nushell/src/commands/from_csv.rs
Yehuda Katz f70c6d5d48 Extract nu_source into a crate
This commit extracts Tag, Span, Text, as well as source-related debug
facilities into a new crate called nu_source.

This change is much bigger than one might have expected because the
previous code relied heavily on implementing inherent methods on
`Tagged<T>` and `Spanned<T>`, which is no longer possible.

As a result, this change creates more concrete types instead of using
`Tagged<T>`. One notable example: Tagged<Value> became Value, and Value
became UntaggedValue.

This change clarifies the intent of the code in many places, but it does
make it a big change.
2019-11-25 07:37:33 -08:00

74 lines
1.9 KiB
Rust

use crate::commands::from_delimited_data::from_delimited_data;
use crate::commands::WholeStreamCommand;
use crate::data::{Primitive, Value};
use crate::prelude::*;
pub struct FromCSV;
#[derive(Deserialize)]
pub struct FromCSVArgs {
headerless: bool,
separator: Option<Value>,
}
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 ','",
)
.switch("headerless", "don't treat the first row as column names")
}
fn usage(&self) -> &str {
"Parse text as .csv and create table."
}
fn run(
&self,
args: CommandArgs,
registry: &CommandRegistry,
) -> Result<OutputStream, ShellError> {
args.process(registry, from_csv)?.run()
}
}
fn from_csv(
FromCSVArgs {
headerless,
separator,
}: FromCSVArgs,
runnable_context: RunnableContext,
) -> Result<OutputStream, ShellError> {
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(headerless, sep, "CSV", runnable_context)
}