forked from extern/nushell
e4226def16
This commit extracts five new crates:
- nu-source, which contains the core source-code handling logic in Nu,
including Text, Span, and also the pretty.rs-based debug logic
- nu-parser, which is the parser and expander logic
- nu-protocol, which is the bulk of the types and basic conveniences
used by plugins
- nu-errors, which contains ShellError, ParseError and error handling
conveniences
- nu-textview, which is the textview plugin extracted into a crate
One of the major consequences of this refactor is that it's no longer
possible to `impl X for Spanned<Y>` outside of the `nu-source` crate, so
a lot of types became more concrete (Value became a concrete type
instead of Spanned<Value>, for example).
This also turned a number of inherent methods in the main nu crate into
plain functions (impl Value {} became a bunch of functions in the
`value` namespace in `crate::data::value`).
62 lines
1.7 KiB
Rust
62 lines
1.7 KiB
Rust
use nu::{serve_plugin, Plugin};
|
|
use nu_errors::{CoerceInto, ShellError};
|
|
use nu_protocol::{
|
|
CallInfo, Primitive, ReturnSuccess, ReturnValue, Signature, SyntaxShape, UntaggedValue, Value,
|
|
};
|
|
use nu_source::TaggedItem;
|
|
|
|
struct Skip {
|
|
skip_amount: i64,
|
|
}
|
|
|
|
impl Skip {
|
|
fn new() -> Skip {
|
|
Skip { skip_amount: 0 }
|
|
}
|
|
}
|
|
|
|
impl Plugin for Skip {
|
|
fn config(&mut self) -> Result<Signature, ShellError> {
|
|
Ok(Signature::build("skip")
|
|
.desc("Skip a number of rows")
|
|
.rest(SyntaxShape::Number, "the number of rows to skip")
|
|
.filter())
|
|
}
|
|
fn begin_filter(&mut self, call_info: CallInfo) -> Result<Vec<ReturnValue>, ShellError> {
|
|
if let Some(args) = call_info.args.positional {
|
|
for arg in args {
|
|
match arg {
|
|
Value {
|
|
value: UntaggedValue::Primitive(Primitive::Int(i)),
|
|
tag,
|
|
} => {
|
|
self.skip_amount = i.tagged(tag).coerce_into("converting for skip")?;
|
|
}
|
|
_ => {
|
|
return Err(ShellError::labeled_error(
|
|
"Unrecognized type in params",
|
|
"expected an integer",
|
|
arg.tag(),
|
|
))
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
Ok(vec![])
|
|
}
|
|
|
|
fn filter(&mut self, input: Value) -> Result<Vec<ReturnValue>, ShellError> {
|
|
if self.skip_amount == 0 {
|
|
Ok(vec![ReturnSuccess::value(input)])
|
|
} else {
|
|
self.skip_amount -= 1;
|
|
Ok(vec![])
|
|
}
|
|
}
|
|
}
|
|
|
|
fn main() {
|
|
serve_plugin(&mut Skip::new());
|
|
}
|