minijinja/filters.rs
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//! Filter functions and abstractions.
//!
//! MiniJinja inherits from Jinja2 the concept of filter functions. These are functions
//! which are applied to values to modify them. For example the expression `{{ 42|filter(23) }}`
//! invokes the filter `filter` with the arguments `42` and `23`.
//!
//! MiniJinja comes with some built-in filters that are listed below. To create a
//! custom filter write a function that takes at least a value, then registers it
//! with [`add_filter`](crate::Environment::add_filter).
//!
//! # Using Filters
//!
//! Using filters in templates is possible in all places an expression is permitted.
//! This means they are not just used for printing but also are useful for iteration
//! or similar situations.
//!
//! Motivating example:
//!
//! ```jinja
//! <dl>
//! {% for key, value in config|items %}
//! <dt>{{ key }}
//! <dd><pre>{{ value|tojson }}</pre>
//! {% endfor %}
//! </dl>
//! ```
//!
//! # Custom Filters
//!
//! A custom filter is just a simple function which accepts its inputs
//! as parameters and then returns a new value. For instance the following
//! shows a filter which takes an input value and replaces whitespace with
//! dashes and converts it to lowercase:
//!
//! ```
//! # use minijinja::Environment;
//! # let mut env = Environment::new();
//! fn slugify(value: String) -> String {
//! value.to_lowercase().split_whitespace().collect::<Vec<_>>().join("-")
//! }
//!
//! env.add_filter("slugify", slugify);
//! ```
//!
//! MiniJinja will perform the necessary conversions automatically. For more
//! information see the [`Filter`] trait.
//!
//! # Accessing State
//!
//! In some cases it can be necessary to access the execution [`State`]. Since a borrowed
//! state implements [`ArgType`] it's possible to add a parameter that holds the state.
//! For instance the following filter appends the current template name to the string:
//!
//! ```
//! # use minijinja::Environment;
//! # let mut env = Environment::new();
//! use minijinja::{Value, State};
//!
//! fn append_template(state: &State, value: &Value) -> String {
//! format!("{}-{}", value, state.name())
//! }
//!
//! env.add_filter("append_template", append_template);
//! ```
//!
//! # Filter configuration
//!
//! The recommended pattern for filters to change their behavior is to leverage global
//! variables in the template. For instance take a filter that performs date formatting.
//! You might want to change the default time format format on a per-template basis
//! without having to update every filter invocation. In this case the recommended
//! pattern is to reserve upper case variables and look them up in the filter:
//!
//! ```
//! # use minijinja::Environment;
//! # let mut env = Environment::new();
//! # fn format_unix_timestamp(_: f64, _: &str) -> String { "".into() }
//! use minijinja::State;
//!
//! fn timeformat(state: &State, ts: f64) -> String {
//! let configured_format = state.lookup("TIME_FORMAT");
//! let format = configured_format
//! .as_ref()
//! .and_then(|x| x.as_str())
//! .unwrap_or("HH:MM:SS");
//! format_unix_timestamp(ts, format)
//! }
//!
//! env.add_filter("timeformat", timeformat);
//! ```
//!
//! This then later lets a user override the default either by using
//! [`add_global`](crate::Environment::add_global) or by passing it with the
//! [`context!`] macro or similar.
//!
//! ```
//! # use minijinja::context;
//! # let other_variables = context!{};
//! let ctx = context! {
//! TIME_FORMAT => "HH:MM",
//! ..other_variables
//! };
//! ```
//!
//! # Built-in Filters
//!
//! When the `builtins` feature is enabled a range of built-in filters are
//! automatically added to the environment. These are also all provided in
//! this module. Note though that these functions are not to be
//! called from Rust code as their exact interface (arguments and return types)
//! might change from one MiniJinja version to another.
//!
//! Some additional filters are available in the
//! [`minijinja-contrib`](https://crates.io/crates/minijinja-contrib) crate.
use std::sync::Arc;
use crate::error::Error;
use crate::utils::{write_escaped, SealedMarker};
use crate::value::{ArgType, FunctionArgs, FunctionResult, Value};
use crate::vm::State;
use crate::{AutoEscape, Output};
type FilterFunc = dyn Fn(&State, &[Value]) -> Result<Value, Error> + Sync + Send + 'static;
#[derive(Clone)]
pub(crate) struct BoxedFilter(Arc<FilterFunc>);
/// A utility trait that represents filters.
///
/// This trait is used by the [`add_filter`](crate::Environment::add_filter) method to abstract over
/// different types of functions that implement filters. Filters are functions
/// which at the very least accept the [`State`] by reference as first parameter
/// and the value that that the filter is applied to as second. Additionally up to
/// 4 further parameters are supported.
///
/// A filter can return any of the following types:
///
/// * `Rv` where `Rv` implements `Into<Value>`
/// * `Result<Rv, Error>` where `Rv` implements `Into<Value>`
///
/// Filters accept one mandatory parameter which is the value the filter is
/// applied to and up to 4 extra parameters. The extra parameters can be
/// marked optional by using `Option<T>`. The last argument can also use
/// [`Rest<T>`](crate::value::Rest) to capture the remaining arguments. All
/// types are supported for which [`ArgType`] is implemented.
///
/// For a list of built-in filters see [`filters`](crate::filters).
///
/// # Basic Example
///
/// ```
/// # use minijinja::Environment;
/// # let mut env = Environment::new();
/// use minijinja::State;
///
/// fn slugify(value: String) -> String {
/// value.to_lowercase().split_whitespace().collect::<Vec<_>>().join("-")
/// }
///
/// env.add_filter("slugify", slugify);
/// ```
///
/// ```jinja
/// {{ "Foo Bar Baz"|slugify }} -> foo-bar-baz
/// ```
///
/// # Arguments and Optional Arguments
///
/// ```
/// # use minijinja::Environment;
/// # let mut env = Environment::new();
/// fn substr(value: String, start: u32, end: Option<u32>) -> String {
/// let end = end.unwrap_or(value.len() as _);
/// value.get(start as usize..end as usize).unwrap_or_default().into()
/// }
///
/// env.add_filter("substr", substr);
/// ```
///
/// ```jinja
/// {{ "Foo Bar Baz"|substr(4) }} -> Bar Baz
/// {{ "Foo Bar Baz"|substr(4, 7) }} -> Bar
/// ```
///
/// # Variadic
///
/// ```
/// # use minijinja::Environment;
/// # let mut env = Environment::new();
/// use minijinja::value::Rest;
///
/// fn pyjoin(joiner: String, values: Rest<String>) -> String {
/// values.join(&joiner)
/// }
///
/// env.add_filter("pyjoin", pyjoin);
/// ```
///
/// ```jinja
/// {{ "|".join(1, 2, 3) }} -> 1|2|3
/// ```
pub trait Filter<Rv, Args>: Send + Sync + 'static {
/// Applies a filter to value with the given arguments.
///
/// The value is always the first argument.
#[doc(hidden)]
fn apply_to(&self, args: Args, _: SealedMarker) -> Rv;
}
macro_rules! tuple_impls {
( $( $name:ident )* ) => {
impl<Func, Rv, $($name),*> Filter<Rv, ($($name,)*)> for Func
where
Func: Fn($($name),*) -> Rv + Send + Sync + 'static,
Rv: FunctionResult,
$($name: for<'a> ArgType<'a>,)*
{
fn apply_to(&self, args: ($($name,)*), _: SealedMarker) -> Rv {
#[allow(non_snake_case)]
let ($($name,)*) = args;
(self)($($name,)*)
}
}
};
}
tuple_impls! {}
tuple_impls! { A }
tuple_impls! { A B }
tuple_impls! { A B C }
tuple_impls! { A B C D }
tuple_impls! { A B C D E }
impl BoxedFilter {
/// Creates a new boxed filter.
pub fn new<F, Rv, Args>(f: F) -> BoxedFilter
where
F: Filter<Rv, Args> + for<'a> Filter<Rv, <Args as FunctionArgs<'a>>::Output>,
Rv: FunctionResult,
Args: for<'a> FunctionArgs<'a>,
{
BoxedFilter(Arc::new(move |state, args| -> Result<Value, Error> {
f.apply_to(ok!(Args::from_values(Some(state), args)), SealedMarker)
.into_result()
}))
}
/// Applies the filter to a value and argument.
pub fn apply_to(&self, state: &State, args: &[Value]) -> Result<Value, Error> {
(self.0)(state, args)
}
}
/// Marks a value as safe. This converts it into a string.
///
/// When a value is marked as safe, no further auto escaping will take place.
pub fn safe(v: String) -> Value {
Value::from_safe_string(v)
}
/// Escapes a string. By default to HTML.
///
/// By default this filter is also registered under the alias `e`. Note that
/// this filter escapes with the format that is native to the format or HTML
/// otherwise. This means that if the auto escape setting is set to
/// `Json` for instance then this filter will serialize to JSON instead.
pub fn escape(state: &State, v: Value) -> Result<Value, Error> {
if v.is_safe() {
return Ok(v);
}
// this tries to use the escaping flag of the current scope, then
// of the initial state and if that is also not set it falls back
// to HTML.
let auto_escape = match state.auto_escape() {
AutoEscape::None => match state.env().initial_auto_escape(state.name()) {
AutoEscape::None => AutoEscape::Html,
other => other,
},
other => other,
};
let mut rv = match v.as_str() {
Some(s) => String::with_capacity(s.len()),
None => String::new(),
};
let mut out = Output::with_string(&mut rv);
ok!(write_escaped(&mut out, auto_escape, &v));
Ok(Value::from_safe_string(rv))
}
#[cfg(feature = "builtins")]
mod builtins {
use super::*;
use crate::error::ErrorKind;
use crate::utils::splitn_whitespace;
use crate::value::ops::as_f64;
use crate::value::{Enumerator, Kwargs, Object, ObjectRepr, ValueKind, ValueRepr};
use std::borrow::Cow;
use std::cmp::Ordering;
use std::fmt::Write;
use std::mem;
/// Converts a value to uppercase.
///
/// ```jinja
/// <h1>{{ chapter.title|upper }}</h1>
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn upper(v: Cow<'_, str>) -> String {
v.to_uppercase()
}
/// Converts a value to lowercase.
///
/// ```jinja
/// <h1>{{ chapter.title|lower }}</h1>
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn lower(v: Cow<'_, str>) -> String {
v.to_lowercase()
}
/// Converts a value to title case.
///
/// ```jinja
/// <h1>{{ chapter.title|title }}</h1>
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn title(v: Cow<'_, str>) -> String {
let mut rv = String::new();
let mut capitalize = true;
for c in v.chars() {
if c.is_ascii_punctuation() || c.is_whitespace() {
rv.push(c);
capitalize = true;
} else if capitalize {
write!(rv, "{}", c.to_uppercase()).unwrap();
capitalize = false;
} else {
write!(rv, "{}", c.to_lowercase()).unwrap();
}
}
rv
}
/// Convert the string with all its characters lowercased
/// apart from the first char which is uppercased.
///
/// ```jinja
/// <h1>{{ chapter.title|capitalize }}</h1>
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn capitalize(text: Cow<'_, str>) -> String {
let mut chars = text.chars();
match chars.next() {
None => String::new(),
Some(f) => f.to_uppercase().collect::<String>() + &chars.as_str().to_lowercase(),
}
}
/// Does a string replace.
///
/// It replaces all occurrences of the first parameter with the second.
///
/// ```jinja
/// {{ "Hello World"|replace("Hello", "Goodbye") }}
/// -> Goodbye World
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn replace(
_state: &State,
v: Cow<'_, str>,
from: Cow<'_, str>,
to: Cow<'_, str>,
) -> String {
v.replace(&from as &str, &to as &str)
}
/// Returns the "length" of the value
///
/// By default this filter is also registered under the alias `count`.
///
/// ```jinja
/// <p>Search results: {{ results|length }}
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn length(v: Value) -> Result<usize, Error> {
v.len().ok_or_else(|| {
Error::new(
ErrorKind::InvalidOperation,
format!("cannot calculate length of value of type {}", v.kind()),
)
})
}
fn cmp_helper(a: &Value, b: &Value, case_sensitive: bool) -> Ordering {
if !case_sensitive {
if let (Some(a), Some(b)) = (a.as_str(), b.as_str()) {
#[cfg(feature = "unicode")]
{
return unicase::UniCase::new(a).cmp(&unicase::UniCase::new(b));
}
#[cfg(not(feature = "unicode"))]
{
return a.to_ascii_lowercase().cmp(&b.to_ascii_lowercase());
}
}
}
a.cmp(b)
}
/// Dict sorting functionality.
///
/// This filter works like `|items` but sorts the pairs by key first.
///
/// The filter accepts a few keyword arguments:
///
/// * `case_sensitive`: set to `true` to make the sorting of strings case sensitive.
/// * `by`: set to `"value"` to sort by value. Defaults to `"key"`.
/// * `reverse`: set to `true` to sort in reverse.
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn dictsort(v: Value, kwargs: Kwargs) -> Result<Value, Error> {
if v.kind() == ValueKind::Map {
let mut rv = Vec::with_capacity(v.len().unwrap_or(0));
let iter = ok!(v.try_iter());
for key in iter {
let value = v.get_item(&key).unwrap_or(Value::UNDEFINED);
rv.push((key, value));
}
let by_value = match ok!(kwargs.get("by")) {
None | Some("key") => false,
Some("value") => true,
Some(invalid) => {
return Err(Error::new(
ErrorKind::InvalidOperation,
format!("invalid value '{}' for 'by' parameter", invalid),
))
}
};
let case_sensitive = ok!(kwargs.get::<Option<bool>>("case_sensitive")).unwrap_or(false);
rv.sort_by(|a, b| {
let (a, b) = if by_value { (&a.1, &b.1) } else { (&a.0, &b.0) };
cmp_helper(a, b, case_sensitive)
});
if let Some(true) = ok!(kwargs.get("reverse")) {
rv.reverse();
}
ok!(kwargs.assert_all_used());
Ok(Value::from(
rv.into_iter()
.map(|(k, v)| Value::from(vec![k, v]))
.collect::<Vec<_>>(),
))
} else {
Err(Error::new(
ErrorKind::InvalidOperation,
"cannot convert value into pair list",
))
}
}
/// Returns a list of pairs (items) from a mapping.
///
/// This can be used to iterate over keys and values of a mapping
/// at once. Note that this will use the original order of the map
/// which is typically arbitrary unless the `preserve_order` feature
/// is used in which case the original order of the map is retained.
/// It's generally better to use `|dictsort` which sorts the map by
/// key before iterating.
///
/// ```jinja
/// <dl>
/// {% for key, value in my_dict|items %}
/// <dt>{{ key }}
/// <dd>{{ value }}
/// {% endfor %}
/// </dl>
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn items(v: Value) -> Result<Value, Error> {
if v.kind() == ValueKind::Map {
let mut rv = Vec::with_capacity(v.len().unwrap_or(0));
let iter = ok!(v.try_iter());
for key in iter {
let value = v.get_item(&key).unwrap_or(Value::UNDEFINED);
rv.push(Value::from(vec![key, value]));
}
Ok(Value::from(rv))
} else {
Err(Error::new(
ErrorKind::InvalidOperation,
"cannot convert value into pair list",
))
}
}
/// Reverses an iterable or string
///
/// ```jinja
/// {% for user in users|reverse %}
/// <li>{{ user.name }}
/// {% endfor %}
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn reverse(v: Value) -> Result<Value, Error> {
v.reverse()
}
/// Trims a value
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn trim(s: Cow<'_, str>, chars: Option<Cow<'_, str>>) -> String {
match chars {
Some(chars) => {
let chars = chars.chars().collect::<Vec<_>>();
s.trim_matches(&chars[..]).to_string()
}
None => s.trim().to_string(),
}
}
/// Joins a sequence by a character
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn join(val: Value, joiner: Option<Cow<'_, str>>) -> Result<String, Error> {
if val.is_undefined() || val.is_none() {
return Ok(String::new());
}
let joiner = joiner.as_ref().unwrap_or(&Cow::Borrowed(""));
let iter = ok!(val.try_iter().map_err(|err| {
Error::new(
ErrorKind::InvalidOperation,
format!("cannot join value of type {}", val.kind()),
)
.with_source(err)
}));
let mut rv = String::new();
for item in iter {
if !rv.is_empty() {
rv.push_str(joiner);
}
if let Some(s) = item.as_str() {
rv.push_str(s);
} else {
write!(rv, "{item}").ok();
}
}
Ok(rv)
}
/// Split a string into its substrings, using `split` as the separator string.
///
/// If `split` is not provided or `none` the string is split at all whitespace
/// characters and multiple spaces and empty strings will be removed from the
/// result.
///
/// The `maxsplits` parameter defines the maximum number of splits
/// (starting from the left). Note that this follows Python conventions
/// rather than Rust ones so `1` means one split and two resulting items.
///
/// ```jinja
/// {{ "hello world"|split|list }}
/// -> ["hello", "world"]
///
/// {{ "c,s,v"|split(",")|list }}
/// -> ["c", "s", "v"]
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn split(s: Arc<str>, split: Option<Arc<str>>, maxsplits: Option<i64>) -> Value {
let maxsplits = maxsplits.and_then(|x| if x >= 0 { Some(x as usize + 1) } else { None });
Value::make_object_iterable((s, split), move |(s, split)| match (split, maxsplits) {
(None, None) => Box::new(s.split_whitespace().map(Value::from)),
(Some(split), None) => Box::new(s.split(split as &str).map(Value::from)),
(None, Some(n)) => Box::new(splitn_whitespace(s, n).map(Value::from)),
(Some(split), Some(n)) => Box::new(s.splitn(n, split as &str).map(Value::from)),
})
}
/// Splits a string into lines.
///
/// The newline character is removed in the process and not retained. This
/// function supports both Windows and UNIX style newlines.
///
/// ```jinja
/// {{ "foo\nbar\nbaz"|lines }}
/// -> ["foo", "bar", "baz"]
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn lines(s: Arc<str>) -> Value {
Value::from_iter(s.lines().map(|x| x.to_string()))
}
/// If the value is undefined it will return the passed default value,
/// otherwise the value of the variable:
///
/// ```jinja
/// <p>{{ my_variable|default("my_variable was not defined") }}</p>
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn default(value: Value, other: Option<Value>) -> Value {
if value.is_undefined() {
other.unwrap_or_else(|| Value::from(""))
} else {
value
}
}
/// Returns the absolute value of a number.
///
/// ```jinja
/// |a - b| = {{ (a - b)|abs }}
/// -> |2 - 4| = 2
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn abs(value: Value) -> Result<Value, Error> {
match value.0 {
ValueRepr::U64(_) | ValueRepr::U128(_) => Ok(value),
ValueRepr::I64(x) => match x.checked_abs() {
Some(rv) => Ok(Value::from(rv)),
None => Ok(Value::from((x as i128).abs())), // this cannot overflow
},
ValueRepr::I128(x) => {
x.0.checked_abs()
.map(Value::from)
.ok_or_else(|| Error::new(ErrorKind::InvalidOperation, "overflow on abs"))
}
ValueRepr::F64(x) => Ok(Value::from(x.abs())),
_ => Err(Error::new(
ErrorKind::InvalidOperation,
"cannot get absolute value",
)),
}
}
/// Converts a value into an integer.
///
/// ```jinja
/// {{ "42"|int == 42 }} -> true
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn int(value: Value) -> Result<Value, Error> {
match &value.0 {
ValueRepr::Undefined | ValueRepr::None => Ok(Value::from(0)),
ValueRepr::Bool(x) => Ok(Value::from(*x as u64)),
ValueRepr::U64(_) | ValueRepr::I64(_) | ValueRepr::U128(_) | ValueRepr::I128(_) => {
Ok(value)
}
ValueRepr::F64(v) => Ok(Value::from(*v as i128)),
ValueRepr::String(..) | ValueRepr::SmallStr(_) => {
let s = value.as_str().unwrap();
if let Ok(i) = s.parse::<i128>() {
Ok(Value::from(i))
} else {
match s.parse::<f64>() {
Ok(f) => Ok(Value::from(f as i128)),
Err(err) => Err(Error::new(ErrorKind::InvalidOperation, err.to_string())),
}
}
}
ValueRepr::Bytes(_) | ValueRepr::Object(_) => Err(Error::new(
ErrorKind::InvalidOperation,
format!("cannot convert {} to integer", value.kind()),
)),
ValueRepr::Invalid(_) => value.validate(),
}
}
/// Converts a value into a float.
///
/// ```jinja
/// {{ "42.5"|float == 42.5 }} -> true
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn float(value: Value) -> Result<Value, Error> {
match &value.0 {
ValueRepr::Undefined | ValueRepr::None => Ok(Value::from(0.0)),
ValueRepr::Bool(x) => Ok(Value::from(*x as u64 as f64)),
ValueRepr::String(..) | ValueRepr::SmallStr(_) => value
.as_str()
.unwrap()
.parse::<f64>()
.map(Value::from)
.map_err(|err| Error::new(ErrorKind::InvalidOperation, err.to_string())),
ValueRepr::Invalid(_) => value.validate(),
_ => as_f64(&value, true).map(Value::from).ok_or_else(|| {
Error::new(
ErrorKind::InvalidOperation,
format!("cannot convert {} to float", value.kind()),
)
}),
}
}
/// Looks up an attribute.
///
/// In MiniJinja this is the same as the `[]` operator. In Jinja2 there is a
/// small difference which is why this filter is sometimes used in Jinja2
/// templates. For compatibility it's provided here as well.
///
/// ```jinja
/// {{ value['key'] == value|attr('key') }} -> true
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn attr(value: Value, key: &Value) -> Result<Value, Error> {
value.get_item(key)
}
/// Round the number to a given precision.
///
/// Round the number to a given precision. The first parameter specifies the
/// precision (default is 0).
///
/// ```jinja
/// {{ 42.55|round }}
/// -> 43.0
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn round(value: Value, precision: Option<i32>) -> Result<Value, Error> {
match value.0 {
ValueRepr::I64(_) | ValueRepr::I128(_) | ValueRepr::U64(_) | ValueRepr::U128(_) => {
Ok(value)
}
ValueRepr::F64(val) => {
let x = 10f64.powi(precision.unwrap_or(0));
Ok(Value::from((x * val).round() / x))
}
_ => Err(Error::new(
ErrorKind::InvalidOperation,
format!("cannot round value ({})", value.kind()),
)),
}
}
/// Returns the first item from an iterable.
///
/// If the list is empty `undefined` is returned.
///
/// ```jinja
/// <dl>
/// <dt>primary email
/// <dd>{{ user.email_addresses|first|default('no user') }}
/// </dl>
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn first(value: Value) -> Result<Value, Error> {
if let Some(s) = value.as_str() {
Ok(s.chars().next().map_or(Value::UNDEFINED, Value::from))
} else if let Some(mut iter) = value.as_object().and_then(|x| x.try_iter()) {
Ok(iter.next().unwrap_or(Value::UNDEFINED))
} else {
Err(Error::new(
ErrorKind::InvalidOperation,
"cannot get first item from value",
))
}
}
/// Returns the last item from an iterable.
///
/// If the list is empty `undefined` is returned.
///
/// ```jinja
/// <h2>Most Recent Update</h2>
/// {% with update = updates|last %}
/// <dl>
/// <dt>Location
/// <dd>{{ update.location }}
/// <dt>Status
/// <dd>{{ update.status }}
/// </dl>
/// {% endwith %}
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn last(value: Value) -> Result<Value, Error> {
if let Some(s) = value.as_str() {
Ok(s.chars().next_back().map_or(Value::UNDEFINED, Value::from))
} else if matches!(value.kind(), ValueKind::Seq | ValueKind::Iterable) {
let rev = ok!(value.reverse());
let mut iter = ok!(rev.try_iter());
Ok(iter.next().unwrap_or_default())
} else {
Err(Error::new(
ErrorKind::InvalidOperation,
"cannot get last item from value",
))
}
}
/// Returns the smallest item from an iterable.
///
/// ```jinja
/// {{ [1, 2, 3, 4]|min }} -> 1
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn min(state: &State, value: Value) -> Result<Value, Error> {
let iter = ok!(state.undefined_behavior().try_iter(value).map_err(|err| {
Error::new(ErrorKind::InvalidOperation, "cannot convert value to list").with_source(err)
}));
Ok(iter.min().unwrap_or(Value::UNDEFINED))
}
/// Returns the largest item from an iterable.
///
/// ```jinja
/// {{ [1, 2, 3, 4]|max }} -> 4
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn max(state: &State, value: Value) -> Result<Value, Error> {
let iter = ok!(state.undefined_behavior().try_iter(value).map_err(|err| {
Error::new(ErrorKind::InvalidOperation, "cannot convert value to list").with_source(err)
}));
Ok(iter.max().unwrap_or(Value::UNDEFINED))
}
/// Returns the sorted version of the given list.
///
/// The filter accepts a few keyword arguments:
///
/// * `case_sensitive`: set to `true` to make the sorting of strings case sensitive.
/// * `attribute`: can be set to an attribute or dotted path to sort by that attribute
/// * `reverse`: set to `true` to sort in reverse.
///
/// ```jinja
/// {{ [1, 3, 2, 4]|sort }} -> [4, 3, 2, 1]
/// {{ [1, 3, 2, 4]|sort(reverse=true) }} -> [1, 2, 3, 4]
/// # Sort users by age attribute in descending order.
/// {{ users|sort(attribute="age") }}
/// # Sort users by age attribute in ascending order.
/// {{ users|sort(attribute="age", reverse=true) }}
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn sort(state: &State, value: Value, kwargs: Kwargs) -> Result<Value, Error> {
let mut items = ok!(state.undefined_behavior().try_iter(value).map_err(|err| {
Error::new(ErrorKind::InvalidOperation, "cannot convert value to list").with_source(err)
}))
.collect::<Vec<_>>();
let case_sensitive = ok!(kwargs.get::<Option<bool>>("case_sensitive")).unwrap_or(false);
if let Some(attr) = ok!(kwargs.get::<Option<&str>>("attribute")) {
items.sort_by(|a, b| match (a.get_path(attr), b.get_path(attr)) {
(Ok(a), Ok(b)) => cmp_helper(&a, &b, case_sensitive),
_ => Ordering::Equal,
});
} else {
items.sort_by(|a, b| cmp_helper(a, b, case_sensitive))
}
if let Some(true) = ok!(kwargs.get("reverse")) {
items.reverse();
}
ok!(kwargs.assert_all_used());
Ok(Value::from(items))
}
/// Converts the input value into a list.
///
/// If the value is already a list, then it's returned unchanged.
/// Applied to a map this returns the list of keys, applied to a
/// string this returns the characters. If the value is undefined
/// an empty list is returned.
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn list(state: &State, value: Value) -> Result<Value, Error> {
let iter = ok!(state.undefined_behavior().try_iter(value).map_err(|err| {
Error::new(ErrorKind::InvalidOperation, "cannot convert value to list").with_source(err)
}));
Ok(Value::from(iter.collect::<Vec<_>>()))
}
/// Converts a value into a string if it's not one already.
///
/// If the string has been marked as safe, that value is preserved.
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn string(value: Value) -> Value {
if value.kind() == ValueKind::String {
value
} else {
value.to_string().into()
}
}
/// Converts the value into a boolean value.
///
/// This behaves the same as the if statement does with regards to
/// handling of boolean values.
///
/// ```jinja
/// {{ 42|bool }} -> true
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn bool(value: Value) -> bool {
value.is_true()
}
/// Slice an iterable and return a list of lists containing
/// those items.
///
/// Useful if you want to create a div containing three ul tags that
/// represent columns:
///
/// ```jinja
/// <div class="columnwrapper">
/// {% for column in items|slice(3) %}
/// <ul class="column-{{ loop.index }}">
/// {% for item in column %}
/// <li>{{ item }}</li>
/// {% endfor %}
/// </ul>
/// {% endfor %}
/// </div>
/// ```
///
/// If you pass it a second argument it’s used to fill missing values on the
/// last iteration.
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn slice(
state: &State,
value: Value,
count: usize,
fill_with: Option<Value>,
) -> Result<Value, Error> {
if count == 0 {
return Err(Error::new(ErrorKind::InvalidOperation, "count cannot be 0"));
}
let items = ok!(state.undefined_behavior().try_iter(value)).collect::<Vec<_>>();
let len = items.len();
let items_per_slice = len / count;
let slices_with_extra = len % count;
let mut offset = 0;
let mut rv = Vec::with_capacity(count);
for slice in 0..count {
let start = offset + slice * items_per_slice;
if slice < slices_with_extra {
offset += 1;
}
let end = offset + (slice + 1) * items_per_slice;
let tmp = &items[start..end];
if let Some(ref filler) = fill_with {
if slice >= slices_with_extra {
let mut tmp = tmp.to_vec();
tmp.push(filler.clone());
rv.push(Value::from(tmp));
continue;
}
}
rv.push(Value::from(tmp.to_vec()));
}
Ok(Value::from(rv))
}
/// Batch items.
///
/// This filter works pretty much like `slice` just the other way round. It
/// returns a list of lists with the given number of items. If you provide a
/// second parameter this is used to fill up missing items.
///
/// ```jinja
/// <table>
/// {% for row in items|batch(3, ' ') %}
/// <tr>
/// {% for column in row %}
/// <td>{{ column }}</td>
/// {% endfor %}
/// </tr>
/// {% endfor %}
/// </table>
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn batch(
state: &State,
value: Value,
count: usize,
fill_with: Option<Value>,
) -> Result<Value, Error> {
if count == 0 {
return Err(Error::new(ErrorKind::InvalidOperation, "count cannot be 0"));
}
let mut rv = Vec::with_capacity(value.len().unwrap_or(0) / count);
let mut tmp = Vec::with_capacity(count);
for item in ok!(state.undefined_behavior().try_iter(value)) {
if tmp.len() == count {
rv.push(Value::from(mem::replace(
&mut tmp,
Vec::with_capacity(count),
)));
}
tmp.push(item);
}
if !tmp.is_empty() {
if let Some(filler) = fill_with {
for _ in 0..count - tmp.len() {
tmp.push(filler.clone());
}
}
rv.push(Value::from(tmp));
}
Ok(Value::from(rv))
}
/// Dumps a value to JSON.
///
/// This filter is only available if the `json` feature is enabled. The resulting
/// value is safe to use in HTML as well as it will not contain any special HTML
/// characters. The optional parameter to the filter can be set to `true` to enable
/// pretty printing. Not that the `"` character is left unchanged as it's the
/// JSON string delimiter. If you want to pass JSON serialized this way into an
/// HTTP attribute use single quoted HTML attributes:
///
/// ```jinja
/// <script>
/// const GLOBAL_CONFIG = {{ global_config|tojson }};
/// </script>
/// <a href="#" data-info='{{ json_object|tojson }}'>...</a>
/// ```
///
/// The filter takes one argument `indent` (which can also be passed as keyword
/// argument for compatibility with Jinja2) which can be set to `true` to enable
/// pretty printing or an integer to control the indentation of the pretty
/// printing feature.
///
/// ```jinja
/// <script>
/// const GLOBAL_CONFIG = {{ global_config|tojson(indent=2) }};
/// </script>
/// ```
#[cfg_attr(docsrs, doc(cfg(all(feature = "builtins", feature = "json"))))]
#[cfg(feature = "json")]
pub fn tojson(value: Value, indent: Option<Value>, args: Kwargs) -> Result<Value, Error> {
let indent = match indent {
Some(indent) => Some(indent),
None => ok!(args.get("indent")),
};
let indent = match indent {
None => None,
Some(ref val) => match bool::try_from(val.clone()).ok() {
Some(true) => Some(2),
Some(false) => None,
None => Some(ok!(usize::try_from(val.clone()))),
},
};
ok!(args.assert_all_used());
if let Some(indent) = indent {
let mut out = Vec::<u8>::new();
let indentation = " ".repeat(indent);
let formatter = serde_json::ser::PrettyFormatter::with_indent(indentation.as_bytes());
let mut s = serde_json::Serializer::with_formatter(&mut out, formatter);
serde::Serialize::serialize(&value, &mut s)
.map(|_| unsafe { String::from_utf8_unchecked(out) })
} else {
serde_json::to_string(&value)
}
.map_err(|err| {
Error::new(ErrorKind::InvalidOperation, "cannot serialize to JSON").with_source(err)
})
.map(|s| {
// When this filter is used the return value is safe for both HTML and JSON
let mut rv = String::with_capacity(s.len());
for c in s.chars() {
match c {
'<' => rv.push_str("\\u003c"),
'>' => rv.push_str("\\u003e"),
'&' => rv.push_str("\\u0026"),
'\'' => rv.push_str("\\u0027"),
_ => rv.push(c),
}
}
Value::from_safe_string(rv)
})
}
/// Indents Value with spaces
///
/// The first optional parameter to the filter can be set to `true` to
/// indent the first line. The parameter defaults to false.
/// the second optional parameter to the filter can be set to `true`
/// to indent blank lines. The parameter defaults to false.
/// This filter is useful, if you want to template yaml-files
///
/// ```jinja
/// example:
/// config:
/// {{ global_conifg|indent(2) }} # does not indent first line
/// {{ global_config|indent(2,true) }} # indent whole Value with two spaces
/// {{ global_config|indent(2,true,true)}} # indent whole Value and all blank lines
/// ```
#[cfg_attr(docsrs, doc(cfg(all(feature = "builtins"))))]
pub fn indent(
mut value: String,
width: usize,
indent_first_line: Option<bool>,
indent_blank_lines: Option<bool>,
) -> String {
fn strip_trailing_newline(input: &mut String) {
if input.ends_with('\n') {
input.truncate(input.len() - 1);
}
if input.ends_with('\r') {
input.truncate(input.len() - 1);
}
}
strip_trailing_newline(&mut value);
let indent_with = " ".repeat(width);
let mut output = String::new();
let mut iterator = value.split('\n');
if !indent_first_line.unwrap_or(false) {
output.push_str(iterator.next().unwrap());
output.push('\n');
}
for line in iterator {
if line.is_empty() {
if indent_blank_lines.unwrap_or(false) {
output.push_str(&indent_with);
}
} else {
write!(output, "{}{}", indent_with, line).ok();
}
output.push('\n');
}
strip_trailing_newline(&mut output);
output
}
/// URL encodes a value.
///
/// If given a map it encodes the parameters into a query set, otherwise it
/// encodes the stringified value. If the value is none or undefined, an
/// empty string is returned.
///
/// ```jinja
/// <a href="/search?{{ {"q": "my search", "lang": "fr"}|urlencode }}">Search</a>
/// ```
#[cfg_attr(docsrs, doc(cfg(all(feature = "builtins", feature = "urlencode"))))]
#[cfg(feature = "urlencode")]
pub fn urlencode(value: Value) -> Result<String, Error> {
const SET: &percent_encoding::AsciiSet = &percent_encoding::NON_ALPHANUMERIC
.remove(b'/')
.remove(b'.')
.remove(b'-')
.remove(b'_')
.add(b' ');
if value.kind() == ValueKind::Map {
let mut rv = String::new();
for k in ok!(value.try_iter()) {
let v = ok!(value.get_item(&k));
if v.is_none() || v.is_undefined() {
continue;
}
if !rv.is_empty() {
rv.push('&');
}
write!(
rv,
"{}={}",
percent_encoding::utf8_percent_encode(&k.to_string(), SET),
percent_encoding::utf8_percent_encode(&v.to_string(), SET)
)
.unwrap();
}
Ok(rv)
} else {
match &value.0 {
ValueRepr::None | ValueRepr::Undefined => Ok("".into()),
ValueRepr::Bytes(b) => Ok(percent_encoding::percent_encode(b, SET).to_string()),
ValueRepr::String(..) | ValueRepr::SmallStr(_) => Ok(
percent_encoding::utf8_percent_encode(value.as_str().unwrap(), SET).to_string(),
),
_ => Ok(percent_encoding::utf8_percent_encode(&value.to_string(), SET).to_string()),
}
}
}
fn select_or_reject(
state: &State,
invert: bool,
value: Value,
attr: Option<Cow<'_, str>>,
test_name: Option<Cow<'_, str>>,
args: crate::value::Rest<Value>,
) -> Result<Vec<Value>, Error> {
let mut rv = vec![];
let test = if let Some(test_name) = test_name {
Some(ok!(state
.env
.get_test(&test_name)
.ok_or_else(|| Error::from(ErrorKind::UnknownTest))))
} else {
None
};
for value in ok!(state.undefined_behavior().try_iter(value)) {
let test_value = if let Some(ref attr) = attr {
ok!(value.get_path(attr))
} else {
value.clone()
};
let passed = if let Some(test) = test {
let new_args = Some(test_value)
.into_iter()
.chain(args.0.iter().cloned())
.collect::<Vec<_>>();
ok!(test.perform(state, &new_args))
} else {
test_value.is_true()
};
if passed != invert {
rv.push(value);
}
}
Ok(rv)
}
/// Creates a new sequence of values that pass a test.
///
/// Filters a sequence of objects by applying a test to each object.
/// Only values that pass the test are included.
///
/// If no test is specified, each object will be evaluated as a boolean.
///
/// ```jinja
/// {{ [1, 2, 3, 4]|select("odd") }} -> [1, 3]
/// {{ [false, null, 42]|select }} -> [42]
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn select(
state: &State,
value: Value,
test_name: Option<Cow<'_, str>>,
args: crate::value::Rest<Value>,
) -> Result<Vec<Value>, Error> {
select_or_reject(state, false, value, None, test_name, args)
}
/// Creates a new sequence of values of which an attribute passes a test.
///
/// This functions like [`select`] but it will test an attribute of the
/// object itself:
///
/// ```jinja
/// {{ users|selectattr("is_active") }} -> all users where x.is_active is true
/// {{ users|selectattr("id", "even") }} -> returns all users with an even id
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn selectattr(
state: &State,
value: Value,
attr: Cow<'_, str>,
test_name: Option<Cow<'_, str>>,
args: crate::value::Rest<Value>,
) -> Result<Vec<Value>, Error> {
select_or_reject(state, false, value, Some(attr), test_name, args)
}
/// Creates a new sequence of values that don't pass a test.
///
/// This is the inverse of [`select`].
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn reject(
state: &State,
value: Value,
test_name: Option<Cow<'_, str>>,
args: crate::value::Rest<Value>,
) -> Result<Vec<Value>, Error> {
select_or_reject(state, true, value, None, test_name, args)
}
/// Creates a new sequence of values of which an attribute does not pass a test.
///
/// This functions like [`select`] but it will test an attribute of the
/// object itself:
///
/// ```jinja
/// {{ users|rejectattr("is_active") }} -> all users where x.is_active is false
/// {{ users|rejectattr("id", "even") }} -> returns all users with an odd id
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn rejectattr(
state: &State,
value: Value,
attr: Cow<'_, str>,
test_name: Option<Cow<'_, str>>,
args: crate::value::Rest<Value>,
) -> Result<Vec<Value>, Error> {
select_or_reject(state, true, value, Some(attr), test_name, args)
}
/// Applies a filter to a sequence of objects or looks up an attribute.
///
/// This is useful when dealing with lists of objects but you are really
/// only interested in a certain value of it.
///
/// The basic usage is mapping on an attribute. Given a list of users
/// you can for instance quickly select the username and join on it:
///
/// ```jinja
/// {{ users|map(attribute='username')|join(', ') }}
/// ```
///
/// You can specify a `default` value to use if an object in the list does
/// not have the given attribute.
///
/// ```jinja
/// {{ users|map(attribute="username", default="Anonymous")|join(", ") }}
/// ```
///
/// Alternatively you can have `map` invoke a filter by passing the name of the
/// filter and the arguments afterwards. A good example would be applying a
/// text conversion filter on a sequence:
///
/// ```jinja
/// Users on this page: {{ titles|map('lower')|join(', ') }}
/// ```
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn map(
state: &State,
value: Value,
args: crate::value::Rest<Value>,
) -> Result<Vec<Value>, Error> {
let mut rv = Vec::with_capacity(value.len().unwrap_or(0));
// attribute mapping
let (args, kwargs): (&[Value], Kwargs) = crate::value::from_args(&args)?;
if let Some(attr) = ok!(kwargs.get::<Option<Value>>("attribute")) {
if !args.is_empty() {
return Err(Error::from(ErrorKind::TooManyArguments));
}
let default = if kwargs.has("default") {
ok!(kwargs.get::<Value>("default"))
} else {
Value::UNDEFINED
};
for value in ok!(state.undefined_behavior().try_iter(value)) {
let sub_val = match attr.as_str() {
Some(path) => value.get_path(path),
None => value.get_item(&attr),
};
rv.push(match (sub_val, &default) {
(Ok(attr), _) => {
if attr.is_undefined() {
default.clone()
} else {
attr
}
}
(Err(_), default) if !default.is_undefined() => default.clone(),
(Err(err), _) => return Err(err),
});
}
ok!(kwargs.assert_all_used());
return Ok(rv);
}
// filter mapping
let filter_name = ok!(args
.first()
.ok_or_else(|| Error::new(ErrorKind::InvalidOperation, "filter name is required")));
let filter_name = ok!(filter_name.as_str().ok_or_else(|| {
Error::new(ErrorKind::InvalidOperation, "filter name must be a string")
}));
let filter = ok!(state
.env
.get_filter(filter_name)
.ok_or_else(|| Error::from(ErrorKind::UnknownFilter)));
for value in ok!(state.undefined_behavior().try_iter(value)) {
let new_args = Some(value.clone())
.into_iter()
.chain(args.iter().skip(1).cloned())
.collect::<Vec<_>>();
rv.push(ok!(filter.apply_to(state, &new_args)));
}
Ok(rv)
}
/// Group a sequence of objects by an attribute.
///
/// The attribute can use dot notation for nested access, like `"address.city"``.
/// The values are sorted first so only one group is returned for each unique value.
/// The attribute can be passed as first argument or as keyword argument named
/// `attribute`.
///
/// For example, a list of User objects with a city attribute can be
/// rendered in groups. In this example, grouper refers to the city value of
/// the group.
///
/// ```jinja
/// <ul>{% for city, items in users|groupby("city") %}
/// <li>{{ city }}
/// <ul>{% for user in items %}
/// <li>{{ user.name }}
/// {% endfor %}</ul>
/// </li>
/// {% endfor %}</ul>
/// ```
///
/// groupby yields named tuples of `(grouper, list)``, which can be used instead
/// of the tuple unpacking above. As such this example is equivalent:
///
/// ```jinja
/// <ul>{% for group in users|groupby(attribute="city") %}
/// <li>{{ group.grouper }}
/// <ul>{% for user in group.list %}
/// <li>{{ user.name }}
/// {% endfor %}</ul>
/// </li>
/// {% endfor %}</ul>
/// ```
///
/// You can specify a default value to use if an object in the list does not
/// have the given attribute.
///
/// ```jinja
/// <ul>{% for city, items in users|groupby("city", default="NY") %}
/// <li>{{ city }}: {{ items|map(attribute="name")|join(", ") }}</li>
/// {% endfor %}</ul>
/// ```
///
/// Like the [`sort`] filter, sorting and grouping is case-insensitive by default.
/// The key for each group will have the case of the first item in that group
/// of values. For example, if a list of users has cities `["CA", "NY", "ca"]``,
/// the "CA" group will have two values. This can be disabled by passing
/// `case_sensitive=True`.
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn groupby(value: Value, attribute: Option<&str>, kwargs: Kwargs) -> Result<Value, Error> {
let default = ok!(kwargs.get::<Option<Value>>("default")).unwrap_or_default();
let case_sensitive = ok!(kwargs.get::<Option<bool>>("case_sensitive")).unwrap_or(false);
let attr = match attribute {
Some(attr) => attr,
None => ok!(kwargs.get::<&str>("attribute")),
};
let mut items: Vec<Value> = ok!(value.try_iter()).collect();
items.sort_by(|a, b| {
let a = a.get_path_or_default(attr, &default);
let b = b.get_path_or_default(attr, &default);
cmp_helper(&a, &b, case_sensitive)
});
ok!(kwargs.assert_all_used());
#[derive(Debug)]
pub struct GroupTuple {
grouper: Value,
list: Vec<Value>,
}
impl Object for GroupTuple {
fn repr(self: &Arc<Self>) -> ObjectRepr {
ObjectRepr::Seq
}
fn get_value(self: &Arc<Self>, key: &Value) -> Option<Value> {
match (key.as_usize(), key.as_str()) {
(Some(0), None) | (None, Some("grouper")) => Some(self.grouper.clone()),
(Some(1), None) | (None, Some("list")) => {
Some(Value::make_object_iterable(self.clone(), |this| {
Box::new(this.list.iter().cloned())
as Box<dyn Iterator<Item = _> + Send + Sync>
}))
}
_ => None,
}
}
fn enumerate(self: &Arc<Self>) -> Enumerator {
Enumerator::Seq(2)
}
}
let mut rv = Vec::new();
let mut grouper = None::<Value>;
let mut list = Vec::new();
for item in items {
let group_by = item.get_path_or_default(attr, &default);
if let Some(ref last_grouper) = grouper {
if cmp_helper(last_grouper, &group_by, case_sensitive) != Ordering::Equal {
rv.push(Value::from_object(GroupTuple {
grouper: last_grouper.clone(),
list: std::mem::take(&mut list),
}));
}
}
grouper = Some(group_by);
list.push(item);
}
if !list.is_empty() {
rv.push(Value::from_object(GroupTuple {
grouper: grouper.unwrap(),
list,
}));
}
Ok(Value::from_object(rv))
}
/// Returns a list of unique items from the given iterable.
///
/// ```jinja
/// {{ ['foo', 'bar', 'foobar', 'foobar']|unique|list }}
/// -> ['foo', 'bar', 'foobar']
/// ```
///
/// The unique items are yielded in the same order as their first occurrence
/// in the iterable passed to the filter. The filter will not detect
/// duplicate objects or arrays, only primitives such as strings or numbers.
///
/// Optionally the `attribute` keyword argument can be used to make the filter
/// operate on an attribute instead of the value itself. In this case only
/// one city per state would be returned:
///
/// ```jinja
/// {{ list_of_cities|unique(attribute='state') }}
/// ```
///
/// Like the [`sort`] filter this operates case-insensitive by default.
/// For example, if a list has the US state codes `["CA", "NY", "ca"]``,
/// the resulting list will have `["CA", "NY"]`. This can be disabled by
/// passing `case_sensitive=True`.
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn unique(values: Vec<Value>, kwargs: Kwargs) -> Result<Value, Error> {
use std::collections::BTreeSet;
let attr = ok!(kwargs.get::<Option<&str>>("attribute"));
let case_sensitive = ok!(kwargs.get::<Option<bool>>("case_sensitive")).unwrap_or(false);
ok!(kwargs.assert_all_used());
let mut rv = Vec::new();
let mut seen = BTreeSet::new();
for item in values {
let value_to_compare = if let Some(attr) = attr {
item.get_path_or_default(attr, &Value::UNDEFINED)
} else {
item.clone()
};
let memorized_value = if case_sensitive {
value_to_compare.clone()
} else if let Some(s) = value_to_compare.as_str() {
Value::from(s.to_lowercase())
} else {
value_to_compare.clone()
};
if !seen.contains(&memorized_value) {
rv.push(item);
seen.insert(memorized_value);
}
}
Ok(Value::from(rv))
}
/// Pretty print a variable.
///
/// This is useful for debugging as it better shows what's inside an object.
#[cfg_attr(docsrs, doc(cfg(feature = "builtins")))]
pub fn pprint(value: &Value) -> String {
format!("{:#?}", value)
}
}
#[cfg(feature = "builtins")]
pub use self::builtins::*;