basalt_tui/
stylized_text.rs

1//! Text stylizing.
2//!
3//! The [`stylize`] function allows converting regular A-z letters and 0–9 numbers into stylized
4//! variants. The text is converted according to the [`FontStyle`] enum.
5//!
6//! # Examples
7//!
8//! ```
9//! use basalt_tui::stylized_text::{FontStyle, stylize};
10//!
11//! assert_eq!(stylize("My Heading", FontStyle::FrakturBold), "𝕸𝖞 𝕳𝖊𝖆𝖉𝖎𝖓𝖌");
12//! ```
13
14/// Enum representing different font styles.
15///
16/// - BlackBoardBold (𝔹𝕝𝕒𝕔𝕜𝔹𝕠𝕒𝕣𝕕𝔹𝕠𝕝𝕕)
17/// - FrakturBold (𝕱𝖗𝖆𝖐𝖙𝖚𝖗𝕭𝖔𝖑𝖉)
18/// - Script (𝓢𝓬𝓻𝓲𝓹𝓽)
19#[derive(Debug, Clone, Copy, PartialEq, serde::Deserialize)]
20#[serde(rename_all = "kebab-case")]
21pub enum FontStyle {
22    /// Blackboard Bold (Double-struck) style (e.g., 𝕋𝕚𝕥𝕝𝕖).
23    BlackBoardBold,
24    /// Bold Fraktur style. (e.g., 𝕿𝖎𝖙𝖑𝖊)
25    FrakturBold,
26    /// Script style. (e.g., 𝓣𝓲𝓽𝓵𝓮)
27    Script,
28}
29
30/// Stylizes the given input string using the specified [`FontStyle`].
31///
32/// Each character in the input is mapped to its corresponding stylized Unicode character based on
33/// the provided style. Characters that do not have a stylized equivalent are returned unchanged.
34///
35/// # Examples
36///
37/// ```
38/// use basalt_tui::stylized_text::{FontStyle, stylize};
39///
40/// assert_eq!(stylize("Black Board Bold", FontStyle::BlackBoardBold), "𝔹𝕝𝕒𝕔𝕜 𝔹𝕠𝕒𝕣𝕕 𝔹𝕠𝕝𝕕");
41/// assert_eq!(stylize("Fraktur Bold", FontStyle::FrakturBold), "𝕱𝖗𝖆𝖐𝖙𝖚𝖗 𝕭𝖔𝖑𝖉");
42/// assert_eq!(stylize("Script", FontStyle::Script), "𝓢𝓬𝓻𝓲𝓹𝓽");
43/// ```
44pub fn stylize(input: &str, style: FontStyle) -> String {
45    input.chars().map(|c| stylize_char(c, style)).collect()
46}
47
48/// Returns the stylized Unicode character for a given `char` and [`FontStyle`].
49///
50/// Letters between A-z and number 0-9 are stylized. Characters outside the stylized range (e.g.,
51/// punctuation) are returned as-is.
52///
53/// To find the corresponding stylized character, we add the remainder to the unicode character
54/// range, which is achieved by subtracting the start position from the input `char`.
55fn stylize_char(c: char, style: FontStyle) -> char {
56    match style {
57        FontStyle::BlackBoardBold => match c {
58            'C' => char::from_u32(0x2102),
59            'H' => char::from_u32(0x210D),
60            'N' => char::from_u32(0x2115),
61            'P' => char::from_u32(0x2119),
62            'Q' => char::from_u32(0x211A),
63            'R' => char::from_u32(0x211D),
64            'Z' => char::from_u32(0x2124),
65            'A'..='Z' => char::from_u32(0x1D538 + (c as u32 - 'A' as u32)),
66            'a'..='z' => char::from_u32(0x1D552 + (c as u32 - 'a' as u32)),
67            '0'..='9' => char::from_u32(0x1D7D8 + (c as u32 - '0' as u32)),
68            _ => None,
69        },
70        FontStyle::FrakturBold => match c {
71            'A'..='Z' => char::from_u32(0x1D56C + (c as u32 - 'A' as u32)),
72            'a'..='z' => char::from_u32(0x1D586 + (c as u32 - 'a' as u32)),
73            '0'..='9' => char::from_u32(0x1D7CE + (c as u32 - '0' as u32)),
74            _ => None,
75        },
76        FontStyle::Script => match c {
77            'A'..='Z' => char::from_u32(0x1D4D0 + (c as u32 - 'A' as u32)),
78            'a'..='z' => char::from_u32(0x1D4EA + (c as u32 - 'a' as u32)),
79            '0'..='9' => char::from_u32(0x1D7CE + (c as u32 - '0' as u32)),
80            _ => None,
81        },
82    }
83    .unwrap_or(c)
84}
85
86#[cfg(test)]
87mod tests {
88    use similar_asserts::assert_eq;
89
90    use super::*;
91
92    #[test]
93    fn test_stylize() {
94        let text = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
95        let tests = [
96            (
97                FontStyle::Script,
98                "𝓐𝓑𝓒𝓓𝓔𝓕𝓖𝓗𝓘𝓙𝓚𝓛𝓜𝓝𝓞𝓟𝓠𝓡𝓢𝓣𝓤𝓥𝓦𝓧𝓨𝓩𝓪𝓫𝓬𝓭𝓮𝓯𝓰𝓱𝓲𝓳𝓴𝓵𝓶𝓷𝓸𝓹𝓺𝓻𝓼𝓽𝓾𝓿𝔀𝔁𝔂𝔃𝟎𝟏𝟐𝟑𝟒𝟓𝟔𝟕𝟖𝟗",
99            ),
100            (
101                FontStyle::FrakturBold,
102                "𝕬𝕭𝕮𝕯𝕰𝕱𝕲𝕳𝕴𝕵𝕶𝕷𝕸𝕹𝕺𝕻𝕼𝕽𝕾𝕿𝖀𝖁𝖂𝖃𝖄𝖅𝖆𝖇𝖈𝖉𝖊𝖋𝖌𝖍𝖎𝖏𝖐𝖑𝖒𝖓𝖔𝖕𝖖𝖗𝖘𝖙𝖚𝖛𝖜𝖝𝖞𝖟𝟎𝟏𝟐𝟑𝟒𝟓𝟔𝟕𝟖𝟗",
103            ),
104            (
105                FontStyle::BlackBoardBold,
106                "𝔸𝔹ℂ𝔻𝔼𝔽𝔾ℍ𝕀𝕁𝕂𝕃𝕄ℕ𝕆ℙℚℝ𝕊𝕋𝕌𝕍𝕎𝕏𝕐ℤ𝕒𝕓𝕔𝕕𝕖𝕗𝕘𝕙𝕚𝕛𝕜𝕝𝕞𝕟𝕠𝕡𝕢𝕣𝕤𝕥𝕦𝕧𝕨𝕩𝕪𝕫𝟘𝟙𝟚𝟛𝟜𝟝𝟞𝟟𝟠𝟡",
107            ),
108        ];
109
110        tests
111            .iter()
112            .for_each(|test| assert_eq!(stylize(text, test.0), test.1));
113    }
114}
basalt_tui/stylized_text.rs

basalt_tui/
stylized_text.rs
