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dust/src/abstract_tree/identifier.rs

58 lines
1.6 KiB
Rust

use serde::{Deserialize, Serialize};
use tree_sitter::Node;
use crate::{AbstractTree, Error, Map, Result, Type, Value, BUILT_IN_FUNCTIONS};
/// A string by which a variable is known to a context.
///
/// Every variable is a key-value pair. An identifier holds the key part of that
/// pair. Its inner value can be used to retrieve a Value instance from a Map.
#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
pub struct Identifier(String);
impl Identifier {
pub fn new(inner: String) -> Self {
Identifier(inner)
}
pub fn take_inner(self) -> String {
self.0
}
pub fn inner(&self) -> &String {
&self.0
}
}
impl AbstractTree for Identifier {
fn from_syntax_node(source: &str, node: Node, _context: &Map) -> Result<Self> {
Error::expect_syntax_node(source, "identifier", node)?;
let text = &source[node.byte_range()];
Ok(Identifier(text.to_string()))
}
fn run(&self, _source: &str, context: &Map) -> Result<Value> {
if let Some(value) = context.variables()?.get(&self.0) {
Ok(value.clone())
} else {
Err(Error::VariableIdentifierNotFound(self.inner().clone()))
}
}
fn expected_type(&self, context: &Map) -> Result<Type> {
if let Some(value) = context.variables()?.get(&self.0) {
value.r#type(context)
} else {
for built_in_function in BUILT_IN_FUNCTIONS {
if self.0 == built_in_function.name() {
return Ok(built_in_function.r#type());
}
}
Ok(Type::Any)
}
}
}