systemprompt_identifiers/
locale.rs

1//! BCP-47-lite locale identifier.
2//!
3//! Accepts the common subset of language tags: a 2- or 3-letter primary
4//! subtag, optionally followed by additional `-`-separated subtags of 2-8
5//! alphanumerics each. Total length capped at 35 characters per RFC 5646.
6//! Comparison is case-sensitive on the lowercase primary subtag; callers
7//! that need full BCP-47 canonicalisation should add the `language-tags`
8//! crate when the requirement arrives.
9//!
10//! Copyright (c) systemprompt.io — Business Source License 1.1.
11//! See <https://systemprompt.io> for licensing details.
12
13use crate::error::IdValidationError;
14use crate::{DbValue, ToDbValue};
15use schemars::JsonSchema;
16use serde::{Deserialize, Serialize};
17use std::fmt;
18
19const MAX_LEN: usize = 35;
20
21#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, JsonSchema)]
22#[cfg_attr(feature = "sqlx", derive(sqlx::Type))]
23#[cfg_attr(feature = "sqlx", sqlx(transparent))]
24#[serde(transparent)]
25pub struct LocaleCode(String);
26
27impl LocaleCode {
28    pub fn try_new(value: impl Into<String>) -> Result<Self, IdValidationError> {
29        let value = value.into();
30        if value.is_empty() {
31            return Err(IdValidationError::empty("LocaleCode"));
32        }
33        if value.len() > MAX_LEN {
34            return Err(IdValidationError::invalid(
35                "LocaleCode",
36                "exceeds 35 characters",
37            ));
38        }
39        let mut subtags = value.split('-');
40        let primary = subtags.next().unwrap_or("");
41        let plen = primary.len();
42        if !(2..=3).contains(&plen) || !primary.chars().all(|c| c.is_ascii_lowercase()) {
43            return Err(IdValidationError::invalid(
44                "LocaleCode",
45                "primary subtag must be 2-3 lowercase ASCII letters",
46            ));
47        }
48        for sub in subtags {
49            let len = sub.len();
50            if !(2..=8).contains(&len) || !sub.chars().all(|c| c.is_ascii_alphanumeric()) {
51                return Err(IdValidationError::invalid(
52                    "LocaleCode",
53                    "subtag must be 2-8 alphanumeric ASCII characters",
54                ));
55            }
56        }
57        Ok(Self(value))
58    }
59
60    #[must_use]
61    pub fn english() -> Self {
62        Self("en".to_owned())
63    }
64
65    #[must_use]
66    pub fn as_str(&self) -> &str {
67        &self.0
68    }
69}
70
71impl fmt::Display for LocaleCode {
72    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
73        write!(f, "{}", self.0)
74    }
75}
76
77impl TryFrom<String> for LocaleCode {
78    type Error = IdValidationError;
79
80    fn try_from(s: String) -> Result<Self, Self::Error> {
81        Self::try_new(s)
82    }
83}
84
85impl TryFrom<&str> for LocaleCode {
86    type Error = IdValidationError;
87
88    fn try_from(s: &str) -> Result<Self, Self::Error> {
89        Self::try_new(s)
90    }
91}
92
93impl std::str::FromStr for LocaleCode {
94    type Err = IdValidationError;
95
96    fn from_str(s: &str) -> Result<Self, Self::Err> {
97        Self::try_new(s)
98    }
99}
100
101impl AsRef<str> for LocaleCode {
102    fn as_ref(&self) -> &str {
103        &self.0
104    }
105}
106
107impl<'de> Deserialize<'de> for LocaleCode {
108    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
109    where
110        D: serde::Deserializer<'de>,
111    {
112        let s = String::deserialize(deserializer)?;
113        Self::try_new(s).map_err(serde::de::Error::custom)
114    }
115}
116
117impl ToDbValue for LocaleCode {
118    fn to_db_value(&self) -> DbValue {
119        DbValue::String(self.0.clone())
120    }
121}
122
123impl ToDbValue for &LocaleCode {
124    fn to_db_value(&self) -> DbValue {
125        DbValue::String(self.0.clone())
126    }
127}
systemprompt_identifiers/locale.rs

systemprompt_identifiers/
locale.rs
