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use super::Key;
use crate::traitdef::{Mutable, Value};
use std::mem;
use yaml_rust::{yaml::Hash, Yaml, YamlEmitter, YamlLoader};
fn from_str(s: &str) -> Yaml {
let mut v = YamlLoader::load_from_str(s)
.expect("valid yaml value - we serialized it beforehand after all");
assert_eq!(
v.len(),
1,
"need exactly one document - multi-document keys are just not possible"
);
v.pop().unwrap()
}
fn to_string(v: &Yaml) -> String {
let mut buf = String::new();
YamlEmitter::new(&mut buf)
.dump(v)
.expect("valid yaml value");
buf[4..].to_owned()
}
impl Value for Yaml {
type Key = Key;
type Item = Yaml;
fn items<'a>(&'a self) -> Option<Box<dyn Iterator<Item = (Self::Key, &'a Self::Item)> + 'a>> {
match *self {
Yaml::String(_)
| Yaml::Integer(_)
| Yaml::Real(_)
| Yaml::Boolean(_)
| Yaml::Null
| Yaml::Alias(_)
| Yaml::BadValue => None,
Yaml::Array(ref inner) => Some(Box::new(
inner.iter().enumerate().map(|(i, v)| (Key::Index(i), v)),
)),
Yaml::Hash(ref inner) => Some(Box::new(
inner.iter().map(|(k, v)| (Key::String(to_string(k)), v)),
)),
}
}
}
impl Mutable for Yaml {
type Key = Key;
type Item = Yaml;
fn set(&mut self, keys: &[Self::Key], v: &Self::Item) {
if keys.is_empty() {
*self = v.clone();
} else {
let mut c = self;
let last_key_index = keys.len() - 1;
let object_or_value = |index| {
if index == last_key_index {
v.clone()
} else {
Yaml::Hash(Hash::new())
}
};
fn runup_array_or_value<'a>(
array: &'a mut Vec<Yaml>,
target_index: usize,
key_index: usize,
last_key_index: usize,
v: &Yaml,
) -> &'a mut Yaml {
for _ in array.len()..target_index {
array.push(Yaml::Null);
}
let value = if key_index == last_key_index {
v.clone()
} else {
Yaml::Null
};
if target_index == array.len() {
array.push(value);
} else {
array[target_index] = value;
}
&mut array[target_index]
}
for (i, k) in keys.iter().enumerate() {
c = match *k {
Key::String(ref k) => {
let k = from_str(&k);
match { c } {
&mut Yaml::Hash(ref mut obj) => {
if obj.contains_key(&k) {
let obj = obj.get_mut(&k).expect("map to work");
if i == last_key_index {
*obj = v.clone();
return;
}
obj
} else {
obj.insert(k.clone(), object_or_value(i));
obj.get_mut(&k).expect("map to work")
}
}
c @ &mut Yaml::String(_)
| c @ &mut Yaml::Integer(_)
| c @ &mut Yaml::Real(_)
| c @ &mut Yaml::Boolean(_)
| c @ &mut Yaml::Null
| c @ &mut Yaml::Alias(_)
| c @ &mut Yaml::BadValue
| c @ &mut Yaml::Array(_) => {
drop(mem::replace(
c,
Yaml::Hash({
let mut o = Hash::new();
o.insert(k.clone(), object_or_value(i));
o
}),
));
if i == last_key_index {
return;
}
match c {
Yaml::Hash(ref mut obj) => {
obj.get_mut(&k).expect("previous insertion")
}
_ => unreachable!(),
}
}
}
}
Key::Index(idx) => match { c } {
&mut Yaml::Array(ref mut a) => {
runup_array_or_value(a, idx, i, last_key_index, v)
}
c @ &mut Yaml::String(_)
| c @ &mut Yaml::Alias(_)
| c @ &mut Yaml::BadValue
| c @ &mut Yaml::Integer(_)
| c @ &mut Yaml::Real(_)
| c @ &mut Yaml::Boolean(_)
| c @ &mut Yaml::Null
| c @ &mut Yaml::Hash(_) => {
let mut a = Vec::new();
runup_array_or_value(&mut a, idx, i, last_key_index, v);
drop(mem::replace(c, Yaml::Array(a)));
if i == last_key_index {
return;
}
match c {
Yaml::Array(ref mut a) => {
a.get_mut(idx).expect("previous insertion")
}
_ => unreachable!(),
}
}
},
}
}
}
}
fn remove(&mut self, keys: &[Self::Key]) {
let mut c = self;
let last_key_index = keys.len().checked_sub(1).expect("at least one key");
for (i, k) in keys.iter().enumerate() {
c = match *k {
Key::String(ref k) => {
let k = from_str(&k);
match { c } {
Yaml::Hash(ref mut obj) => {
if i == last_key_index {
obj.remove(&k);
return;
} else {
match obj.get_mut(&k) {
Some(json) => json,
None => return,
}
}
}
_ => return,
}
}
Key::Index(idx) => match { c } {
Yaml::Array(ref mut a) => {
if i == last_key_index {
a.remove(idx);
return;
} else {
match a.get_mut(idx) {
Some(json) => json,
None => return,
}
}
}
_ => return,
},
}
}
}
}