_sys::OnigRegion {
allocated: 0,
num_regs: 0,
beg: null(),
end: null(),
history_root: null()
}
}
}
/// Create a new region with a given capacity. This function allocates
/// a new region object as in `Region::new` and resizes it to
/// contain at least `capacity` regions.
///
/// # Arguments
///
/// * `capacity` - the number of captures this region should be
/// capable of storing without allocation.
pub fn with_capacity(capacity: usize) -> Region {
let mut region = Self::new();
region.reserve(capacity);
region
}
/// This can be used to clear out a region so it can be used
/// again. See [`onig_sys::onig_region_clear`][region_clear]
///
/// [region_clear]: ./onig_sys/fn.onig_region_clear.html
pub fn clear(&mut self) {
unsafe {
onig_sys::onig_region_clear(&self.raw);
}
}
pub fn capacity(&self) -> usize {
self.raw.allocated as usize
}
/// Updates the region to contain `new_capacity` slots. See
/// [`onig_sys::onig_region_resize`][region_resize] for mor
/// information.
///
/// [region_resize]: ./onig_sys/fn.onig_region_resize.html
///
/// # Arguments
///
/// * `new_capacity` - The new number of groups in the region.
pub fn reserve(&mut self, new_capacity: usize) {
let r = unsafe {
onig_sys::onig_region_resize(&self.raw, new_capacity as c_int)
};
if r != 0 {
panic!("Onig: fail to memory allocation during region resize")
}
}
/// Get the size of the region. Returns the number of registers in
/// the region.
pub fn len(&self) -> usize {
self.raw.num_regs as usize
}
/// Returns the start and end positions of the Nth capture group. Returns
/// `None` if `pos` is not a valid capture group or if the capture group did
/// not match anything. The positions returned are always byte indices with
/// respect to the original string matched.
pub fn pos(&self, pos: usize) -> Option<(usize, usize)> {
if pos >= self.len() {
return None
}
let (beg, end) = unsafe {
(
*self.raw.beg.offset(pos as isize),
*self.raw.end.offset(pos as isize)
)
};
if beg >= 0 {
Some((beg as usize, end as usize))
} else {
None
}
}
pub fn tree(&self) -> Option<&CaptureTreeNode> {
let tree = unsafe {
onig_sys::onig_get_capture_tree(&self.raw)
};
if tree.is_null() {
None
} else {
Some(unsafe { transmute(tree) })
}
}
}
impl Drop for Region {
fn drop(&mut self) {
unsafe {
onig_sys::onig_region_free(&mut self.raw, 0);
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_region_create() {
Region::new();
}
#[test]
fn test_region_clear() {
let mut region = Region::new();
region.clear();
}
#[test]
fn test_region_resize() {
{
let mut region = Region::new();
assert!(region.capacity() == 0);
region.reserve(100);
{
// can still get the capacity without a mutable borrow
let region_borrowed = ®ion;
assert!(region_borrowed.capacity() == 100);
}
}
{
let region = Region::with_capacity(10);
assert!(region.capacity() == 10);
}
}
}