498 lines
15 KiB
Rust

use std::fmt::{Debug, Formatter};
use std::hash::{Hash, Hasher};
use std::ops::{Add, AddAssign};
use std::sync::Arc;
use comemo::Tracked;
use ecow::{eco_format, EcoString};
use indexmap::IndexMap;
use serde::{Deserialize, Deserializer, Serialize, Serializer};
use typst_syntax::is_ident;
use typst_utils::ArcExt;
use crate::diag::{Hint, HintedStrResult, SourceResult, StrResult};
use crate::engine::Engine;
use crate::foundations::{
array, cast, func, repr, scope, ty, Array, Context, Func, Module, Repr, Str, Value,
};
/// Create a new [`Dict`] from key-value pairs.
#[macro_export]
#[doc(hidden)]
macro_rules! __dict {
($($key:expr => $value:expr),* $(,)?) => {{
#[allow(unused_mut)]
let mut map = $crate::foundations::IndexMap::new();
$(map.insert($key.into(), $crate::foundations::IntoValue::into_value($value));)*
$crate::foundations::Dict::from(map)
}};
}
#[doc(inline)]
pub use crate::__dict as dict;
/// A map from string keys to values.
///
/// You can construct a dictionary by enclosing comma-separated `key: value`
/// pairs in parentheses. The values do not have to be of the same type. Since
/// empty parentheses already yield an empty array, you have to use the special
/// `(:)` syntax to create an empty dictionary.
///
/// A dictionary is conceptually similar to an array, but it is indexed by
/// strings instead of integers. You can access and create dictionary entries
/// with the `.at()` method. If you know the key statically, you can
/// alternatively use [field access notation]($scripting/#fields) (`.key`) to
/// access the value. Dictionaries can be added with the `+` operator and
/// [joined together]($scripting/#blocks). To check whether a key is present in
/// the dictionary, use the `in` keyword.
///
/// You can iterate over the pairs in a dictionary using a [for
/// loop]($scripting/#loops). This will iterate in the order the pairs were
/// inserted / declared.
///
/// # Example
/// ```example
/// #let dict = (
/// name: "Typst",
/// born: 2019,
/// )
///
/// #dict.name \
/// #(dict.launch = 20)
/// #dict.len() \
/// #dict.keys() \
/// #dict.values() \
/// #dict.at("born") \
/// #dict.insert("city", "Berlin ")
/// #("name" in dict)
/// ```
#[ty(scope, cast, name = "dictionary")]
#[derive(Default, Clone, PartialEq)]
pub struct Dict(Arc<IndexMap<Str, Value>>);
impl Dict {
/// Create a new, empty dictionary.
pub fn new() -> Self {
Self::default()
}
/// Whether the dictionary is empty.
pub fn is_empty(&self) -> bool {
self.0.is_empty()
}
/// Borrow the value at the given key.
pub fn get(&self, key: &str) -> StrResult<&Value> {
self.0.get(key).ok_or_else(|| missing_key(key))
}
/// Mutably borrow the value the given `key` maps to.
pub fn at_mut(&mut self, key: &str) -> HintedStrResult<&mut Value> {
Arc::make_mut(&mut self.0)
.get_mut(key)
.ok_or_else(|| missing_key(key))
.hint("use `insert` to add or update values")
}
/// Remove the value if the dictionary contains the given key.
pub fn take(&mut self, key: &str) -> StrResult<Value> {
Arc::make_mut(&mut self.0)
.shift_remove(key)
.ok_or_else(|| missing_key(key))
}
/// Whether the dictionary contains a specific key.
pub fn contains(&self, key: &str) -> bool {
self.0.contains_key(key)
}
/// Clear the dictionary.
pub fn clear(&mut self) {
if Arc::strong_count(&self.0) == 1 {
Arc::make_mut(&mut self.0).clear();
} else {
*self = Self::new();
}
}
/// Iterate over pairs of references to the contained keys and values.
pub fn iter(&self) -> indexmap::map::Iter<Str, Value> {
self.0.iter()
}
/// Check if there is any remaining pair, and if so return an
/// "unexpected key" error.
pub fn finish(&self, expected: &[&str]) -> StrResult<()> {
let mut iter = self.iter().peekable();
if iter.peek().is_none() {
return Ok(());
}
let unexpected: Vec<&str> = iter.map(|kv| kv.0.as_str()).collect();
Err(Self::unexpected_keys(unexpected, Some(expected)))
}
// Return an "unexpected key" error string.
pub fn unexpected_keys(
unexpected: Vec<&str>,
hint_expected: Option<&[&str]>,
) -> EcoString {
let format_as_list = |arr: &[&str]| {
repr::separated_list(
&arr.iter().map(|s| eco_format!("\"{s}\"")).collect::<Vec<_>>(),
"and",
)
};
let mut msg = String::from(match unexpected.len() {
1 => "unexpected key ",
_ => "unexpected keys ",
});
msg.push_str(&format_as_list(&unexpected[..]));
if let Some(expected) = hint_expected {
msg.push_str(", valid keys are ");
msg.push_str(&format_as_list(expected));
}
msg.into()
}
}
#[scope]
impl Dict {
/// Converts a value into a dictionary.
///
/// Note that this function is only intended for conversion of a
/// dictionary-like value to a dictionary, not for creation of a dictionary
/// from individual pairs. Use the dictionary syntax `(key: value)` instead.
///
/// ```example
/// #dictionary(sys).at("version")
/// ```
#[func(constructor)]
pub fn construct(
/// The value that should be converted to a dictionary.
value: ToDict,
) -> Dict {
value.0
}
/// The number of pairs in the dictionary.
#[func(title = "Length")]
pub fn len(&self) -> usize {
self.0.len()
}
/// Returns the value associated with the specified key in the dictionary.
/// May be used on the left-hand side of an assignment if the key is already
/// present in the dictionary. Returns the default value if the key is not
/// part of the dictionary or fails with an error if no default value was
/// specified.
#[func]
pub fn at(
&self,
/// The key at which to retrieve the item.
key: Str,
/// A default value to return if the key is not part of the dictionary.
#[named]
default: Option<Value>,
) -> StrResult<Value> {
self.0
.get(&key)
.cloned()
.or(default)
.ok_or_else(|| missing_key_no_default(&key))
}
/// Inserts a new pair into the dictionary. If the dictionary already
/// contains this key, the value is updated.
#[func]
pub fn insert(
&mut self,
/// The key of the pair that should be inserted.
key: Str,
/// The value of the pair that should be inserted.
value: Value,
) {
Arc::make_mut(&mut self.0).insert(key, value);
}
/// Removes a pair from the dictionary by key and return the value.
#[func]
pub fn remove(
&mut self,
/// The key of the pair to remove.
key: Str,
/// A default value to return if the key does not exist.
#[named]
default: Option<Value>,
) -> StrResult<Value> {
Arc::make_mut(&mut self.0)
.shift_remove(&key)
.or(default)
.ok_or_else(|| missing_key(&key))
}
/// Returns the keys of the dictionary as an array in insertion order.
#[func]
pub fn keys(&self) -> Array {
self.0.keys().cloned().map(Value::Str).collect()
}
/// Returns the values of the dictionary as an array in insertion order.
#[func]
pub fn values(&self) -> Array {
self.0.values().cloned().collect()
}
/// Returns the keys and values of the dictionary as an array of pairs. Each
/// pair is represented as an array of length two.
#[func]
pub fn pairs(&self) -> Array {
self.0
.iter()
.map(|(k, v)| Value::Array(array![k.clone(), v.clone()]))
.collect()
}
/// Produces a new dictionary or array by transforming each key-value pair with the given function.
///
/// If the mapper function returns a pair (array of length 2), the result will be a new dictionary.
/// Otherwise, the result will be an array containing all mapped values.
///
/// ```example
/// #let prices = (apples: 2, oranges: 3, bananas: 1.5)
/// #prices.map(pair => pair.at(0).len())
/// #prices.map((key, value) => (key, value * 1.1))
/// ```
#[func]
pub fn map(
self,
engine: &mut Engine,
context: Tracked<Context>,
/// The function to apply to each key-value pair.
/// The function can either take a single parameter (receiving a pair as array of length 2),
/// or two parameters (receiving key and value separately).
/// Parameters exceeding two will be ignored.
mapper: Func,
) -> SourceResult<Value> {
let mut dict_result = IndexMap::new();
let mut array_result = Vec::new();
let mut is_dict = true;
// try to check the number of parameters, if not, use array form
let mut first_pair = true;
let mut use_single_arg = false;
for (key, value) in self {
let mapped = if first_pair {
// try two calling ways for the first pair
first_pair = false;
// try to call with two parameters
let result = mapper.call(
engine,
context,
[Value::Str(key.clone()), value.clone()],
);
// if failed, try to call with one parameter
if result.is_err() {
use_single_arg = true;
mapper.call(
engine,
context,
[Value::Array(array![Value::Str(key.clone()), value])],
)?
} else {
result?
}
} else if use_single_arg {
// try to call with one parameter
mapper.call(
engine,
context,
[Value::Array(array![Value::Str(key.clone()), value])],
)?
} else {
// try to call with two parameters
mapper.call(engine, context, [Value::Str(key.clone()), value.clone()])?
};
// check if the result is a dictionary key-value pair
if let Value::Array(arr) = &mapped {
if arr.len() == 2 {
if let Value::Str(k) = &arr.as_slice()[0] {
if is_dict {
dict_result.insert(k.clone(), arr.as_slice()[1].clone());
continue;
}
}
}
}
// if the result is not a key-value pair, switch the result type to array
if is_dict {
is_dict = false;
// convert the collected dictionary result to array items
for (k, v) in dict_result.drain(..) {
array_result.push(Value::Array(array![Value::Str(k), v]));
}
}
array_result.push(mapped);
}
if is_dict {
Ok(Value::Dict(Dict::from(dict_result)))
} else {
Ok(Value::Array(array_result.into_iter().collect()))
}
}
}
/// A value that can be cast to dictionary.
pub struct ToDict(Dict);
cast! {
ToDict,
v: Module => Self(v
.scope()
.iter()
.map(|(k, b)| (Str::from(k.clone()), b.read().clone()))
.collect()
),
}
impl Debug for Dict {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
f.debug_map().entries(self.0.iter()).finish()
}
}
impl Repr for Dict {
fn repr(&self) -> EcoString {
if self.is_empty() {
return "(:)".into();
}
let max = 40;
let mut pieces: Vec<_> = self
.iter()
.take(max)
.map(|(key, value)| {
if is_ident(key) {
eco_format!("{key}: {}", value.repr())
} else {
eco_format!("{}: {}", key.repr(), value.repr())
}
})
.collect();
if self.len() > max {
pieces.push(eco_format!(".. ({} pairs omitted)", self.len() - max));
}
repr::pretty_array_like(&pieces, false).into()
}
}
impl Add for Dict {
type Output = Self;
fn add(mut self, rhs: Dict) -> Self::Output {
self += rhs;
self
}
}
impl AddAssign for Dict {
fn add_assign(&mut self, rhs: Dict) {
match Arc::try_unwrap(rhs.0) {
Ok(map) => self.extend(map),
Err(rc) => self.extend(rc.iter().map(|(k, v)| (k.clone(), v.clone()))),
}
}
}
impl Hash for Dict {
fn hash<H: Hasher>(&self, state: &mut H) {
state.write_usize(self.0.len());
for item in self {
item.hash(state);
}
}
}
impl Serialize for Dict {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
self.0.serialize(serializer)
}
}
impl<'de> Deserialize<'de> for Dict {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
Ok(IndexMap::<Str, Value>::deserialize(deserializer)?.into())
}
}
impl Extend<(Str, Value)> for Dict {
fn extend<T: IntoIterator<Item = (Str, Value)>>(&mut self, iter: T) {
Arc::make_mut(&mut self.0).extend(iter);
}
}
impl FromIterator<(Str, Value)> for Dict {
fn from_iter<T: IntoIterator<Item = (Str, Value)>>(iter: T) -> Self {
Self(Arc::new(iter.into_iter().collect()))
}
}
impl IntoIterator for Dict {
type Item = (Str, Value);
type IntoIter = indexmap::map::IntoIter<Str, Value>;
fn into_iter(self) -> Self::IntoIter {
Arc::take(self.0).into_iter()
}
}
impl<'a> IntoIterator for &'a Dict {
type Item = (&'a Str, &'a Value);
type IntoIter = indexmap::map::Iter<'a, Str, Value>;
fn into_iter(self) -> Self::IntoIter {
self.iter()
}
}
impl From<IndexMap<Str, Value>> for Dict {
fn from(map: IndexMap<Str, Value>) -> Self {
Self(Arc::new(map))
}
}
/// The missing key access error message.
#[cold]
fn missing_key(key: &str) -> EcoString {
eco_format!("dictionary does not contain key {}", key.repr())
}
/// The missing key access error message when no default was given.
#[cold]
fn missing_key_no_default(key: &str) -> EcoString {
eco_format!(
"dictionary does not contain key {} \
and no default value was specified",
key.repr()
)
}