Files
nushell/crates/nu-cmd-dataframe/src/dataframe/series/string/strftime.rs
JT 9068093081 Improve type hovers (#9515)
# Description

This PR does a few things to help improve type hovers and, in the
process, fixes a few outstanding issues in the type system. Here's a
list of the changes:

* `for` now will try to infer the type of the iteration variable based
on the expression it's given. This fixes things like `for x in [1, 2, 3]
{ }` where `x` now properly gets the int type.
* Removed old input/output type fields from the signature, focuses on
the vec of signatures. Updated a bunch of dataframe commands that hadn't
moved over. This helps tie things together a bit better
* Fixed inference of types from subexpressions to use the last
expression in the block
* Fixed handling of explicit types in `let` and `mut` calls, so we now
respect that as the authoritative type

I also tried to add `def` input/output type inference, but unfortunately
we only know the predecl types universally, which means we won't have
enough information to properly know what the types of the custom
commands are.

# User-Facing Changes

Script typechecking will get tighter in some cases
Hovers should be more accurate in some cases that previously resorted to
any.

# Tests + Formatting
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---------

Co-authored-by: Darren Schroeder <343840+fdncred@users.noreply.github.com>
2023-06-29 05:19:48 +12:00

112 lines
3.2 KiB
Rust

use super::super::super::values::{Column, NuDataFrame};
use nu_engine::CallExt;
use nu_protocol::{
ast::Call,
engine::{Command, EngineState, Stack},
Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
};
use polars::prelude::IntoSeries;
#[derive(Clone)]
pub struct StrFTime;
impl Command for StrFTime {
fn name(&self) -> &str {
"dfr strftime"
}
fn usage(&self) -> &str {
"Formats date based on string rule."
}
fn signature(&self) -> Signature {
Signature::build(self.name())
.required("fmt", SyntaxShape::String, "Format rule")
.input_output_type(
Type::Custom("dataframe".into()),
Type::Custom("dataframe".into()),
)
.category(Category::Custom("dataframe".into()))
}
fn examples(&self) -> Vec<Example> {
vec![Example {
description: "Formats date",
example: r#"let dt = ('2020-08-04T16:39:18+00:00' | into datetime -z 'UTC');
let df = ([$dt $dt] | dfr into-df);
$df | dfr strftime "%Y/%m/%d""#,
result: Some(
NuDataFrame::try_from_columns(vec![Column::new(
"0".to_string(),
vec![
Value::test_string("2020/08/04"),
Value::test_string("2020/08/04"),
],
)])
.expect("simple df for test should not fail")
.into_value(Span::test_data()),
),
}]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
command(engine_state, stack, call, input)
}
}
fn command(
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let fmt: String = call.req(engine_state, stack, 0)?;
let df = NuDataFrame::try_from_pipeline(input, call.head)?;
let series = df.as_series(call.head)?;
let casted = series.datetime().map_err(|e| {
ShellError::GenericError(
"Error casting to date".into(),
e.to_string(),
Some(call.head),
Some("The str-slice command can only be used with string columns".into()),
Vec::new(),
)
})?;
let res = casted
.strftime(&fmt)
.map_err(|e| {
ShellError::GenericError(
"Error formatting datetime".into(),
e.to_string(),
Some(call.head),
None,
Vec::new(),
)
})?
.into_series();
NuDataFrame::try_from_series(vec![res.into_series()], call.head)
.map(|df| PipelineData::Value(NuDataFrame::into_value(df, call.head), None))
}
#[cfg(explore_refactor_IntoDatetime)]
mod test {
use super::super::super::super::super::IntoDatetime;
use super::super::super::super::test_dataframe::test_dataframe;
use super::*;
#[test]
fn test_examples() {
test_dataframe(vec![Box::new(StrFTime {}), Box::new(IntoDatetime {})])
}
}