c747ec75c9
# Description
When implementing a `Command`, one must also import all the types
present in the function signatures for `Command`. This makes it so that
we often import the same set of types in each command implementation
file. E.g., something like this:
```rust
use nu_protocol::ast::Call;
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::{
record, Category, Example, IntoInterruptiblePipelineData, IntoPipelineData, PipelineData,
ShellError, Signature, Span, Type, Value,
};
```
This PR adds the `nu_engine::command_prelude` module which contains the
necessary and commonly used types to implement a `Command`:
```rust
// command_prelude.rs
pub use crate::CallExt;
pub use nu_protocol::{
ast::{Call, CellPath},
engine::{Command, EngineState, Stack},
record, Category, Example, IntoInterruptiblePipelineData, IntoPipelineData, IntoSpanned,
PipelineData, Record, ShellError, Signature, Span, Spanned, SyntaxShape, Type, Value,
};
```
This should reduce the boilerplate needed to implement a command and
also gives us a place to track the breadth of the `Command` API. I tried
to be conservative with what went into the prelude modules, since it
might be hard/annoying to remove items from the prelude in the future.
Let me know if something should be included or excluded.
39 lines
953 B
Rust
39 lines
953 B
Rust
use nu_engine::command_prelude::*;
|
|
|
|
#[derive(Clone)]
|
|
pub struct HistorySession;
|
|
|
|
impl Command for HistorySession {
|
|
fn name(&self) -> &str {
|
|
"history session"
|
|
}
|
|
|
|
fn usage(&self) -> &str {
|
|
"Get the command history session."
|
|
}
|
|
|
|
fn signature(&self) -> nu_protocol::Signature {
|
|
Signature::build("history session")
|
|
.category(Category::History)
|
|
.input_output_types(vec![(Type::Nothing, Type::Int)])
|
|
}
|
|
|
|
fn examples(&self) -> Vec<Example> {
|
|
vec![Example {
|
|
example: "history session",
|
|
description: "Get current history session",
|
|
result: None,
|
|
}]
|
|
}
|
|
|
|
fn run(
|
|
&self,
|
|
engine_state: &EngineState,
|
|
_stack: &mut Stack,
|
|
call: &Call,
|
|
_input: PipelineData,
|
|
) -> Result<PipelineData, ShellError> {
|
|
Ok(Value::int(engine_state.history_session_id, call.head).into_pipeline_data())
|
|
}
|
|
}
|