use nu_engine::CallExt;
use nu_protocol::ast::Call;
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::{
record, Category, Example, IntoInterruptiblePipelineData, IntoPipelineData, PipelineData,
Record, ShellError, Signature, Span, Spanned, SyntaxShape, Type, Value,
};
#[derive(Clone, Debug)]
enum BeforeOrAfter {
Before(String),
After(String),
}
#[derive(Clone)]
pub struct Move;
impl Command for Move {
fn name(&self) -> &str {
"move"
}
fn usage(&self) -> &str {
"Move columns before or after other columns."
}
fn signature(&self) -> nu_protocol::Signature {
Signature::build("move")
.input_output_types(vec![
(Type::Record(vec![]), Type::Record(vec![])),
(Type::Table(vec![]), Type::Table(vec![])),
])
.rest("columns", SyntaxShape::String, "The columns to move.")
.named(
"after",
SyntaxShape::String,
"the column that will precede the columns moved",
None,
)
.named(
"before",
SyntaxShape::String,
"the column that will be the next after the columns moved",
None,
)
.category(Category::Filters)
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
example: "[[name value index]; [foo a 1] [bar b 2] [baz c 3]] | move index --before name",
description: "Move a column before the first column",
result:
Some(Value::test_list(
vec![
Value::test_record(record! {
"index" => Value::test_int(1),
"name" => Value::test_string("foo"),
"value" => Value::test_string("a"),
}),
Value::test_record(record! {
"index" => Value::test_int(2),
"name" => Value::test_string("bar"),
"value" => Value::test_string("b"),
}),
Value::test_record(record! {
"index" => Value::test_int(3),
"name" => Value::test_string("baz"),
"value" => Value::test_string("c"),
}),
],
))
},
Example {
example: "[[name value index]; [foo a 1] [bar b 2] [baz c 3]] | move value name --after index",
description: "Move multiple columns after the last column and reorder them",
result:
Some(Value::test_list(
vec![
Value::test_record(record! {
"index" => Value::test_int(1),
"value" => Value::test_string("a"),
"name" => Value::test_string("foo"),
}),
Value::test_record(record! {
"index" => Value::test_int(2),
"value" => Value::test_string("b"),
"name" => Value::test_string("bar"),
}),
Value::test_record(record! {
"index" => Value::test_int(3),
"value" => Value::test_string("c"),
"name" => Value::test_string("baz"),
}),
],
))
},
Example {
example: "{ name: foo, value: a, index: 1 } | move name --before index",
description: "Move columns of a record",
result: Some(Value::test_record(record! {
"value" => Value::test_string("a"),
"name" => Value::test_string("foo"),
"index" => Value::test_int(1),
}))
},
]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let columns: Vec<Value> = call.rest(engine_state, stack, 0)?;
let after: Option<Value> = call.get_flag(engine_state, stack, "after")?;
let before: Option<Value> = call.get_flag(engine_state, stack, "before")?;
let before_or_after = match (after, before) {
(Some(v), None) => Spanned {
item: BeforeOrAfter::After(v.as_string()?),
span: v.span(),
},
(None, Some(v)) => Spanned {
item: BeforeOrAfter::Before(v.as_string()?),
span: v.span(),
},
(Some(_), Some(_)) => {
return Err(ShellError::GenericError {
error: "Cannot move columns".into(),
msg: "Use either --after, or --before, not both".into(),
span: Some(call.head),
help: None,
inner: vec![],
})
}
(None, None) => {
return Err(ShellError::GenericError {
error: "Cannot move columns".into(),
msg: "Missing --after or --before flag".into(),
span: Some(call.head),
help: None,
inner: vec![],
})
}
};
let metadata = input.metadata();
let ctrlc = engine_state.ctrlc.clone();
let call = call.clone();
match input {
PipelineData::Value(Value::List { .. }, ..) | PipelineData::ListStream { .. } => {
let res = input.into_iter().map(move |x| match x.as_record() {
Ok(record) => {
match move_record_columns(record, &columns, &before_or_after, call.head) {
Ok(val) => val,
Err(error) => Value::error(error, call.head),
}
}
Err(error) => Value::error(error, call.head),
});
if let Some(md) = metadata {
Ok(res.into_pipeline_data_with_metadata(md, ctrlc))
} else {
Ok(res.into_pipeline_data(ctrlc))
}
}
PipelineData::Value(Value::Record { val, .. }, ..) => {
Ok(
move_record_columns(&val, &columns, &before_or_after, call.head)?
.into_pipeline_data(),
)
}
_ => Err(ShellError::PipelineMismatch {
exp_input_type: "record or table".to_string(),
dst_span: call.head,
src_span: Span::new(call.head.start, call.head.start),
}),
}
}
}
fn move_record_columns(
record: &Record,
columns: &[Value],
before_or_after: &Spanned<BeforeOrAfter>,
span: Span,
) -> Result<Value, ShellError> {
let mut column_idx: Vec<usize> = Vec::with_capacity(columns.len());
match &before_or_after.item {
BeforeOrAfter::After(after) => {
if !record.contains(after) {
return Err(ShellError::GenericError {
error: "Cannot move columns".into(),
msg: "column does not exist".into(),
span: Some(before_or_after.span),
help: None,
inner: vec![],
});
}
}
BeforeOrAfter::Before(before) => {
if !record.contains(before) {
return Err(ShellError::GenericError {
error: "Cannot move columns".into(),
msg: "column does not exist".into(),
span: Some(before_or_after.span),
help: None,
inner: vec![],
});
}
}
}
for column in columns.iter() {
let column_str = column.as_string()?;
if let Some(idx) = record.index_of(&column_str) {
column_idx.push(idx);
} else {
return Err(ShellError::GenericError {
error: "Cannot move columns".into(),
msg: "column does not exist".into(),
span: Some(column.span()),
help: None,
inner: vec![],
});
}
}
let mut out = Record::with_capacity(record.len());
for (i, (inp_col, inp_val)) in record.iter().enumerate() {
match &before_or_after.item {
BeforeOrAfter::After(after) if after == inp_col => {
out.push(inp_col.clone(), inp_val.clone());
for idx in column_idx.iter() {
if let Some((col, val)) = record.get_index(*idx) {
out.push(col.clone(), val.clone());
} else {
return Err(ShellError::NushellFailedSpanned {
msg: "Error indexing input columns".to_string(),
label: "originates from here".to_string(),
span,
});
}
}
}
BeforeOrAfter::Before(before) if before == inp_col => {
for idx in column_idx.iter() {
if let Some((col, val)) = record.get_index(*idx) {
out.push(col.clone(), val.clone());
} else {
return Err(ShellError::NushellFailedSpanned {
msg: "Error indexing input columns".to_string(),
label: "originates from here".to_string(),
span,
});
}
}
out.push(inp_col.clone(), inp_val.clone());
}
_ => {
if !column_idx.contains(&i) {
out.push(inp_col.clone(), inp_val.clone());
}
}
}
}
Ok(Value::record(out, span))
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_examples() {
use crate::test_examples;
test_examples(Move {})
}
}