schala/schala-repl/src/help.rs
2021-10-14 02:08:32 -07:00

86 lines
2.4 KiB
Rust

use std::fmt::Write as FmtWrite;
use crate::command_tree::CommandTree;
use crate::language::ProgrammingLanguageInterface;
use crate::{InterpreterDirectiveOutput, Repl};
use colored::*;
pub fn help<L: ProgrammingLanguageInterface>(
repl: &mut Repl<L>,
arguments: &[&str],
) -> InterpreterDirectiveOutput {
match arguments {
[] => global_help(repl),
commands => {
let dirs = repl.get_directives();
Some(match get_directive_from_commands(commands, &dirs) {
None => format!("Directive `{}` not found", commands.last().unwrap()),
Some(dir) => {
let mut buf = String::new();
let cmd = dir.get_cmd();
let children = dir.get_children();
writeln!(buf, "`{}` - {}", cmd, dir.get_help()).unwrap();
for sub in children.iter() {
writeln!(buf, "\t`{} {}` - {}", cmd, sub.get_cmd(), sub.get_help())
.unwrap();
}
buf
}
})
}
}
}
fn get_directive_from_commands<'a>(
commands: &[&str],
dirs: &'a CommandTree,
) -> Option<&'a CommandTree> {
let mut directive_list = dirs.get_children();
let mut matched_directive = None;
for cmd in commands {
let found = directive_list
.iter()
.find(|directive| directive.get_cmd() == *cmd);
if let Some(dir) = found {
directive_list = dir.get_children();
}
matched_directive = found;
}
matched_directive
}
fn global_help<L: ProgrammingLanguageInterface>(repl: &mut Repl<L>) -> InterpreterDirectiveOutput {
let mut buf = String::new();
writeln!(
buf,
"{} version {}",
"Schala REPL".bright_red().bold(),
crate::VERSION_STRING
)
.unwrap();
writeln!(buf, "-----------------------").unwrap();
for directive in repl.get_directives().get_children() {
writeln!(
buf,
"{}{} - {}",
repl.sigil,
directive.get_cmd(),
directive.get_help()
)
.unwrap();
}
writeln!(buf).unwrap();
writeln!(
buf,
"Language-specific help for {}",
<L as ProgrammingLanguageInterface>::language_name()
)
.unwrap();
writeln!(buf, "-----------------------").unwrap();
Some(buf)
}