69 lines
1.6 KiB
Rust
69 lines
1.6 KiB
Rust
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use std::{borrow::Cow, collections::HashMap};
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use crate::Shell;
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#[derive(Clone, Copy)]
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pub struct Builtin {
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pub name: &'static str,
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pub description: &'static str,
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pub fun: fn(shell: &mut Shell, args: &[Cow<str>]),
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}
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pub static HELP: Builtin = {
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pub fn help(shell: &mut Shell, _args: &[Cow<str>]) {
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println!(
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r"oyster help:
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These are the loaded builtins:"
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);
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for builtin in shell.builtins().iter() {
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println!(" {: <8} {}", builtin.name, builtin.description);
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}
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}
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Builtin {
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name: "help",
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description: "prints help for different builtins",
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fun: help,
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}
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};
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/// Used to register and retrieve builtins.
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#[derive(Default)]
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pub struct BuiltinMap(HashMap<&'static str, Builtin>);
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impl BuiltinMap {
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/// Register a new builtin.
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pub fn add(&mut self, builtin: Builtin) {
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self.0.insert(builtin.name, builtin);
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}
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/// Get a builtin with a given name, if it exists.
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pub fn get(&self, name: &str) -> Option<&Builtin> {
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self.0.get(name)
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}
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/// Returns an iterator over all currently registered builtins.
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pub fn iter(&self) -> impl Iterator<Item = &Builtin> {
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self.0.iter().map(|(_, v)| v)
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}
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/// Add default builtins.
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pub fn add_defaults(&mut self) {
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self.add(HELP);
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}
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}
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impl Shell {
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/// Retrieve builtins.
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pub fn builtins(&self) -> &BuiltinMap {
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&self.builtins
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}
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/// Retrieve builtins, mutably.
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pub fn builtins_mut(&mut self) -> &mut BuiltinMap {
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&mut self.builtins
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}
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}
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