resl 0.1.0

A modern configuration and serialization language with variables, expressions, and dynamic runtime evaluation
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

use crate::{expr::Expr, function::Fn, state::EvalState, value::Value};

pub(crate) const BUILTIN_FUNCTIONS: [(&str, Fn); 7] = [
    ("debug", Fn::BuiltIn(debug)),
    ("type_of", Fn::BuiltIn(type_of)),
    ("length", Fn::BuiltIn(length)),
    ("to_str", Fn::BuiltIn(to_str)),
    ("concat", Fn::BuiltIn(concat)),
    ("push", Fn::BuiltIn(push)),
    ("insert", Fn::BuiltIn(insert)),
];

pub(crate) fn debug(state: &mut EvalState, args: Vec<Expr>) -> Value {
    if args.len() != 1 {
        return Value::Null;
    }

    let value = args[0].to_owned().evaluate(state);
    println!("{}", value);
    value
}

pub(crate) fn type_of(state: &mut EvalState, args: Vec<Expr>) -> Value {
    if args.len() != 1 {
        return Value::Null;
    }

    let arg = args[0].to_owned().evaluate(state);

    let type_str = match arg {
        Value::Null => "null",
        Value::Boolean(_) => "boolean",
        Value::Integer(_) => "integer",
        Value::Float(_) => "float",
        Value::String(_) => "string",
        Value::List(_) => "list",
        Value::Map(_) => "map",
    };

    Value::String(type_str.to_string())
}

pub(crate) fn length(state: &mut EvalState, args: Vec<Expr>) -> Value {
    if args.len() != 1 {
        return Value::Null;
    }

    let arg = args[0].to_owned().evaluate(state);

    match arg {
        Value::String(s) => Value::Integer(s.chars().count() as i64),
        Value::List(arr) => Value::Integer(arr.len() as i64),
        Value::Map(map) => Value::Integer(map.len() as i64),
        _ => Value::Null,
    }
}

pub(crate) fn to_str(state: &mut EvalState, args: Vec<Expr>) -> Value {
    if args.len() != 1 {
        return Value::Null;
    }

    let arg = args[0].to_owned().evaluate(state);
    Value::String(arg.to_string())
}

pub(crate) fn concat(state: &mut EvalState, args: Vec<Expr>) -> Value {
    let mut string = String::new();

    for arg in args {
        if let Value::String(str) = arg.evaluate(state) {
            string.push_str(&str)
        }
    }

    if string.is_empty() {
        return Value::Null;
    }

    Value::String(string)
}

pub(crate) fn push(state: &mut EvalState, args: Vec<Expr>) -> Value {
    if args.len() != 2 {
        return Value::Null;
    }

    let collection = args[0].to_owned().evaluate(state);
    let value = args[1].to_owned().evaluate(state);

    match collection {
        Value::List(mut arr) => {
            arr.push(value);
            Value::List(arr)
        }
        _ => Value::Null,
    }
}

pub(crate) fn insert(state: &mut EvalState, args: Vec<Expr>) -> Value {
    if args.len() != 3 {
        return Value::Null;
    }

    let collection = args[0].to_owned().evaluate(state);
    let key = args[1].to_owned().evaluate(state);
    let value = args[2].to_owned().evaluate(state);

    match collection {
        Value::Map(mut map) => {
            if let Value::String(key_str) = key {
                map.insert(key_str, value);
                Value::Map(map)
            } else {
                Value::Null
            }
        }
        Value::List(mut arr) => {
            if let Value::Integer(index) = key {
                let idx = if index < 0 {
                    (arr.len() as i64 + index) as usize
                } else {
                    index as usize
                };
                if idx <= arr.len() {
                    arr.insert(idx, value);
                    return Value::List(arr);
                }
            }
            Value::Null
        }
        _ => Value::Null,
    }
}