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4b301710d3
# 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.
73 lines
1.9 KiB
Rust
73 lines
1.9 KiB
Rust
use crate::dataframe::values::NuExpression;
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use nu_engine::CallExt;
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use nu_protocol::{
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ast::Call,
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engine::{Command, EngineState, Stack},
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record, Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
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};
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use polars::prelude::col;
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#[derive(Clone)]
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pub struct ExprCol;
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impl Command for ExprCol {
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fn name(&self) -> &str {
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"dfr col"
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}
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fn usage(&self) -> &str {
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"Creates a named column expression."
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}
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fn signature(&self) -> Signature {
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Signature::build(self.name())
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.required(
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"column name",
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SyntaxShape::String,
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"Name of column to be used",
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)
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.input_output_type(Type::Any, Type::Custom("expression".into()))
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.category(Category::Custom("expression".into()))
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}
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fn examples(&self) -> Vec<Example> {
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vec![Example {
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description: "Creates a named column expression and converts it to a nu object",
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example: "dfr col a | dfr into-nu",
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result: Some(Value::test_record(record! {
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"expr" => Value::test_string("column"),
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"value" => Value::test_string("a"),
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})),
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}]
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}
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fn search_terms(&self) -> Vec<&str> {
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vec!["create"]
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}
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fn run(
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&self,
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engine_state: &EngineState,
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stack: &mut Stack,
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call: &Call,
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_input: PipelineData,
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) -> Result<PipelineData, ShellError> {
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let name: String = call.req(engine_state, stack, 0)?;
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let expr: NuExpression = col(name.as_str()).into();
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Ok(PipelineData::Value(expr.into_value(call.head), None))
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}
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}
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#[cfg(test)]
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mod test {
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use super::super::super::test_dataframe::test_dataframe;
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use super::*;
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use crate::dataframe::eager::ToNu;
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#[test]
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fn test_examples() {
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test_dataframe(vec![Box::new(ExprCol {}), Box::new(ToNu {})])
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}
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}
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