nushell/src/commands/to_csv.rs

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use crate::commands::WholeStreamCommand;
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use crate::object::{Primitive, Value};
use crate::prelude::*;
use csv::WriterBuilder;
pub struct ToCSV;
#[derive(Deserialize)]
pub struct ToCSVArgs {
headerless: bool,
}
impl WholeStreamCommand for ToCSV {
fn name(&self) -> &str {
"to-csv"
}
fn signature(&self) -> Signature {
Signature::build("to-csv")
.switch("headerless")
}
fn usage(&self) -> &str {
"Convert table into .csv text "
}
fn run(
&self,
args: CommandArgs,
registry: &CommandRegistry,
) -> Result<OutputStream, ShellError> {
args.process(registry, to_csv)?.run()
}
}
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pub fn value_to_csv_value(v: &Value) -> Value {
match v {
Value::Primitive(Primitive::String(s)) => Value::Primitive(Primitive::String(s.clone())),
Value::Primitive(Primitive::Nothing) => Value::Primitive(Primitive::Nothing),
Value::Primitive(Primitive::Boolean(b)) => Value::Primitive(Primitive::Boolean(b.clone())),
Value::Primitive(Primitive::Bytes(b)) => Value::Primitive(Primitive::Bytes(b.clone())),
Value::Primitive(Primitive::Date(d)) => Value::Primitive(Primitive::Date(d.clone())),
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Value::Object(o) => Value::Object(o.clone()),
Value::List(l) => Value::List(l.clone()),
Value::Block(_) => Value::Primitive(Primitive::Nothing),
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_ => Value::Primitive(Primitive::Nothing),
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}
}
fn to_string_helper(v: &Value) -> Result<String, Box<dyn std::error::Error>> {
match v {
Value::Primitive(Primitive::Date(d)) => Ok(d.to_string()),
Value::Primitive(Primitive::Bytes(b)) => Ok(format!("{}", b)),
Value::Primitive(Primitive::Boolean(_)) => Ok(v.as_string()?),
Value::List(_) => return Ok(String::from("[list list]")),
Value::Object(_) => return Ok(String::from("[object]")),
Value::Primitive(Primitive::String(s)) => return Ok(s.to_string()),
_ => return Err("Bad input".into()),
}
}
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pub fn to_string(v: &Value) -> Result<String, Box<dyn std::error::Error>> {
match v {
Value::Object(o) => {
let mut wtr = WriterBuilder::new().from_writer(vec![]);
let mut fields: VecDeque<String> = VecDeque::new();
let mut values: VecDeque<String> = VecDeque::new();
for (k, v) in o.entries.iter() {
fields.push_back(k.clone());
values.push_back(to_string_helper(&v)?);
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}
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wtr.write_record(fields).expect("can not write.");
wtr.write_record(values).expect("can not write.");
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return Ok(String::from_utf8(wtr.into_inner()?)?);
}
_ => return to_string_helper(&v),
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}
}
fn to_csv(
ToCSVArgs { headerless }: ToCSVArgs,
RunnableContext { input, name, .. }: RunnableContext,
) -> Result<OutputStream, ShellError> {
let name_span = name;
let out = input;
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Ok(out
.values
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.map(move |a| match to_string(&value_to_csv_value(&a.item)) {
Ok(x) => {
let converted = if headerless {
x.lines().skip(1).collect()
} else {
x
};
ReturnSuccess::value(
Value::Primitive(Primitive::String(converted)).simple_spanned(name_span),
)
}
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_ => Err(ShellError::labeled_error_with_secondary(
"Expected an object with CSV-compatible structure from pipeline",
"requires CSV-compatible input",
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name_span,
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format!("{} originates from here", a.item.type_name()),
a.span(),
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)),
})
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.to_output_stream())
}