nushell/crates/nu-command/src/strings/split/chars.rs
2021-10-09 15:41:39 +13:00

132 lines
3.5 KiB
Rust

use nu_protocol::{
ast::Call,
engine::{Command, EvaluationContext},
Example, IntoValueStream, ShellError, Signature, Span, Type, Value,
};
pub struct SubCommand;
impl Command for SubCommand {
fn name(&self) -> &str {
"split chars"
}
fn signature(&self) -> Signature {
Signature::build("split chars")
}
fn usage(&self) -> &str {
"splits a string's characters into separate rows"
}
fn run(
&self,
_context: &EvaluationContext,
call: &Call,
input: Value,
) -> Result<nu_protocol::Value, nu_protocol::ShellError> {
split_chars(call, input)
}
fn examples(&self) -> Vec<Example> {
vec![Example {
description: "Split the string's characters into separate rows",
example: "echo 'hello' | split chars",
result: Some(vec![
Value::String {
val: "h".into(),
span: Span::unknown(),
},
Value::String {
val: "e".into(),
span: Span::unknown(),
},
Value::String {
val: "l".into(),
span: Span::unknown(),
},
Value::String {
val: "l".into(),
span: Span::unknown(),
},
Value::String {
val: "o".into(),
span: Span::unknown(),
},
]),
}]
}
}
fn split_chars(call: &Call, input: Value) -> Result<nu_protocol::Value, nu_protocol::ShellError> {
let name = call.head;
Ok(match input {
Value::List { vals, span } => Value::List {
vals: vals
.iter()
.flat_map(|x| split_chars_helper(x, name))
.collect(),
span,
},
Value::Stream { stream, span } => Value::Stream {
stream: stream
.flat_map(move |x| split_chars_helper(&x, name))
.into_value_stream(),
span,
},
v => {
let v_span = v.span();
if v.as_string().is_ok() {
Value::List {
vals: split_chars_helper(&v, name),
span: v_span,
}
} else {
Value::Error {
error: ShellError::PipelineMismatch {
expected: Type::String,
expected_span: name,
origin: v.span(),
},
}
}
}
})
}
fn split_chars_helper(v: &Value, name: Span) -> Vec<Value> {
if let Ok(s) = v.as_string() {
let v_span = v.span();
s.chars()
.collect::<Vec<_>>()
.into_iter()
.map(move |x| Value::String {
val: x.to_string(),
span: v_span,
})
.collect()
} else {
vec![Value::Error {
error: ShellError::PipelineMismatch {
expected: Type::String,
expected_span: name,
origin: v.span(),
},
}]
}
}
// #[cfg(test)]
// mod tests {
// use super::ShellError;
// use super::SubCommand;
// #[test]
// fn examples_work_as_expected() -> Result<(), ShellError> {
// use crate::examples::test as test_examples;
// test_examples(SubCommand {})
// }
// }