rl_lang/docs/entries/concepts/errors/
mod.rs

1use crate::docs::entry::{ConceptCategory, ConceptEntry, DescriptionEntry, DescriptionKind};
2
3pub static ERROR_TYPE: ConceptEntry = ConceptEntry {
4    name: "result",
5    descriptions: &[
6        DescriptionEntry {
7            description: "`result[T]` is a type that holds either `ok(value)` on success or `err(value)` on failure",
8            examples: &[
9                "dec result[int]    r = ok(42)",
10                "dec result[string] e = err(\"not found\")",
11                "dec result[int]    r = err(404)",
12            ],
13            kind: DescriptionKind::Explanation,
14            title: None,
15            expected_output: &[],
16        },
17        DescriptionEntry {
18            description: "`ok(value)` and `err(value)` are the two constructors; both wrap any non-result value",
19            examples: &[
20                "dec result[int] r = ok(100)",
21                "dec result[int] r = err(0)",
22                "dec result[string] r = ok(\"hello\")",
23            ],
24            kind: DescriptionKind::Explanation,
25            title: None,
26            expected_output: &[],
27        },
28        DescriptionEntry {
29            description: "check which variant you have with `is_ok` and `is_err` from `std::res`",
30            examples: &[
31                "get is_ok, is_err from std::res\ndec result[int] r = ok(42)\nprintln(is_ok(r))   // true\nprintln(is_err(r))  // false",
32            ],
33            kind: DescriptionKind::Explanation,
34            title: None,
35            expected_output: &[],
36        },
37        DescriptionEntry {
38            description: "extract the inner value with `result_unwrap` (ok) or `result_unwrap_err` (err) from `std::res`",
39            examples: &[
40                "get result_unwrap from std::res\ndec result[int] r = ok(10)\nprintln(result_unwrap(r))  // 10",
41                "get result_unwrap_err from std::res\ndec result[int] r = err(\"oops\")\nprintln(result_unwrap_err(r))  // oops",
42            ],
43            kind: DescriptionKind::Explanation,
44            title: None,
45            expected_output: &[],
46        },
47        DescriptionEntry {
48            description: "`result_unwrap_or(r, default)` returns the ok value or a fallback if err",
49            examples: &[
50                "get result_unwrap_or from std::res\ndec result[int] r = err(\"fail\")\nprintln(result_unwrap_or(r, 0))  // 0",
51            ],
52            kind: DescriptionKind::Explanation,
53            title: None,
54            expected_output: &[],
55        },
56        DescriptionEntry {
57            description: "functions that may fail should return `result[T]` and the caller checks with `is_ok` / `is_err`",
58            examples: &[
59                "fn divide(int a, int b) -> result[int] {\n    if b == 0 {\n        return err(\"division by zero\")\n    }\n    return ok(a / b)\n}\n\ndec result[int] r = divide(10, 2)\nif is_ok(r) {\n    println(result_unwrap(r))  // 5\n}",
60            ],
61            kind: DescriptionKind::Explanation,
62            title: None,
63            expected_output: &[],
64        },
65        DescriptionEntry {
66            description: "`result_map` transforms the ok value; `result_map_err` transforms the err value - both pass the other variant through unchanged",
67            examples: &[
68                "get result_map from std::res\ndec result[int] r = ok(5)\ndec result[int] r2 = result_map(r, fn(int x) -> int { return x * 2 })\nprintln(result_unwrap(r2))  // 10",
69            ],
70            kind: DescriptionKind::Explanation,
71            title: None,
72            expected_output: &[],
73        },
74        DescriptionEntry {
75            description: "`error[T]` is a separate wrapper type from `result[T]` - construct it with `error(value)`, check with `is_error` from `std::res`, and unwrap with `error_unwrap`",
76            examples: &[
77                "get is_error, error_unwrap from std::res\ndec error e = error(\"disk full\")\nprintln(is_error(e))          // true\nprintln(error_unwrap(e))      // \"disk full\"",
78            ],
79            kind: DescriptionKind::Explanation,
80            title: None,
81            expected_output: &[],
82        },
83        DescriptionEntry {
84            description: "an `error` cannot wrap another `error` - this raises a runtime error",
85            examples: &["dec error e = error(error(\"oops\"))  // runtime error"],
86            kind: DescriptionKind::Pitfall,
87            title: None,
88            expected_output: &[],
89        },
90    ],
91    summary: "",
92    category: ConceptCategory::Syntax,
93    prerequisites: &[],
94    pitfalls: &[],
95    related: &[],
96    related_stdlib: &[],
97    since: None,
98};
rl_lang/docs/entries/concepts/errors/mod.rs

rl_lang/docs/entries/concepts/errors/
mod.rs
