104 lines
3.1 KiB
Rust
104 lines
3.1 KiB
Rust
use serde::{Deserialize, Serialize};
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use tree_sitter::Node;
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use crate::{AbstractTree, Error, Expression, List, Map, Result, Value};
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#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
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pub struct Index {
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collection: Expression,
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index: Expression,
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index_end: Option<Expression>,
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}
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impl AbstractTree for Index {
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fn from_syntax_node(source: &str, node: Node) -> Result<Self> {
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let collection_node = node.child(0).unwrap();
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let collection = Expression::from_syntax_node(source, collection_node)?;
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let index_node = node.child(2).unwrap();
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let index = Expression::from_syntax_node(source, index_node)?;
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let index_end_node = node.child(4);
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let index_end = if let Some(index_end_node) = index_end_node {
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Some(Expression::from_syntax_node(source, index_end_node)?)
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} else {
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None
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};
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Ok(Index {
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collection,
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index,
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index_end,
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})
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}
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fn run(&self, source: &str, context: &mut Map) -> Result<Value> {
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let value = self.collection.run(source, context)?;
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match value {
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Value::List(list) => {
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let index = self.index.run(source, context)?.as_integer()? as usize;
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let item = if let Some(index_end) = &self.index_end {
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let index_end = index_end.run(source, context)?.as_integer()? as usize;
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let sublist = list.items()[index..=index_end].to_vec();
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Value::List(List::with_items(sublist))
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} else {
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list.items().get(index).cloned().unwrap_or_default()
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};
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Ok(item)
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}
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Value::Map(mut map) => {
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let value = if let Expression::Identifier(identifier) = &self.index {
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let key = identifier.inner();
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map.variables()?.get(key).cloned().unwrap_or(Value::Empty)
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} else {
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let value = self.index.run(source, &mut map)?;
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let key = value.as_string()?;
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map.variables()?.get(key).cloned().unwrap_or(Value::Empty)
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};
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Ok(value)
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}
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Value::String(string) => {
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let index = self.index.run(source, context)?.as_integer()? as usize;
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let item = string.chars().nth(index).unwrap_or_default();
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Ok(Value::String(item.to_string()))
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}
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_ => Err(Error::ExpectedCollection { actual: value }),
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}
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}
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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use crate::evaluate;
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#[test]
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fn evaluate_list_index() {
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let test = evaluate("x = [1 [2] 3] x:1:0").unwrap();
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assert_eq!(Value::Integer(2), test);
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}
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#[test]
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fn evaluate_map_index() {
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let test = evaluate("x = {y = {z = 2}} x:y:z").unwrap();
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assert_eq!(Value::Integer(2), test);
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}
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#[test]
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fn evaluate_complex_index() {
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let test = evaluate("x = [1 2 3]; y = || => {0}; x:((y));").unwrap();
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assert_eq!(Value::Integer(1), test);
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}
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}
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