use nu_engine::{command_prelude::*, get_eval_block, EvalBlockFn};
use nu_protocol::{
ast::{Block, PathMember},
engine::Closure,
FromValue,
};
#[derive(Clone)]
pub struct Insert;
impl Command for Insert {
fn name(&self) -> &str {
"insert"
}
fn signature(&self) -> Signature {
Signature::build("insert")
.input_output_types(vec![
(Type::Record(vec![]), Type::Record(vec![])),
(Type::Table(vec![]), Type::Table(vec![])),
(
Type::List(Box::new(Type::Any)),
Type::List(Box::new(Type::Any)),
),
])
.required(
"field",
SyntaxShape::CellPath,
"The name of the column to insert.",
)
.required(
"new value",
SyntaxShape::Any,
"The new value to give the cell(s).",
)
.allow_variants_without_examples(true)
.category(Category::Filters)
}
fn usage(&self) -> &str {
"Insert a new column, using an expression or closure to create each row's values."
}
fn extra_usage(&self) -> &str {
"When inserting a column, the closure will be run for each row, and the current row will be passed as the first argument.
When inserting into a specific index, the closure will instead get the current value at the index or null if inserting at the end of a list/table."
}
fn search_terms(&self) -> Vec<&str> {
vec!["add"]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
insert(engine_state, stack, call, input)
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Insert a new entry into a single record",
example: "{'name': 'nu', 'stars': 5} | insert alias 'Nushell'",
result: Some(Value::test_record(record! {
"name" => Value::test_string("nu"),
"stars" => Value::test_int(5),
"alias" => Value::test_string("Nushell"),
})),
},
Example {
description: "Insert a new column into a table, populating all rows",
example: "[[project, lang]; ['Nushell', 'Rust']] | insert type 'shell'",
result: Some(Value::test_list(vec![Value::test_record(record! {
"project" => Value::test_string("Nushell"),
"lang" => Value::test_string("Rust"),
"type" => Value::test_string("shell"),
})])),
},
Example {
description: "Insert a new column with values computed based off the other columns",
example: "[[foo]; [7] [8] [9]] | insert bar {|row| $row.foo * 2 }",
result: Some(Value::test_list(vec![
Value::test_record(record! {
"foo" => Value::test_int(7),
"bar" => Value::test_int(14),
}),
Value::test_record(record! {
"foo" => Value::test_int(8),
"bar" => Value::test_int(16),
}),
Value::test_record(record! {
"foo" => Value::test_int(9),
"bar" => Value::test_int(18),
}),
])),
},
Example {
description: "Insert a new value into a list at an index",
example: "[1 2 4] | insert 2 3",
result: Some(Value::test_list(vec![
Value::test_int(1),
Value::test_int(2),
Value::test_int(3),
Value::test_int(4),
])),
},
Example {
description: "Insert a new value at the end of a list",
example: "[1 2 3] | insert 3 4",
result: Some(Value::test_list(vec![
Value::test_int(1),
Value::test_int(2),
Value::test_int(3),
Value::test_int(4),
])),
},
]
}
}
fn insert(
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let span = call.head;
let cell_path: CellPath = call.req(engine_state, stack, 0)?;
let replacement: Value = call.req(engine_state, stack, 1)?;
let ctrlc = engine_state.ctrlc.clone();
let eval_block = get_eval_block(engine_state);
match input {
PipelineData::Value(mut value, metadata) => {
if replacement.coerce_block().is_ok() {
match (cell_path.members.first(), &mut value) {
(Some(PathMember::String { .. }), Value::List { vals, .. }) => {
let span = replacement.span();
let capture_block = Closure::from_value(replacement)?;
let block = engine_state.get_block(capture_block.block_id);
let stack = stack.captures_to_stack(capture_block.captures.clone());
for val in vals {
let mut stack = stack.clone();
insert_value_by_closure(
val,
span,
engine_state,
&mut stack,
block,
&cell_path.members,
false,
eval_block,
)?;
}
}
(first, _) => {
insert_single_value_by_closure(
&mut value,
replacement,
engine_state,
stack,
&cell_path.members,
matches!(first, Some(PathMember::Int { .. })),
eval_block,
)?;
}
}
} else {
value.insert_data_at_cell_path(&cell_path.members, replacement, span)?;
}
Ok(value.into_pipeline_data_with_metadata(metadata))
}
PipelineData::ListStream(mut stream, metadata) => {
if let Some((
&PathMember::Int {
val,
span: path_span,
..
},
path,
)) = cell_path.members.split_first()
{
let mut pre_elems = vec![];
for idx in 0..val {
if let Some(v) = stream.next() {
pre_elems.push(v);
} else {
return Err(ShellError::InsertAfterNextFreeIndex {
available_idx: idx,
span: path_span,
});
}
}
if path.is_empty() {
if replacement.coerce_block().is_ok() {
let span = replacement.span();
let value = stream.next();
let end_of_stream = value.is_none();
let value = value.unwrap_or(Value::nothing(span));
let capture_block = Closure::from_value(replacement)?;
let block = engine_state.get_block(capture_block.block_id);
let mut stack = stack.captures_to_stack(capture_block.captures);
if let Some(var) = block.signature.get_positional(0) {
if let Some(var_id) = &var.var_id {
stack.add_var(*var_id, value.clone())
}
}
let output = eval_block(
engine_state,
&mut stack,
block,
value.clone().into_pipeline_data(),
)?;
pre_elems.push(output.into_value(span));
if !end_of_stream {
pre_elems.push(value);
}
} else {
pre_elems.push(replacement);
}
} else if let Some(mut value) = stream.next() {
if replacement.coerce_block().is_ok() {
insert_single_value_by_closure(
&mut value,
replacement,
engine_state,
stack,
path,
true,
eval_block,
)?;
} else {
value.insert_data_at_cell_path(path, replacement, span)?;
}
pre_elems.push(value)
} else {
return Err(ShellError::AccessBeyondEnd {
max_idx: pre_elems.len() - 1,
span: path_span,
});
}
Ok(pre_elems
.into_iter()
.chain(stream)
.into_pipeline_data_with_metadata(metadata, ctrlc))
} else if replacement.coerce_block().is_ok() {
let engine_state = engine_state.clone();
let replacement_span = replacement.span();
let capture_block = Closure::from_value(replacement)?;
let block = engine_state.get_block(capture_block.block_id).clone();
let stack = stack.captures_to_stack(capture_block.captures.clone());
Ok(stream
.map(move |mut input| {
let mut stack = stack.clone();
let err = insert_value_by_closure(
&mut input,
replacement_span,
&engine_state,
&mut stack,
&block,
&cell_path.members,
false,
eval_block,
);
if let Err(e) = err {
Value::error(e, span)
} else {
input
}
})
.into_pipeline_data_with_metadata(metadata, ctrlc))
} else {
Ok(stream
.map(move |mut input| {
if let Err(e) = input.insert_data_at_cell_path(
&cell_path.members,
replacement.clone(),
span,
) {
Value::error(e, span)
} else {
input
}
})
.into_pipeline_data_with_metadata(metadata, ctrlc))
}
}
PipelineData::Empty => Err(ShellError::IncompatiblePathAccess {
type_name: "empty pipeline".to_string(),
span,
}),
PipelineData::ExternalStream { .. } => Err(ShellError::IncompatiblePathAccess {
type_name: "external stream".to_string(),
span,
}),
}
}
#[allow(clippy::too_many_arguments)]
fn insert_value_by_closure(
value: &mut Value,
span: Span,
engine_state: &EngineState,
stack: &mut Stack,
block: &Block,
cell_path: &[PathMember],
first_path_member_int: bool,
eval_block_fn: EvalBlockFn,
) -> Result<(), ShellError> {
let input = if first_path_member_int {
value
.clone()
.follow_cell_path(cell_path, false)
.unwrap_or(Value::nothing(span))
} else {
value.clone()
};
if let Some(var) = block.signature.get_positional(0) {
if let Some(var_id) = var.var_id {
stack.add_var(var_id, input.clone());
}
}
let output = eval_block_fn(engine_state, stack, block, input.into_pipeline_data())?;
value.insert_data_at_cell_path(cell_path, output.into_value(span), span)
}
#[allow(clippy::too_many_arguments)]
fn insert_single_value_by_closure(
value: &mut Value,
replacement: Value,
engine_state: &EngineState,
stack: &mut Stack,
cell_path: &[PathMember],
first_path_member_int: bool,
eval_block_fn: EvalBlockFn,
) -> Result<(), ShellError> {
let span = replacement.span();
let capture_block = Closure::from_value(replacement)?;
let block = engine_state.get_block(capture_block.block_id);
let mut stack = stack.captures_to_stack(capture_block.captures);
insert_value_by_closure(
value,
span,
engine_state,
&mut stack,
block,
cell_path,
first_path_member_int,
eval_block_fn,
)
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_examples() {
use crate::test_examples;
test_examples(Insert {})
}
}