Stefan Holderbach 4b301710d3
Convert more examples and tests to record! macro (#10840)
# Description
Use `record!` macro instead of defining two separate `vec!` for `cols`
and `vals` when appropriate.
This visually aligns the key with the value.
Further more you don't have to deal with the construction of `Record {
cols, vals }` so we can hide the implementation details in the future.

## State

Not covering all possible commands yet, also some tests/examples are
better expressed by creating cols and vals separately.

# User/Developer-Facing Changes
The examples and tests should read more natural. No relevant functional
change

# Bycatch

Where I noticed it I replaced usage of `Value` constructors with
`Span::test_data()` or `Span::unknown()` to the `Value::test_...`
constructors. This should make things more readable and also simplify
changes to the `Span` system in the future.
2023-10-28 14:52:31 +02:00

93 lines
2.4 KiB
Rust

use super::super::values::NuExpression;
use nu_engine::CallExt;
use nu_protocol::{
ast::Call,
engine::{Command, EngineState, Stack},
record, Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
};
#[derive(Clone)]
pub struct ExprAlias;
impl Command for ExprAlias {
fn name(&self) -> &str {
"dfr as"
}
fn usage(&self) -> &str {
"Creates an alias expression."
}
fn signature(&self) -> Signature {
Signature::build(self.name())
.required(
"Alias name",
SyntaxShape::String,
"Alias name for the expression",
)
.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 and alias expression",
example: "dfr col a | dfr as new_a | dfr into-nu",
result: {
let record = Value::test_record(record! {
"expr" => Value::test_record(record! {
"expr" => Value::test_string("column"),
"value" => Value::test_string("a"),
}),
"alias" => Value::test_string("new_a"),
});
Some(record)
},
}]
}
fn search_terms(&self) -> Vec<&str> {
vec!["aka", "abbr", "otherwise"]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let alias: String = call.req(engine_state, stack, 0)?;
let expr = NuExpression::try_from_pipeline(input, call.head)?;
let expr: NuExpression = expr.into_polars().alias(alias.as_str()).into();
Ok(PipelineData::Value(
NuExpression::into_value(expr, call.head),
None,
))
}
}
#[cfg(test)]
mod test {
use super::super::super::test_dataframe::test_dataframe;
use super::*;
use crate::dataframe::eager::ToNu;
use crate::dataframe::expressions::ExprCol;
#[test]
fn test_examples() {
test_dataframe(vec![
Box::new(ExprAlias {}),
Box::new(ExprCol {}),
Box::new(ToNu {}),
])
}
}