leo_passes/destructuring/
destructure_expression.rs

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// Copyright (C) 2019-2025 Provable Inc.
// This file is part of the Leo library.

// The Leo library is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// The Leo library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with the Leo library. If not, see <https://www.gnu.org/licenses/>.

use crate::Destructurer;

use leo_ast::{
    AccessExpression,
    ArrayAccess,
    Expression,
    ExpressionReconstructor,
    IntegerType,
    Literal,
    Statement,
    TupleAccess,
    Type,
};

impl ExpressionReconstructor for Destructurer<'_> {
    type AdditionalOutput = Vec<Statement>;

    /// Replaces a tuple access expression with the appropriate expression.
    fn reconstruct_tuple_access(&mut self, input: TupleAccess) -> (Expression, Self::AdditionalOutput) {
        // Lookup the expression in the tuple map.
        match input.tuple.as_ref() {
            Expression::Identifier(identifier) => {
                match self.tuples.get(&identifier.name).and_then(|tuple| tuple.elements.get(input.index.value())) {
                    Some(element) => (element.clone(), Default::default()),
                    None => {
                        if matches!(self.type_table.get(&identifier.id), Some(Type::Future(_))) {
                            (
                                Expression::Access(AccessExpression::Array(ArrayAccess {
                                    array: Box::new(Expression::Identifier(*identifier)),
                                    index: Box::new(Expression::Literal(Literal::Integer(
                                        IntegerType::U32,
                                        input.index.to_string(),
                                        input.span,
                                        Default::default(),
                                    ))),
                                    span: input.span,
                                    id: input.id,
                                })),
                                Default::default(),
                            )
                        } else {
                            unreachable!("SSA guarantees that all tuple accesses are declared and indices are valid.")
                        }
                    }
                }
            }
            _ => unreachable!("SSA guarantees that subexpressions are identifiers or literals."),
        }
    }
}