nushell/crates/nu-command/src/formats/to/csv.rs
2023-10-08 19:07:09 +02:00

117 lines
3.4 KiB
Rust

use crate::formats::to::delimited::to_delimited_data;
use nu_engine::CallExt;
use nu_protocol::ast::Call;
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::{
Category, Config, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape,
Type, Value,
};
#[derive(Clone)]
pub struct ToCsv;
impl Command for ToCsv {
fn name(&self) -> &str {
"to csv"
}
fn signature(&self) -> Signature {
Signature::build("to csv")
.input_output_types(vec![
(Type::Record(vec![]), Type::String),
(Type::Table(vec![]), Type::String),
])
.named(
"separator",
SyntaxShape::String,
"a character to separate columns, defaults to ','",
Some('s'),
)
.switch(
"noheaders",
"do not output the columns names as the first row",
Some('n'),
)
.category(Category::Formats)
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Outputs an CSV string representing the contents of this table",
example: "[[foo bar]; [1 2]] | to csv",
result: Some(Value::test_string("foo,bar\n1,2\n")),
},
Example {
description: "Outputs an CSV string representing the contents of this table",
example: "[[foo bar]; [1 2]] | to csv --separator ';' ",
result: Some(Value::test_string("foo;bar\n1;2\n")),
},
Example {
description: "Outputs an CSV string representing the contents of this record",
example: "{a: 1 b: 2} | to csv",
result: Some(Value::test_string("a,b\n1,2\n")),
},
]
}
fn usage(&self) -> &str {
"Convert table into .csv text ."
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let head = call.head;
let noheaders = call.has_flag("noheaders");
let separator: Option<Spanned<String>> = call.get_flag(engine_state, stack, "separator")?;
let config = engine_state.get_config();
to_csv(input, noheaders, separator, head, config)
}
}
fn to_csv(
input: PipelineData,
noheaders: bool,
separator: Option<Spanned<String>>,
head: Span,
config: &Config,
) -> Result<PipelineData, ShellError> {
let sep = match separator {
Some(Spanned { item: s, span, .. }) => {
if s == r"\t" {
'\t'
} else {
let vec_s: Vec<char> = s.chars().collect();
if vec_s.len() != 1 {
return Err(ShellError::TypeMismatch {
err_message: "Expected a single separator char from --separator"
.to_string(),
span,
});
};
vec_s[0]
}
}
_ => ',',
};
to_delimited_data(noheaders, sep, "CSV", input, head, config)
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_examples() {
use crate::test_examples;
test_examples(ToCsv {})
}
}