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dust/src/abstract_tree/identifier.rs

78 lines
2.0 KiB
Rust

use std::fmt::{self, Display, Formatter};
use serde::{Deserialize, Serialize};
use crate::{
error::{RuntimeError, SyntaxError, ValidationError},
AbstractTree, Context, Format, SyntaxNode, Type, Value,
};
/// 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, Hash)]
pub struct Identifier(String);
impl Identifier {
pub fn new<T: Into<String>>(inner: T) -> Self {
Identifier(inner.into())
}
pub fn take_inner(self) -> String {
self.0
}
pub fn inner(&self) -> &String {
&self.0
}
}
impl AbstractTree for Identifier {
fn from_syntax(
node: SyntaxNode,
source: &str,
_context: &Context,
) -> Result<Self, SyntaxError> {
SyntaxError::expect_syntax_node(source, "identifier", node)?;
let text = &source[node.byte_range()];
debug_assert!(!text.is_empty());
Ok(Identifier(text.to_string()))
}
fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
Ok(())
}
fn expected_type(&self, context: &Context) -> Result<Type, ValidationError> {
if let Some(r#type) = context.get_type(&self.0)? {
Ok(r#type)
} else {
Err(ValidationError::VariableIdentifierNotFound(self.clone()))
}
}
fn run(&self, _source: &str, context: &Context) -> Result<Value, RuntimeError> {
if let Some(value) = context.get_value(&self.0)? {
Ok(value.clone())
} else {
Err(RuntimeError::VariableIdentifierNotFound(self.0.clone()))
}
}
}
impl Format for Identifier {
fn format(&self, output: &mut String, _indent_level: u8) {
output.push_str(&self.0);
}
}
impl Display for Identifier {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
write!(f, "{}", self.0)
}
}