46 lines
1.4 KiB
Rust
46 lines
1.4 KiB
Rust
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//! Top-level unit of Dust code.
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use tree_sitter::Node;
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use crate::{AbstractTree, Error, Result, Statement, Value, VariableMap};
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/// An abstractiton of an independent unit of source code, or a comment.
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///
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/// Items are either comments, which do nothing, or statements, which can be run
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/// to produce a single value or interact with a context by creating or
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/// referencing variables.
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#[derive(Debug)]
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pub enum Item {
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Comment(String),
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Statement(Statement),
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}
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impl AbstractTree for Item {
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fn from_syntax_node(node: Node, source: &str) -> Result<Self> {
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let child = node.child(0).unwrap();
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if child.kind() == "comment" {
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let byte_range = child.byte_range();
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let comment_text = &source[byte_range];
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Ok(Item::Comment(comment_text.to_string()))
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} else if child.kind() == "statement" {
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Ok(Item::Statement(Statement::from_syntax_node(child, source)?))
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} else {
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Err(Error::UnexpectedSyntax {
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expected: "comment or statement",
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actual: child.kind(),
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location: child.start_position(),
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relevant_source: source[node.byte_range()].to_string(),
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})
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}
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}
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fn run(&self, context: &mut VariableMap) -> Result<Value> {
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match self {
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Item::Comment(text) => Ok(Value::String(text.clone())),
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Item::Statement(statement) => statement.run(context),
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}
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}
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}
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