typst/src/eval/methods.rs
Sébastien d'Herbais de Thun 1198e0cd38
Selector rework (#640)
2023-04-12 12:47:51 +02:00

345 lines
12 KiB
Rust

//! Methods on values.
use ecow::EcoString;
use super::{Args, Str, Value, Vm};
use crate::diag::{At, SourceResult};
use crate::model::{Location, Selector};
use crate::syntax::Span;
/// Call a method on a value.
pub fn call(
vm: &mut Vm,
value: Value,
method: &str,
mut args: Args,
span: Span,
) -> SourceResult<Value> {
let name = value.type_name();
let missing = || Err(missing_method(name, method)).at(span);
let output = match value {
Value::Color(color) => match method {
"lighten" => Value::Color(color.lighten(args.expect("amount")?)),
"darken" => Value::Color(color.darken(args.expect("amount")?)),
"negate" => Value::Color(color.negate()),
_ => return missing(),
},
Value::Str(string) => match method {
"len" => Value::Int(string.len()),
"first" => Value::Str(string.first().at(span)?),
"last" => Value::Str(string.last().at(span)?),
"at" => Value::Str(string.at(args.expect("index")?).at(span)?),
"slice" => {
let start = args.expect("start")?;
let mut end = args.eat()?;
if end.is_none() {
end = args.named("count")?.map(|c: i64| start + c);
}
Value::Str(string.slice(start, end).at(span)?)
}
"clusters" => Value::Array(string.clusters()),
"codepoints" => Value::Array(string.codepoints()),
"contains" => Value::Bool(string.contains(args.expect("pattern")?)),
"starts-with" => Value::Bool(string.starts_with(args.expect("pattern")?)),
"ends-with" => Value::Bool(string.ends_with(args.expect("pattern")?)),
"find" => {
string.find(args.expect("pattern")?).map_or(Value::None, Value::Str)
}
"position" => string
.position(args.expect("pattern")?)
.map_or(Value::None, Value::Int),
"match" => string
.match_(args.expect("pattern")?)
.map_or(Value::None, Value::Dict),
"matches" => Value::Array(string.matches(args.expect("pattern")?)),
"replace" => {
let pattern = args.expect("pattern")?;
let with = args.expect("replacement string")?;
let count = args.named("count")?;
Value::Str(string.replace(pattern, with, count))
}
"trim" => {
let pattern = args.eat()?;
let at = args.named("at")?;
let repeat = args.named("repeat")?.unwrap_or(true);
Value::Str(string.trim(pattern, at, repeat))
}
"split" => Value::Array(string.split(args.eat()?)),
_ => return missing(),
},
Value::Content(content) => match method {
"func" => content.func().into(),
"has" => Value::Bool(content.has(&args.expect::<EcoString>("field")?)),
"at" => content.at(&args.expect::<EcoString>("field")?).at(span)?,
"location" => content
.location()
.ok_or("this method can only be called on content returned by query(..)")
.at(span)?
.into(),
_ => return missing(),
},
Value::Array(array) => match method {
"len" => Value::Int(array.len()),
"first" => array.first().at(span)?.clone(),
"last" => array.last().at(span)?.clone(),
"at" => array.at(args.expect("index")?).at(span)?.clone(),
"slice" => {
let start = args.expect("start")?;
let mut end = args.eat()?;
if end.is_none() {
end = args.named("count")?.map(|c: i64| start + c);
}
Value::Array(array.slice(start, end).at(span)?)
}
"contains" => Value::Bool(array.contains(&args.expect("value")?)),
"find" => array.find(vm, args.expect("function")?)?.unwrap_or(Value::None),
"position" => array
.position(vm, args.expect("function")?)?
.map_or(Value::None, Value::Int),
"filter" => Value::Array(array.filter(vm, args.expect("function")?)?),
"map" => Value::Array(array.map(vm, args.expect("function")?)?),
"fold" => {
array.fold(vm, args.expect("initial value")?, args.expect("function")?)?
}
"any" => Value::Bool(array.any(vm, args.expect("function")?)?),
"all" => Value::Bool(array.all(vm, args.expect("function")?)?),
"flatten" => Value::Array(array.flatten()),
"rev" => Value::Array(array.rev()),
"split" => Value::Array(array.split(args.expect("separator")?)),
"join" => {
let sep = args.eat()?;
let last = args.named("last")?;
array.join(sep, last).at(span)?
}
"sorted" => Value::Array(array.sorted(vm, span, args.named("key")?)?),
"enumerate" => Value::Array(array.enumerate()),
_ => return missing(),
},
Value::Dict(dict) => match method {
"len" => Value::Int(dict.len()),
"at" => dict.at(&args.expect::<Str>("key")?).at(span)?.clone(),
"keys" => Value::Array(dict.keys()),
"values" => Value::Array(dict.values()),
"pairs" => Value::Array(dict.pairs()),
_ => return missing(),
},
Value::Func(func) => match method {
"with" => Value::Func(func.with(args.take())),
"where" => {
let fields = args.to_named();
args.items.retain(|arg| arg.name.is_none());
Value::dynamic(
func.element()
.ok_or("`where()` can only be called on element functions")
.at(span)?
.where_(fields),
)
}
_ => return missing(),
},
Value::Args(args) => match method {
"pos" => Value::Array(args.to_pos()),
"named" => Value::Dict(args.to_named()),
_ => return missing(),
},
Value::Dyn(dynamic) => {
if let Some(location) = dynamic.downcast::<Location>() {
match method {
"page" => vm.vt.introspector.page(*location).into(),
"position" => vm.vt.introspector.position(*location).into(),
"page-numbering" => vm.vt.introspector.page_numbering(*location),
_ => return missing(),
}
} else if let Some(selector) = dynamic.downcast::<Selector>() {
match method {
"or" => selector.clone().or(args.all::<Selector>()?).into(),
"and" => selector.clone().and(args.all::<Selector>()?).into(),
"before" => {
let location = args.expect::<Selector>("selector")?;
let inclusive =
args.named_or_find::<bool>("inclusive")?.unwrap_or(true);
selector.clone().before(location, inclusive).into()
}
"after" => {
let location = args.expect::<Selector>("selector")?;
let inclusive =
args.named_or_find::<bool>("inclusive")?.unwrap_or(true);
selector.clone().after(location, inclusive).into()
}
_ => return missing(),
}
} else {
return (vm.items.library_method)(vm, &dynamic, method, args, span);
}
}
_ => return missing(),
};
args.finish()?;
Ok(output)
}
/// Call a mutating method on a value.
pub fn call_mut(
value: &mut Value,
method: &str,
mut args: Args,
span: Span,
) -> SourceResult<Value> {
let name = value.type_name();
let missing = || Err(missing_method(name, method)).at(span);
let mut output = Value::None;
match value {
Value::Array(array) => match method {
"push" => array.push(args.expect("value")?),
"pop" => output = array.pop().at(span)?,
"insert" => {
array.insert(args.expect("index")?, args.expect("value")?).at(span)?
}
"remove" => output = array.remove(args.expect("index")?).at(span)?,
_ => return missing(),
},
Value::Dict(dict) => match method {
"insert" => dict.insert(args.expect::<Str>("key")?, args.expect("value")?),
"remove" => {
output = dict.remove(&args.expect::<EcoString>("key")?).at(span)?
}
_ => return missing(),
},
_ => return missing(),
}
args.finish()?;
Ok(output)
}
/// Call an accessor method on a value.
pub fn call_access<'a>(
value: &'a mut Value,
method: &str,
mut args: Args,
span: Span,
) -> SourceResult<&'a mut Value> {
let name = value.type_name();
let missing = || Err(missing_method(name, method)).at(span);
let slot = match value {
Value::Array(array) => match method {
"first" => array.first_mut().at(span)?,
"last" => array.last_mut().at(span)?,
"at" => array.at_mut(args.expect("index")?).at(span)?,
_ => return missing(),
},
Value::Dict(dict) => match method {
"at" => dict.at_mut(&args.expect::<Str>("key")?).at(span)?,
_ => return missing(),
},
_ => return missing(),
};
args.finish()?;
Ok(slot)
}
/// Whether a specific method is mutating.
pub fn is_mutating(method: &str) -> bool {
matches!(method, "push" | "pop" | "insert" | "remove")
}
/// Whether a specific method is an accessor.
pub fn is_accessor(method: &str) -> bool {
matches!(method, "first" | "last" | "at")
}
/// The missing method error message.
#[cold]
fn missing_method(type_name: &str, method: &str) -> String {
format!("type {type_name} has no method `{method}`")
}
/// List the available methods for a type and whether they take arguments.
pub fn methods_on(type_name: &str) -> &[(&'static str, bool)] {
match type_name {
"color" => &[("lighten", true), ("darken", true), ("negate", false)],
"string" => &[
("len", false),
("at", true),
("clusters", false),
("codepoints", false),
("contains", true),
("ends-with", true),
("find", true),
("first", false),
("last", false),
("match", true),
("matches", true),
("position", true),
("replace", true),
("slice", true),
("split", true),
("starts-with", true),
("trim", true),
],
"content" => &[("func", false), ("has", true), ("at", true), ("location", false)],
"array" => &[
("all", true),
("any", true),
("at", true),
("contains", true),
("filter", true),
("find", true),
("first", false),
("flatten", false),
("fold", true),
("insert", true),
("split", true),
("join", true),
("last", false),
("len", false),
("map", true),
("pop", false),
("position", true),
("push", true),
("remove", true),
("rev", false),
("slice", true),
("sorted", false),
("enumerate", false),
],
"dictionary" => &[
("at", true),
("insert", true),
("keys", false),
("len", false),
("pairs", false),
("remove", true),
("values", false),
],
"function" => &[("where", true), ("with", true)],
"arguments" => &[("named", false), ("pos", false)],
"location" => &[("page", false), ("position", false), ("page-numbering", false)],
"selector" => &[("or", true), ("and", true), ("before", true), ("after", true)],
"counter" => &[
("display", true),
("at", true),
("final", true),
("step", true),
("update", true),
],
"state" => &[("display", true), ("at", true), ("final", true), ("update", true)],
_ => &[],
}
}