Struct BoxCharsBuilder 

pub struct BoxCharsBuilder { /* private fields */ }

Builder for creating custom BoxChars with a fluent, type-safe API.

The builder pattern provides an ergonomic way to construct custom box characters with method chaining. All methods are const fn where possible for compile-time evaluation. The builder starts with invisible characters (NONE) and allows selective customization.

Design Patterns

Uniform Styling

Use the convenience methods for consistent appearance:

• corners() - Sets all four corners to the same character
• horizontal() - Sets top and bottom borders
• vertical() - Sets left and right borders

Selective Overrides

Start with uniform styling, then override specific positions:

use cli_boxes::BoxChars;

let mixed = BoxChars::builder()
    .corners('●')           // Set all corners
    .horizontal('═')        // Set horizontal borders
    .vertical('║')          // Set vertical borders
    .top_left('╔')         // Override just top-left
    .build();

Asymmetric Designs

Create unique, asymmetric box styles:

use cli_boxes::BoxChars;

let asymmetric = BoxChars::builder()
    .top_left('╭').top('─').top_right('╮')
    .left('│').right('│')
    .bottom_left('└').bottom('─').bottom_right('┘')
    .build();

Theme-Based Construction

use cli_boxes::BoxChars;

fn create_theme_box(theme: &str) -> BoxChars {
    let mut builder = BoxChars::builder();
     
    match theme {
        "minimal" => builder.corners('+').horizontal('-').vertical('|'),
        "fancy" => builder.corners('●').horizontal('═').vertical('║'),
        "retro" => builder.corners('*').horizontal('=').vertical(':'),
        _ => builder.corners('?').horizontal('?').vertical('?'),
    }.build()
}

Performance

The builder uses const fn methods where possible, allowing compile-time evaluation when used with constant inputs. The final build() call is zero-cost, simply returning the constructed BoxChars struct.

Implementations

impl BoxCharsBuilder

pub const fn corners(self, char: char) -> Self

Sets all corner characters to the same value.

pub const fn horizontal(self, char: char) -> Self

Sets both horizontal border characters (top and bottom) to the same value.

pub const fn vertical(self, char: char) -> Self

Sets both vertical border characters (left and right) to the same value.

pub const fn top_left(self, char: char) -> Self

Sets the top-left corner character.

pub const fn top(self, char: char) -> Self

Sets the top border character.

pub const fn top_right(self, char: char) -> Self

Sets the top-right corner character.

pub const fn right(self, char: char) -> Self

Sets the right border character.

pub const fn bottom_right(self, char: char) -> Self

Sets the bottom-right corner character.

pub const fn bottom(self, char: char) -> Self

Sets the bottom border character.

pub const fn bottom_left(self, char: char) -> Self

Sets the bottom-left corner character.

pub const fn left(self, char: char) -> Self

Sets the left border character.

pub const fn build(self) -> BoxChars

Builds and returns the final BoxChars.

Trait Implementations

impl Clone for BoxCharsBuilder

fn clone(&self) -> BoxCharsBuilder

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for BoxCharsBuilder

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for BoxCharsBuilder

fn default() -> Self

Returns the “default value” for a type.