nushell/crates/nu-command/src/commands/from_csv.rs
JT f73732bf1e
Move to* and from* to engine-p (#3320)
* WIP

* Finish last batch
2021-04-15 19:43:33 +12:00

109 lines
3.1 KiB
Rust

use crate::commands::from_delimited_data::from_delimited_data;
use crate::prelude::*;
use nu_engine::WholeStreamCommand;
use nu_errors::ShellError;
use nu_protocol::{Primitive, Signature, SyntaxShape, UntaggedValue, Value};
pub struct FromCsv;
impl WholeStreamCommand for FromCsv {
fn name(&self) -> &str {
"from csv"
}
fn signature(&self) -> Signature {
Signature::build("from csv")
.named(
"separator",
SyntaxShape::String,
"a character to separate columns, defaults to ','",
Some('s'),
)
.switch(
"noheaders",
"don't treat the first row as column names",
Some('n'),
)
}
fn usage(&self) -> &str {
"Parse text as .csv and create table."
}
fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
from_csv(args)
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Convert comma-separated data to a table",
example: "open data.txt | from csv",
result: None,
},
Example {
description: "Convert comma-separated data to a table, ignoring headers",
example: "open data.txt | from csv --noheaders",
result: None,
},
Example {
description: "Convert comma-separated data to a table, ignoring headers",
example: "open data.txt | from csv -n",
result: None,
},
Example {
description: "Convert semicolon-separated data to a table",
example: "open data.txt | from csv --separator ';'",
result: None,
},
]
}
}
fn from_csv(args: CommandArgs) -> Result<OutputStream, ShellError> {
let name = args.call_info.name_tag.clone();
let args = args.evaluate_once()?;
let noheaders = args.has_flag("noheaders");
let separator: Option<Value> = args.get_flag("separator")?;
let input = args.input;
let sep = match separator {
Some(Value {
value: UntaggedValue::Primitive(Primitive::String(s)),
tag,
..
}) => {
if s == r"\t" {
'\t'
} else {
let vec_s: Vec<char> = s.chars().collect();
if vec_s.len() != 1 {
return Err(ShellError::labeled_error(
"Expected a single separator char from --separator",
"requires a single character string input",
tag,
));
};
vec_s[0]
}
}
_ => ',',
};
from_delimited_data(noheaders, sep, "CSV", input, name)
}
#[cfg(test)]
mod tests {
use super::FromCsv;
use super::ShellError;
#[test]
fn examples_work_as_expected() -> Result<(), ShellError> {
use crate::examples::test as test_examples;
test_examples(FromCsv {})
}
}