1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150

use crate::{CallPath, Literal, TypeInfo};

use sway_types::{ident::Ident, span::Span};

/// A [Scrutinee] is on the left-hand-side of a pattern, and dictates whether or
/// not a pattern will succeed at pattern matching and what, if any, elements will
/// need to be implemented in a desugared if expression.
#[allow(clippy::enum_variant_names)]
#[derive(Debug, Clone)]
pub enum Scrutinee {
    CatchAll {
        span: Span,
    },
    Literal {
        value: Literal,
        span: Span,
    },
    Variable {
        name: Ident,
        span: Span,
    },
    StructScrutinee {
        struct_name: Ident,
        fields: Vec<StructScrutineeField>,
        span: Span,
    },
    EnumScrutinee {
        call_path: CallPath,
        value: Box<Scrutinee>,
        span: Span,
    },
    Tuple {
        elems: Vec<Scrutinee>,
        span: Span,
    },
}

#[derive(Debug, Clone)]
pub struct StructScrutineeField {
    pub field: Ident,
    pub scrutinee: Option<Scrutinee>,
    pub span: Span,
}

impl Scrutinee {
    pub fn span(&self) -> Span {
        match self {
            Scrutinee::CatchAll { span } => span.clone(),
            Scrutinee::Literal { span, .. } => span.clone(),
            Scrutinee::Variable { span, .. } => span.clone(),
            Scrutinee::StructScrutinee { span, .. } => span.clone(),
            Scrutinee::EnumScrutinee { span, .. } => span.clone(),
            Scrutinee::Tuple { span, .. } => span.clone(),
        }
    }

    /// Given some `Scrutinee` `self`, analyze `self` and return all instances
    /// of possible dependencies. A "possible dependency" is a `Scrutinee` that
    /// resolves to one or more `TypeInfo::Custom`.
    ///
    /// For example, this `Scrutinee`:
    ///
    /// ```ignore
    /// Scrutinee::EnumScrutinee {
    ///   call_path: CallPath {
    ///     prefixes: ["Data"]
    ///     suffix: "A"
    ///   },
    ///   value: Scrutinee::StructScrutinee {
    ///     struct_name: "Foo",
    ///     fields: [
    ///         StructScrutineeField {
    ///             scrutinee: Scrutinee::StructScrutinee {
    ///                 struct_name: "Bar",
    ///                 fields: [
    ///                     StructScrutineeField {
    ///                         scrutinee: Scrutinee::Literal { .. },
    ///                         ..
    ///                     }
    ///                 ],
    ///                 ..
    ///             },
    ///             ..
    ///         }
    ///     ],
    ///     ..
    ///   }
    ///   ..
    /// }
    /// ```
    ///
    /// would resolve to this list of approximate `TypeInfo` dependencies:
    ///
    /// ```ignore
    /// [
    ///     TypeInfo::Custom {
    ///         name: "Data",
    ///         ..
    ///     },
    ///     TypeInfo::Custom {
    ///         name: "Foo",
    ///         ..
    ///     },
    ///     TypeInfo::Custom {
    ///         name: "Bar",
    ///         ..
    ///     },
    /// ]
    /// ```
    pub(crate) fn gather_approximate_typeinfo_dependencies(&self) -> Vec<TypeInfo> {
        match self {
            Scrutinee::StructScrutinee {
                struct_name,
                fields,
                ..
            } => {
                let name = vec![TypeInfo::Custom {
                    name: struct_name.clone(),
                    type_arguments: vec![],
                }];
                let fields = fields
                    .iter()
                    .flat_map(|StructScrutineeField { scrutinee, .. }| match scrutinee {
                        Some(scrutinee) => scrutinee.gather_approximate_typeinfo_dependencies(),
                        None => vec![],
                    })
                    .collect::<Vec<TypeInfo>>();
                vec![name, fields].concat()
            }
            Scrutinee::EnumScrutinee {
                call_path, value, ..
            } => {
                let enum_name = call_path.prefixes.last().unwrap_or(&call_path.suffix);
                let name = vec![TypeInfo::Custom {
                    name: enum_name.clone(),
                    type_arguments: vec![],
                }];
                let value = value.gather_approximate_typeinfo_dependencies();
                vec![name, value].concat()
            }
            Scrutinee::Tuple { elems, .. } => elems
                .iter()
                .flat_map(|scrutinee| scrutinee.gather_approximate_typeinfo_dependencies())
                .collect::<Vec<TypeInfo>>(),
            Scrutinee::Literal { .. } | Scrutinee::CatchAll { .. } | Scrutinee::Variable { .. } => {
                vec![]
            }
        }
    }
}