aver/services/
random.rs

1/// Random service — effectful random number generation.
2///
3/// Methods:
4///   Random.int(min, max)  — random Int in [min, max] inclusive; ! [Random]
5///   Random.float()        — random Float in [0.0, 1.0); ! [Random]
6///
7/// Backed by `aver_rt::random` (OS entropy via `rand` crate).
8use std::collections::HashMap;
9use std::sync::Arc as Rc;
10
11use crate::nan_value::{Arena, NanValue};
12use crate::value::{RuntimeError, Value};
13
14pub fn register(global: &mut HashMap<String, Value>) {
15    let mut members = HashMap::new();
16    for method in &["int", "float"] {
17        members.insert(
18            method.to_string(),
19            Value::Builtin(format!("Random.{}", method)),
20        );
21    }
22    global.insert(
23        "Random".to_string(),
24        Value::Namespace {
25            name: "Random".to_string(),
26            members,
27        },
28    );
29}
30
31pub const DECLARED_EFFECTS: &[&str] = &["Random.int", "Random.float"];
32
33pub fn effects(name: &str) -> &'static [&'static str] {
34    match name {
35        "Random.int" => &["Random.int"],
36        "Random.float" => &["Random.float"],
37        _ => &[],
38    }
39}
40
41pub fn call(name: &str, args: &[Value]) -> Option<Result<Value, RuntimeError>> {
42    match name {
43        "Random.int" => Some(random_int(args)),
44        "Random.float" => Some(random_float(args)),
45        _ => None,
46    }
47}
48
49fn random_int(args: &[Value]) -> Result<Value, RuntimeError> {
50    if args.len() != 2 {
51        return Err(RuntimeError::Error(format!(
52            "Random.int takes 2 arguments (min, max), got {}",
53            args.len()
54        )));
55    }
56    let Value::Int(min) = &args[0] else {
57        return Err(RuntimeError::Error(
58            "Random.int: first argument must be an Int".to_string(),
59        ));
60    };
61    let Value::Int(max) = &args[1] else {
62        return Err(RuntimeError::Error(
63            "Random.int: second argument must be an Int".to_string(),
64        ));
65    };
66
67    match aver_rt::random::random_int(*min, *max) {
68        Ok(value) => Ok(Value::Int(value)),
69        Err(msg) => Err(RuntimeError::Error(msg)),
70    }
71}
72
73fn random_float(args: &[Value]) -> Result<Value, RuntimeError> {
74    if !args.is_empty() {
75        return Err(RuntimeError::Error(format!(
76            "Random.float takes 0 arguments, got {}",
77            args.len()
78        )));
79    }
80    Ok(Value::Float(aver_rt::random::random_float()))
81}
82
83// ─── NanValue-native API ─────────────────────────────────────────────────────
84
85pub fn register_nv(global: &mut HashMap<String, NanValue>, arena: &mut Arena) {
86    let methods = &["int", "float"];
87    let mut members: Vec<(Rc<str>, NanValue)> = Vec::with_capacity(methods.len());
88    for method in methods {
89        let idx = arena.push_builtin(&format!("Random.{}", method));
90        members.push((Rc::from(*method), NanValue::new_builtin(idx)));
91    }
92    let ns_idx = arena.push(crate::nan_value::ArenaEntry::Namespace {
93        name: Rc::from("Random"),
94        members,
95    });
96    global.insert("Random".to_string(), NanValue::new_namespace(ns_idx));
97}
98
99pub fn call_nv(
100    name: &str,
101    args: &[NanValue],
102    arena: &mut Arena,
103) -> Option<Result<NanValue, RuntimeError>> {
104    match name {
105        "Random.int" => Some(random_int_nv(args, arena)),
106        "Random.float" => Some(random_float_nv(args, arena)),
107        _ => None,
108    }
109}
110
111fn random_int_nv(args: &[NanValue], arena: &mut Arena) -> Result<NanValue, RuntimeError> {
112    if args.len() != 2 {
113        return Err(RuntimeError::Error(format!(
114            "Random.int takes 2 arguments (min, max), got {}",
115            args.len()
116        )));
117    }
118    if !args[0].is_int() {
119        return Err(RuntimeError::Error(
120            "Random.int: first argument must be an Int".to_string(),
121        ));
122    }
123    if !args[1].is_int() {
124        return Err(RuntimeError::Error(
125            "Random.int: second argument must be an Int".to_string(),
126        ));
127    }
128    let min = args[0].as_int(arena);
129    let max = args[1].as_int(arena);
130    match aver_rt::random::random_int(min, max) {
131        Ok(value) => Ok(NanValue::new_int(value, arena)),
132        Err(msg) => Err(RuntimeError::Error(msg)),
133    }
134}
135
136fn random_float_nv(args: &[NanValue], _arena: &mut Arena) -> Result<NanValue, RuntimeError> {
137    if !args.is_empty() {
138        return Err(RuntimeError::Error(format!(
139            "Random.float takes 0 arguments, got {}",
140            args.len()
141        )));
142    }
143    Ok(NanValue::new_float(aver_rt::random::random_float()))
144}
aver/services/random.rs

aver/services/
random.rs
