cairo-lang-lowering 2.21.0

Cairo lowering phase.
Documentation 
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//! > simple closure.

//! > test_runner_name
test_function_lowering(expect_diagnostics: false)

//! > cairo_code
#[target_function]
fn foo(a: felt252) -> felt252 {
    let c = |a| {
        a + 3
    };
    c(2)
}

//! > semantic_diagnostics

//! > lowering_diagnostics

//! > lowering_flat
Parameters: v0: core::felt252
blk0 (root):
Statements:
  (v1: core::felt252) <- 5
End:
  Return(v1)

//! > ==========================================================================

//! > using captured copiable variable.

//! > test_runner_name
test_function_lowering(expect_diagnostics: false)

//! > cairo_code
#[target_function]
fn foo() -> felt252 {
    let x = 8;
    let c = |a| {
        x * (a + 3)
    };
    let y = c(2);
    y + x
}

//! > semantic_diagnostics

//! > lowering_diagnostics

//! > lowering_flat
Parameters:
blk0 (root):
Statements:
  (v0: core::felt252) <- 48
End:
  Return(v0)

//! > ==========================================================================

//! > Test closure desnapping a snapshot-only captured non-Copy variable (captured by value).

//! > test_runner_name
test_function_lowering

//! > cairo_code
#[target_function]
fn foo(a: Array<felt252>) -> Array<felt252> {
    let f = || *(@a);
    f()
}

//! > semantic_diagnostics

//! > lowering_diagnostics
error[E3003]: Cannot desnap a non copyable type.
 --> lib.cairo:3:16
    let f = || *(@a);
               ^^^^^
note: Trait has no implementation in context: Copy::<Array::<felt252>>.

//! > lowering_flat
<Failed lowering function - run with RUST_LOG=warn (or less) to see diagnostics>

//! > ==========================================================================

//! > Test closure that both snapshots and desnaps the same non-Copy captured variable.

//! > test_runner_name
test_function_lowering

//! > cairo_code
fn use_snap(a: @Array<felt252>) {}
#[target_function]
fn foo(a: Array<felt252>) -> Array<felt252> {
    let f = || {
        use_snap(@a);
        *(@a)
    };
    f()
}

//! > semantic_diagnostics

//! > lowering_diagnostics
error[E3003]: Cannot desnap a non copyable type.
 --> lib.cairo:6:9
        *(@a)
        ^^^^^
note: Trait has no implementation in context: Copy::<Array::<felt252>>.

//! > lowering_flat
<Failed lowering function - run with RUST_LOG=warn (or less) to see diagnostics>