maid-lang 1.1.0

Maid Programming Language
Documentation 
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
151
152
153

use std::{cell::RefCell, rc::Rc, sync::Arc};

use crate::{
    errors::standard_error::StandardError,
    interpreting::{
        context::Context, interpreter::Interpreter, runtime_result::RuntimeResult,
        symbol_table::SymbolTable,
    },
    lexing::position::Position,
    nodes::ast_node::AstNode,
    values::{number::Number, value::Value},
};

#[derive(Debug, Clone)]
pub struct Function {
    pub name: String,
    pub body_node: Box<AstNode>,
    pub arg_names: Arc<[String]>,
    pub should_auto_return: bool,
    pub context: Option<Rc<RefCell<Context>>>,
    pub pos_start: Option<Position>,
    pub pos_end: Option<Position>,
}

impl Function {
    pub fn new(
        name: String,
        body_node: Box<AstNode>,
        arg_names: &[String],
        should_auto_return: bool,
    ) -> Self {
        Self {
            name,
            body_node,
            arg_names: Arc::from(arg_names),
            should_auto_return,
            context: None,
            pos_start: None,
            pos_end: None,
        }
    }

    pub fn generate_new_context(&self) -> Rc<RefCell<Context>> {
        let mut new_context = Context::new(
            self.name.clone(),
            Some(self.context.as_ref().unwrap().clone()),
            self.pos_start.clone(),
        );
        let parent_st = self
            .context
            .as_ref()
            .unwrap()
            .borrow()
            .symbol_table
            .as_ref()
            .unwrap()
            .clone();
        new_context.symbol_table = Some(Rc::new(RefCell::new(SymbolTable::new(Some(parent_st)))));

        Rc::new(RefCell::new(new_context))
    }

    pub fn check_args(&self, arg_names: &[String], args: &[Value]) -> RuntimeResult {
        let mut result = RuntimeResult::new();

        if args.len() > arg_names.len() || args.len() < arg_names.len() {
            return result.failure(Some(StandardError::new(
                "invalid function call",
                self.pos_start.as_ref().unwrap().clone(),
                self.pos_end.as_ref().unwrap().clone(),
                Some(
                    format!(
                        "{} takes {} positional argument(s) but the program gave {}",
                        self.name,
                        arg_names.len(),
                        args.len()
                    )
                    .as_str(),
                ),
            )));
        }

        result.success(None)
    }

    pub fn populate_args(
        &self,
        arg_names: &[String],
        args: &[Value],
        expr_ctx: Rc<RefCell<Context>>,
    ) {
        for i in 0..args.len() {
            let arg_name = arg_names[i].clone();
            let mut arg_value = args[i].clone();
            arg_value.set_context(Some(expr_ctx.clone()));

            expr_ctx
                .borrow_mut()
                .symbol_table
                .as_mut()
                .unwrap()
                .borrow_mut()
                .set(arg_name.to_string(), Some(arg_value));
        }
    }

    pub fn check_and_populate_args(
        &self,
        arg_names: &[String],
        args: &[Value],
        expr_ctx: Rc<RefCell<Context>>,
    ) -> RuntimeResult {
        let mut result = RuntimeResult::new();
        result.register(self.check_args(arg_names, args));

        if result.should_return() {
            return result;
        }

        self.populate_args(arg_names, args, expr_ctx);

        result.success(None)
    }

    pub fn execute(&self, args: &[Value]) -> RuntimeResult {
        let mut result = RuntimeResult::new();
        let mut interpreter = Interpreter::new();
        let exec_context = self.generate_new_context();

        result.register(self.check_and_populate_args(&self.arg_names, args, exec_context.clone()));

        if result.should_return() {
            return result;
        }

        let value =
            result.register(interpreter.visit(self.body_node.clone(), exec_context.clone()));

        if result.should_return() && result.func_return_value.is_none() {
            return result;
        }

        let return_value = if self.should_auto_return { value } else { None }
            .or(result.func_return_value.clone())
            .or(Some(Number::null_value()));

        result.success(return_value)
    }

    pub fn as_string(&self) -> String {
        format!("function: {}", self.name).to_string()
    }
}