Merge pull request #88 from BourgondAries/master

Add lookup_mut method for mutable access
This commit is contained in:
Alex Crichton 2016-03-25 14:11:45 -07:00
commit b0a134a1d9

View file

@ -206,6 +206,62 @@ impl Value {
Some(cur_value)
}
/// Lookups for mutable value at specified path.
///
/// Uses '.' as a path separator.
///
/// Note: arrays have zero-based indexes.
///
/// Note: empty path returns self.
///
/// ```
/// # #![allow(unstable)]
/// let toml = r#"
/// [test]
/// foo = "bar"
///
/// [[values]]
/// foo = "baz"
///
/// [[values]]
/// foo = "qux"
/// "#;
/// let mut value: toml::Value = toml.parse().unwrap();
/// {
/// let string = value.lookup_mut("test.foo").unwrap();
/// assert_eq!(string, &mut toml::Value::String(String::from("bar")));
/// *string = toml::Value::String(String::from("foo"));
/// }
/// let result = value.lookup_mut("test.foo").unwrap();
/// assert_eq!(result.as_str().unwrap(), "foo");
/// ```
pub fn lookup_mut(&mut self, path: &str) -> Option<&mut Value> {
let mut cur = self;
if path.len() == 0 {
return Some(cur)
}
for key in path.split('.') {
let tmp = cur;
match *tmp {
Value::Table(ref mut hm) => {
match hm.get_mut(key) {
Some(v) => cur = v,
None => return None
}
}
Value::Array(ref mut v) => {
match key.parse::<usize>().ok() {
Some(idx) if idx < v.len() => cur = &mut v[idx],
_ => return None
}
}
_ => return None
}
}
Some(cur)
}
}
impl FromStr for Value {
@ -223,6 +279,98 @@ impl FromStr for Value {
mod tests {
use super::Value;
#[test]
fn lookup_mut_change() {
let toml = r#"
[test]
foo = "bar"
[[values]]
foo = "baz"
[[values]]
foo = "qux"
"#;
let mut value: Value = toml.parse().unwrap();
{
let foo = value.lookup_mut("values.0.foo").unwrap();
*foo = Value::String(String::from("bar"));
}
let foo = value.lookup("values.0.foo").unwrap();
assert_eq!(foo.as_str().unwrap(), "bar");
}
#[test]
fn lookup_mut_valid() {
let toml = r#"
[test]
foo = "bar"
[[values]]
foo = "baz"
[[values]]
foo = "qux"
"#;
let mut value: Value = toml.parse().unwrap();
{
let test_foo = value.lookup_mut("test.foo").unwrap();
assert_eq!(test_foo.as_str().unwrap(), "bar");
}
{
let foo1 = value.lookup_mut("values.1.foo").unwrap();
assert_eq!(foo1.as_str().unwrap(), "qux");
}
assert!(value.lookup_mut("test.bar").is_none());
assert!(value.lookup_mut("test.foo.bar").is_none());
}
#[test]
fn lookup_mut_invalid_index() {
let toml = r#"
[[values]]
foo = "baz"
"#;
let mut value: Value = toml.parse().unwrap();
{
let foo = value.lookup_mut("test.foo");
assert!(foo.is_none());
}
{
let foo = value.lookup_mut("values.100.foo");
assert!(foo.is_none());
}
{
let foo = value.lookup_mut("values.str.foo");
assert!(foo.is_none());
}
}
#[test]
fn lookup_mut_self() {
let mut value: Value = r#"foo = "bar""#.parse().unwrap();
{
let foo = value.lookup_mut("foo").unwrap();
assert_eq!(foo.as_str().unwrap(), "bar");
}
let foo = value.lookup_mut("").unwrap();
assert!(foo.as_table().is_some());
let baz = foo.lookup_mut("foo").unwrap();
assert_eq!(baz.as_str().unwrap(), "bar");
}
#[test]
fn lookup_valid() {
let toml = r#"