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occurred Mar 18, 2024 at 15:45

Code fence

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edited Mar 18, 2024 at 7:43

Toby Speight

edited Mar 18, 2024 at 7:43

Toby Speight

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fn main() {
 let commands: [Command; 3] = [
 Command {code: '1', description: String::from("Start your instance")},
 Command {code: '2', description: String::from("Stop your instance")},
 Command {code: 'q', description: String::from("Quit")},
 ];
 
 print_table(&commands);
 
 for cmd in commands.iter() {
 match cmd.code {
 '1' => println!("Starting instance"),
 '2' => println!("Stopping instance"),
 'q' => println!("Quitting"),
 _ => println!("Invalid option"),
 }
 }
}
fn print_table(commands: &[Command; 3]) {
 const BUFFER: usize = 2;
 const HEADING: (&str, &str) = ("Code", "Description");
 const VERTICAL_BAR: &str = "│";
 const HORIZONTAL_SEP: &str = "─";
 
 std::process::Command::new("clear").status().unwrap();
 
 let mut max_lengths: (usize, usize) = (0, 0);
 for cmd in commands.iter() {
 max_lengths.0 = std::cmp::max(max_lengths.0, cmd.code.len_utf8());
 max_lengths.1 = std::cmp::max(max_lengths.1, cmd.description.len());
 }
 max_lengths.0 = std::cmp::max(max_lengths.0, HEADING.0.len());
 max_lengths.1 = std::cmp::max(max_lengths.1, HEADING.1.len());
 
 let horizontal_lines: (&str, &str) = (
 &HORIZONTAL_SEP.repeat(max_lengths.0 + BUFFER),
 &HORIZONTAL_SEP.repeat(max_lengths.1 + BUFFER),
 );
 
 println!("╭{}┬{}╮", horizontal_lines.0, horizontal_lines.1);
 println!("{VERTICAL_BAR}{:^w1$}{VERTICAL_BAR} {:^w2$}{VERTICAL_BAR}", HEADING.0, HEADING.1, w1=max_lengths.0+BUFFER, w2=max_lengths.1+BUFFER-1);
 println!("├{}┼{}┤", horizontal_lines.0, horizontal_lines.1);
 for cmd in commands.iter() {
 println!("{VERTICAL_BAR}{:^w1$}{VERTICAL_BAR} {:<w2$}{VERTICAL_BAR}", cmd.code, cmd.description, w1=max_lengths.0+BUFFER, w2=max_lengths.1+BUFFER-1);
 }
 println!("╰{}┴{}╯", horizontal_lines.0, horizontal_lines.1);
}
struct Command {
 code: char,
 description: String,
}
```

fn main() {
 let commands: [Command; 3] = [
 Command {code: '1', description: String::from("Start your instance")},
 Command {code: '2', description: String::from("Stop your instance")},
 Command {code: 'q', description: String::from("Quit")},
 ];
 
 print_table(&commands);
 
 for cmd in commands.iter() {
 match cmd.code {
 '1' => println!("Starting instance"),
 '2' => println!("Stopping instance"),
 'q' => println!("Quitting"),
 _ => println!("Invalid option"),
 }
 }
}
fn print_table(commands: &[Command; 3]) {
 const BUFFER: usize = 2;
 const HEADING: (&str, &str) = ("Code", "Description");
 const VERTICAL_BAR: &str = "│";
 const HORIZONTAL_SEP: &str = "─";
 
 std::process::Command::new("clear").status().unwrap();
 
 let mut max_lengths: (usize, usize) = (0, 0);
 for cmd in commands.iter() {
 max_lengths.0 = std::cmp::max(max_lengths.0, cmd.code.len_utf8());
 max_lengths.1 = std::cmp::max(max_lengths.1, cmd.description.len());
 }
 max_lengths.0 = std::cmp::max(max_lengths.0, HEADING.0.len());
 max_lengths.1 = std::cmp::max(max_lengths.1, HEADING.1.len());
 
 let horizontal_lines: (&str, &str) = (
 &HORIZONTAL_SEP.repeat(max_lengths.0 + BUFFER),
 &HORIZONTAL_SEP.repeat(max_lengths.1 + BUFFER),
 );
 
 println!("╭{}┬{}╮", horizontal_lines.0, horizontal_lines.1);
 println!("{VERTICAL_BAR}{:^w1$}{VERTICAL_BAR} {:^w2$}{VERTICAL_BAR}", HEADING.0, HEADING.1, w1=max_lengths.0+BUFFER, w2=max_lengths.1+BUFFER-1);
 println!("├{}┼{}┤", horizontal_lines.0, horizontal_lines.1);
 for cmd in commands.iter() {
 println!("{VERTICAL_BAR}{:^w1$}{VERTICAL_BAR} {:<w2$}{VERTICAL_BAR}", cmd.code, cmd.description, w1=max_lengths.0+BUFFER, w2=max_lengths.1+BUFFER-1);
 }
 println!("╰{}┴{}╯", horizontal_lines.0, horizontal_lines.1);
}
struct Command {
 code: char,
 description: String,
}
```

fn main() {
 let commands: [Command; 3] = [
 Command {code: '1', description: String::from("Start your instance")},
 Command {code: '2', description: String::from("Stop your instance")},
 Command {code: 'q', description: String::from("Quit")},
 ];
 
 print_table(&commands);
 
 for cmd in commands.iter() {
 match cmd.code {
 '1' => println!("Starting instance"),
 '2' => println!("Stopping instance"),
 'q' => println!("Quitting"),
 _ => println!("Invalid option"),
 }
 }
}
fn print_table(commands: &[Command; 3]) {
 const BUFFER: usize = 2;
 const HEADING: (&str, &str) = ("Code", "Description");
 const VERTICAL_BAR: &str = "│";
 const HORIZONTAL_SEP: &str = "─";
 
 std::process::Command::new("clear").status().unwrap();
 
 let mut max_lengths: (usize, usize) = (0, 0);
 for cmd in commands.iter() {
 max_lengths.0 = std::cmp::max(max_lengths.0, cmd.code.len_utf8());
 max_lengths.1 = std::cmp::max(max_lengths.1, cmd.description.len());
 }
 max_lengths.0 = std::cmp::max(max_lengths.0, HEADING.0.len());
 max_lengths.1 = std::cmp::max(max_lengths.1, HEADING.1.len());
 
 let horizontal_lines: (&str, &str) = (
 &HORIZONTAL_SEP.repeat(max_lengths.0 + BUFFER),
 &HORIZONTAL_SEP.repeat(max_lengths.1 + BUFFER),
 );
 
 println!("╭{}┬{}╮", horizontal_lines.0, horizontal_lines.1);
 println!("{VERTICAL_BAR}{:^w1$}{VERTICAL_BAR} {:^w2$}{VERTICAL_BAR}", HEADING.0, HEADING.1, w1=max_lengths.0+BUFFER, w2=max_lengths.1+BUFFER-1);
 println!("├{}┼{}┤", horizontal_lines.0, horizontal_lines.1);
 for cmd in commands.iter() {
 println!("{VERTICAL_BAR}{:^w1$}{VERTICAL_BAR} {:<w2$}{VERTICAL_BAR}", cmd.code, cmd.description, w1=max_lengths.0+BUFFER, w2=max_lengths.1+BUFFER-1);
 }
 println!("╰{}┴{}╯", horizontal_lines.0, horizontal_lines.1);
}
struct Command {
 code: char,
 description: String,
}

Source Link

asked Mar 18, 2024 at 7:21

m01010011

asked Mar 18, 2024 at 7:21

m01010011

Rust: Command line menu in ASCII table

Specific areas in which I'd love to get feedback:

Is it good to have the Command struct own the Strings (description field)? Or since these strings aren't really meant to change, should I rather have them as &'static strs?
- I initially used String but then switched to &'static str, and then I saw this SO post and switched back to String.
Within the print_table function, am I complicating the code by having the max_lengths (for two fields of the Command struct) as a tuple instead of using two separate scalar variables?
Also, is there a more idiomatic way of finding the maximum of lengths of a String field in array of structs?
I've seen imports being placed at the top (e.g., use std::cmp::max) before the functions are used (max(1, 2)). I know that this keeps the code terse. However, I'm also a fan of qualified naming (e.g., in Python, it's encouraged to do import math; math.pow(x, y) instead of from math import pow; pow(x, y)). This way, to readers, there's no confusion about the source of a function. What's the general consensus of Rust community? Up to each dev?

fn main() {
 let commands: [Command; 3] = [
 Command {code: '1', description: String::from("Start your instance")},
 Command {code: '2', description: String::from("Stop your instance")},
 Command {code: 'q', description: String::from("Quit")},
 ];
 
 print_table(&commands);
 
 for cmd in commands.iter() {
 match cmd.code {
 '1' => println!("Starting instance"),
 '2' => println!("Stopping instance"),
 'q' => println!("Quitting"),
 _ => println!("Invalid option"),
 }
 }
}
fn print_table(commands: &[Command; 3]) {
 const BUFFER: usize = 2;
 const HEADING: (&str, &str) = ("Code", "Description");
 const VERTICAL_BAR: &str = "│";
 const HORIZONTAL_SEP: &str = "─";
 
 std::process::Command::new("clear").status().unwrap();
 
 let mut max_lengths: (usize, usize) = (0, 0);
 for cmd in commands.iter() {
 max_lengths.0 = std::cmp::max(max_lengths.0, cmd.code.len_utf8());
 max_lengths.1 = std::cmp::max(max_lengths.1, cmd.description.len());
 }
 max_lengths.0 = std::cmp::max(max_lengths.0, HEADING.0.len());
 max_lengths.1 = std::cmp::max(max_lengths.1, HEADING.1.len());
 
 let horizontal_lines: (&str, &str) = (
 &HORIZONTAL_SEP.repeat(max_lengths.0 + BUFFER),
 &HORIZONTAL_SEP.repeat(max_lengths.1 + BUFFER),
 );
 
 println!("╭{}┬{}╮", horizontal_lines.0, horizontal_lines.1);
 println!("{VERTICAL_BAR}{:^w1$}{VERTICAL_BAR} {:^w2$}{VERTICAL_BAR}", HEADING.0, HEADING.1, w1=max_lengths.0+BUFFER, w2=max_lengths.1+BUFFER-1);
 println!("├{}┼{}┤", horizontal_lines.0, horizontal_lines.1);
 for cmd in commands.iter() {
 println!("{VERTICAL_BAR}{:^w1$}{VERTICAL_BAR} {:<w2$}{VERTICAL_BAR}", cmd.code, cmd.description, w1=max_lengths.0+BUFFER, w2=max_lengths.1+BUFFER-1);
 }
 println!("╰{}┴{}╯", horizontal_lines.0, horizontal_lines.1);
}
struct Command {
 code: char,
 description: String,
}
```

lang-rust