Ian Manske 68fcd71898
Add Value::coerce_str (#11885)
# Description
Following #11851, this PR adds one final conversion function for
`Value`. `Value::coerce_str` takes a `&Value` and converts it to a
`Cow<str>`, creating an owned `String` for types that needed converting.
Otherwise, it returns a borrowed `str` for `String` and `Binary`
`Value`s which avoids a clone/allocation. Where possible, `coerce_str`
and `coerce_into_string` should be used instead of `coerce_string`,
since `coerce_string` always allocates a new `String`.
2024-02-18 17:47:10 +01:00

191 lines
5.8 KiB
Rust

use nu_engine::CallExt;
use nu_protocol::{
ast::Call,
engine::{Command, EngineState, Stack},
Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Type,
Value,
};
use regex::Regex;
#[derive(Clone)]
pub struct SubCommand;
impl Command for SubCommand {
fn name(&self) -> &str {
"split row"
}
fn signature(&self) -> Signature {
Signature::build("split row")
.input_output_types(vec![
(Type::String, Type::List(Box::new(Type::String))),
(
Type::List(Box::new(Type::String)),
(Type::List(Box::new(Type::String))),
),
])
.allow_variants_without_examples(true)
.required(
"separator",
SyntaxShape::String,
"A character or regex that denotes what separates rows.",
)
.named(
"number",
SyntaxShape::Int,
"Split into maximum number of items",
Some('n'),
)
.switch("regex", "use regex syntax for separator", Some('r'))
.category(Category::Strings)
}
fn usage(&self) -> &str {
"Split a string into multiple rows using a separator."
}
fn search_terms(&self) -> Vec<&str> {
vec!["separate", "divide", "regex"]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
split_row(engine_state, stack, call, input)
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Split a string into rows of char",
example: "'abc' | split row ''",
result: Some(Value::list(
vec![
Value::test_string(""),
Value::test_string("a"),
Value::test_string("b"),
Value::test_string("c"),
Value::test_string(""),
],
Span::test_data(),
)),
},
Example {
description: "Split a string into rows by the specified separator",
example: "'a--b--c' | split row '--'",
result: Some(Value::list(
vec![
Value::test_string("a"),
Value::test_string("b"),
Value::test_string("c"),
],
Span::test_data(),
)),
},
Example {
description: "Split a string by '-'",
example: "'-a-b-c-' | split row '-'",
result: Some(Value::list(
vec![
Value::test_string(""),
Value::test_string("a"),
Value::test_string("b"),
Value::test_string("c"),
Value::test_string(""),
],
Span::test_data(),
)),
},
Example {
description: "Split a string by regex",
example: r"'a b c' | split row -r '\s+'",
result: Some(Value::list(
vec![
Value::test_string("a"),
Value::test_string("b"),
Value::test_string("c"),
],
Span::test_data(),
)),
},
]
}
}
fn split_row(
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let name_span = call.head;
let separator: Spanned<String> = call.req(engine_state, stack, 0)?;
let regex = if call.has_flag(engine_state, stack, "regex")? {
Regex::new(&separator.item)
} else {
let escaped = regex::escape(&separator.item);
Regex::new(&escaped)
}
.map_err(|e| ShellError::GenericError {
error: "Error with regular expression".into(),
msg: e.to_string(),
span: Some(separator.span),
help: None,
inner: vec![],
})?;
let max_split: Option<usize> = call.get_flag(engine_state, stack, "number")?;
input.flat_map(
move |x| split_row_helper(&x, &regex, max_split, name_span),
engine_state.ctrlc.clone(),
)
}
fn split_row_helper(v: &Value, regex: &Regex, max_split: Option<usize>, name: Span) -> Vec<Value> {
let span = v.span();
match v {
Value::Error { error, .. } => {
vec![Value::error(*error.clone(), span)]
}
v => {
let v_span = v.span();
if let Ok(s) = v.coerce_str() {
match max_split {
Some(max_split) => regex
.splitn(&s, max_split)
.map(|x: &str| Value::string(x, v_span))
.collect(),
None => regex
.split(&s)
.map(|x: &str| Value::string(x, v_span))
.collect(),
}
} else {
vec![Value::error(
ShellError::PipelineMismatch {
exp_input_type: "string".into(),
dst_span: name,
src_span: v_span,
},
name,
)]
}
}
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_examples() {
use crate::test_examples;
test_examples(SubCommand {})
}
}