nushell/crates/nu-cmd-dataframe/src/dataframe/expressions/is_in.rs
Ian Manske c747ec75c9
Add command_prelude module (#12291)
# 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.
2024-03-26 21:17:30 +00:00

117 lines
3.7 KiB
Rust

use crate::dataframe::values::{Column, NuDataFrame, NuExpression};
use nu_engine::command_prelude::*;
use polars::prelude::{lit, DataType};
#[derive(Clone)]
pub struct ExprIsIn;
impl Command for ExprIsIn {
fn name(&self) -> &str {
"dfr is-in"
}
fn usage(&self) -> &str {
"Creates an is-in expression."
}
fn signature(&self) -> Signature {
Signature::build(self.name())
.required(
"list",
SyntaxShape::List(Box::new(SyntaxShape::Any)),
"List to check if values are in",
)
.input_output_type(
Type::Custom("expression".into()),
Type::Custom("expression".into()),
)
.category(Category::Custom("expression".into()))
}
fn examples(&self) -> Vec<Example> {
vec![Example {
description: "Creates a is-in expression",
example: r#"let df = ([[a b]; [one 1] [two 2] [three 3]] | dfr into-df);
$df | dfr with-column (dfr col a | dfr is-in [one two] | dfr as a_in)"#,
result: Some(
NuDataFrame::try_from_columns(
vec![
Column::new(
"a".to_string(),
vec![
Value::test_string("one"),
Value::test_string("two"),
Value::test_string("three"),
],
),
Column::new(
"b".to_string(),
vec![Value::test_int(1), Value::test_int(2), Value::test_int(3)],
),
Column::new(
"a_in".to_string(),
vec![
Value::test_bool(true),
Value::test_bool(true),
Value::test_bool(false),
],
),
],
None,
)
.expect("simple df for test should not fail")
.into_value(Span::test_data()),
),
}]
}
fn search_terms(&self) -> Vec<&str> {
vec!["check", "contained", "is-contain", "match"]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let list: Vec<Value> = call.req(engine_state, stack, 0)?;
let expr = NuExpression::try_from_pipeline(input, call.head)?;
let values =
NuDataFrame::try_from_columns(vec![Column::new("list".to_string(), list)], None)?;
let list = values.as_series(call.head)?;
if matches!(list.dtype(), DataType::Object(..)) {
return Err(ShellError::IncompatibleParametersSingle {
msg: "Cannot use a mixed list as argument".into(),
span: call.head,
});
}
let expr: NuExpression = expr.into_polars().is_in(lit(list)).into();
Ok(PipelineData::Value(expr.into_value(call.head), None))
}
}
#[cfg(test)]
mod test {
use super::super::super::test_dataframe::test_dataframe;
use super::*;
use crate::dataframe::eager::WithColumn;
use crate::dataframe::expressions::alias::ExprAlias;
use crate::dataframe::expressions::col::ExprCol;
#[test]
fn test_examples() {
test_dataframe(vec![
Box::new(ExprIsIn {}),
Box::new(ExprAlias {}),
Box::new(ExprCol {}),
Box::new(WithColumn {}),
])
}
}