dfir_lang/graph/ops/
zip_longest.rs

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1use quote::quote_spanned;
2use syn::parse_quote;
3
4use super::{
5    DelayType, OpInstGenerics, OperatorCategory, OperatorConstraints, OperatorInstance,
6    OperatorWriteOutput, Persistence, WriteContextArgs, RANGE_0, RANGE_1,
7};
8use crate::diagnostic::{Diagnostic, Level};
9
10/// > 2 input streams of type `V1` and `V2`, 1 output stream of type `itertools::EitherOrBoth<V1, V2>`
11///
12/// Zips the streams together, forming paired tuples of the inputs. Note that zipping is done
13/// per-tick. Excess items are returned as `EitherOrBoth::Left(V1)` or `EitherOrBoth::Right(V2)`.
14/// If you intead want to discard the excess, use [`zip`](#zip) instead.
15///
16/// ```dfir
17/// source_iter(0..2) -> [0]my_zip_longest;
18/// source_iter(0..3) -> [1]my_zip_longest;
19/// my_zip_longest = zip_longest()
20///     -> assert_eq([
21///         itertools::EitherOrBoth::Both(0, 0),
22///         itertools::EitherOrBoth::Both(1, 1),
23///         itertools::EitherOrBoth::Right(2)]);
24/// ```
25pub const ZIP_LONGEST: OperatorConstraints = OperatorConstraints {
26    name: "zip_longest",
27    categories: &[OperatorCategory::MultiIn],
28    hard_range_inn: &(2..=2),
29    soft_range_inn: &(2..=2),
30    hard_range_out: RANGE_1,
31    soft_range_out: RANGE_1,
32    num_args: 0,
33    persistence_args: &(0..=1),
34    type_args: RANGE_0,
35    is_external_input: false,
36    has_singleton_output: false,
37    flo_type: None,
38    ports_inn: Some(|| super::PortListSpec::Fixed(parse_quote! { 0, 1 })),
39    ports_out: None,
40    input_delaytype_fn: |_| Some(DelayType::Stratum),
41    write_fn: |&WriteContextArgs {
42                   root,
43                   op_span,
44                   ident,
45                   is_pull,
46                   inputs,
47                   op_name,
48                   op_inst:
49                       OperatorInstance {
50                           generics:
51                               OpInstGenerics {
52                                   persistence_args, ..
53                               },
54                           ..
55                       },
56                   ..
57               },
58               diagnostics| {
59        assert!(is_pull);
60
61        let persistence = match persistence_args[..] {
62            [] => Persistence::Tick,
63            [a] => a,
64            _ => unreachable!(),
65        };
66        if Persistence::Tick != persistence {
67            diagnostics.push(Diagnostic::spanned(
68                op_span,
69                Level::Error,
70                format!("`{}()` can only have `'tick` persistence.", op_name),
71            ));
72            // Fall-thru to still generate code.
73        }
74
75        let lhs = &inputs[0];
76        let rhs = &inputs[1];
77        let write_iterator = quote_spanned! {op_span=>
78            let #ident = #root::itertools::Itertools::zip_longest(#lhs, #rhs);
79        };
80
81        Ok(OperatorWriteOutput {
82            write_iterator,
83            ..Default::default()
84        })
85    },
86};
dfir_lang/graph/ops/zip_longest.rs

dfir_lang/graph/ops/
zip_longest.rs
