shelly-shell 0.5.2

A Rust based Unix style shell with a typed and structured language syntax.
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


use std::{ collections::{ BTreeMap, BTreeSet }, ops::{ Index, IndexMut }, sync::Arc };

use crate::language::{ parser::{ EditorAnalysis, editor::analyze_editor_tree },
                       text::span::SourceSpan };

mod semantic;
pub mod highlight;


#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum SymbolKind
{
    Variable,
    Type,
    Function,
    Method,
    Builtin,
    Alias,
    ExternalCommand,
    Field,
    EnumVariant,
    Module,
}


#[derive(Clone, Debug, PartialEq, Eq)]
pub struct SymbolDescriptor
{
    pub kind: SymbolKind,
    pub type_id: Option<usize>,
    pub return_type: Option<usize>,
}

impl SymbolDescriptor
{
    pub fn new(kind: SymbolKind, type_id: Option<usize>) -> Self
    { Self { kind, type_id, return_type: None } }
}


/**
 * Owned type relationships only. No value, receiver, getter, bytecode, or module loader
 * survives the snapshot boundary. Registered IDs retain their nominal identities.
 */
#[derive(Clone, Debug, Default)]
pub struct TypeDescriptor
{
    pub name: String,
    pub parent: Option<usize>,
    pub item: Option<usize>,
    pub key: Option<usize>,
    pub fields: BTreeMap<String, SymbolDescriptor>,
    pub variants: BTreeSet<String>,
    pub methods: BTreeMap<String, SymbolDescriptor>,
    pub call_result: Option<usize>,
}


#[derive(Clone, Debug, Default)]
pub struct SymbolSnapshot
{
    pub symbols: BTreeMap<String, SymbolDescriptor>,
    pub types: Arc<Vec<TypeDescriptor>>,
    pub external_commands: BTreeSet<String>,
}


/**
 * Share the immutable registered table between editing passes. Provisional types are
 * appended locally, so ordinary keystrokes do not copy every known method and field.
 */
#[derive(Clone, Debug)]
pub struct TypeTable
{
    registered: Arc<Vec<TypeDescriptor>>,
    local: Vec<TypeDescriptor>,
}

impl TypeTable
{
    pub(super) fn new(registered: Arc<Vec<TypeDescriptor>>) -> Self
    { Self { registered, local: Vec::new() } }

    pub fn get(&self, id: usize) -> Option<&TypeDescriptor>
    {
        if id < self.registered.len() { self.registered.get(id) }
        else { self.local.get(id - self.registered.len()) }
    }

    pub(super) fn len(&self) -> usize { self.registered.len() + self.local.len() }

    pub(super) fn push(&mut self, descriptor: TypeDescriptor) { self.local.push(descriptor); }
}

impl Index<usize> for TypeTable
{
    type Output = TypeDescriptor;

    fn index(&self, id: usize) -> &Self::Output { self.get(id).unwrap() }
}

impl IndexMut<usize> for TypeTable
{
    fn index_mut(&mut self, id: usize) -> &mut Self::Output
    {
        // Registered descriptors cannot be changed by analysis.
        &mut self.local[id - self.registered.len()]
    }
}


#[derive(Clone, Debug, PartialEq, Eq)]
pub struct SemanticFact
{
    pub span: SourceSpan,
    pub kind: SymbolKind,
    pub type_id: Option<usize>,
}


pub struct SemanticAnalysis
{
    pub source: EditorAnalysis,
    pub facts: Vec<SemanticFact>,
    // Includes provisional local types; IDs in facts index this owned table.
    pub types: TypeTable,
}


/**
 * Resolve understood references against existing information. This is source tooling,
 * not type checking: uncertain types and names remain unclassified, without diagnostics.
 */
pub fn analyze_semantics(source: &str, snapshot: &SymbolSnapshot) -> SemanticAnalysis
{
    let (analysis, statements) = analyze_editor_tree(source);
    let (facts, types) = semantic::classify(source, &analysis, &statements, snapshot);
    SemanticAnalysis { source: analysis, facts, types }
}