dfir_lang/graph/ops/
zip.rs

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1use quote::quote_spanned;
2use syn::parse_quote;
3
4use super::{
5    OpInstGenerics, OperatorCategory, OperatorConstraints, OperatorInstance, OperatorWriteOutput,
6    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 `(V1, V2)`
11///
12/// Zips the streams together, forming paired tuples of the inputs. Note that zipping is done
13/// per-tick. Excess items from one input or the other will be discarded. If you do not want to
14/// discard the excess, use [`zip_longest`](#zip_longest) instead.
15///
16/// ```dfir
17/// source_iter(0..3) -> [0]my_zip;
18/// source_iter(0..5) -> [1]my_zip;
19/// my_zip = zip() -> assert_eq([(0, 0), (1, 1), (2, 2)]);
20/// ```
21pub const ZIP: OperatorConstraints = OperatorConstraints {
22    name: "zip",
23    categories: &[OperatorCategory::MultiIn],
24    hard_range_inn: &(2..=2),
25    soft_range_inn: &(2..=2),
26    hard_range_out: RANGE_1,
27    soft_range_out: RANGE_1,
28    num_args: 0,
29    persistence_args: &(0..=1),
30    type_args: RANGE_0,
31    is_external_input: false,
32    has_singleton_output: false,
33    flo_type: None,
34    ports_inn: Some(|| super::PortListSpec::Fixed(parse_quote! { 0, 1 })),
35    ports_out: None,
36    input_delaytype_fn: |_| None,
37    write_fn: |wc @ &WriteContextArgs {
38                   root,
39                   context,
40                   df_ident,
41                   op_span,
42                   ident,
43                   is_pull,
44                   inputs,
45                   op_name,
46                   op_inst:
47                       OperatorInstance {
48                           generics:
49                               OpInstGenerics {
50                                   persistence_args, ..
51                               },
52                           ..
53                       },
54                   ..
55               },
56               diagnostics| {
57        assert!(is_pull);
58
59        let persistence = match persistence_args[..] {
60            [] => Persistence::Tick,
61            [a] => a,
62            _ => unreachable!(),
63        };
64        if Persistence::Tick != persistence {
65            diagnostics.push(Diagnostic::spanned(
66                op_span,
67                Level::Error,
68                format!("`{}()` can only have `'tick` persistence.", op_name),
69            ));
70            // Fall-thru to still generate code.
71        }
72
73        let zipbuf_ident = wc.make_ident("zipbuf");
74
75        let write_prologue = quote_spanned! {op_span=>
76            let #zipbuf_ident = #df_ident.add_state(::std::cell::RefCell::new(
77                #root::util::monotonic_map::MonotonicMap::<
78                    #root::scheduled::ticks::TickInstant,
79                    (::std::vec::Vec<_>, ::std::vec::Vec<_>),
80                >::default()
81            ));
82        };
83
84        let lhs = &inputs[0];
85        let rhs = &inputs[1];
86        let write_iterator = quote_spanned! {op_span=>
87            let #ident = {
88                // TODO(mingwei): performance issue - get_mut_default and std::mem::take reset the vecs, reallocs heap.
89                let mut zipbuf_borrow = unsafe {
90                    // SAFETY: handle from `#df_ident.add_state(..)`.
91                    #context.state_ref_unchecked(#zipbuf_ident)
92                }.borrow_mut();
93                let (lhs_buf, rhs_buf) = zipbuf_borrow.get_mut_default(#context.current_tick());
94                #root::itertools::Itertools::zip_longest(
95                    ::std::mem::take(lhs_buf).into_iter().chain(#lhs),
96                    ::std::mem::take(rhs_buf).into_iter().chain(#rhs),
97                )
98                    .filter_map(|either| {
99                        if let #root::itertools::EitherOrBoth::Both(lhs, rhs) = either {
100                            Some((lhs, rhs))
101                        } else {
102                            let mut zipbuf_burrow = unsafe {
103                                // SAFETY: handle from `#df_ident.add_state(..)`.
104                                #context.state_ref_unchecked(#zipbuf_ident)
105                            }.borrow_mut();
106                            let (lhs_buf, rhs_buf) = zipbuf_burrow.get_mut_default(#context.current_tick());
107                            match either {
108                                #root::itertools::EitherOrBoth::Left(lhs) => lhs_buf.push(lhs),
109                                #root::itertools::EitherOrBoth::Right(rhs) => rhs_buf.push(rhs),
110                                _ => ::std::unreachable!(),
111                            }
112                            None
113                        }
114                    })
115            };
116        };
117
118        Ok(OperatorWriteOutput {
119            write_prologue,
120            write_iterator,
121            ..Default::default()
122        })
123    },
124};
dfir_lang/graph/ops/zip.rs

dfir_lang/graph/ops/
zip.rs
