Use NthArgs to better convert to an integer

Using i64 as u64 deserialize isn't implemented yet.
This commit is contained in:
Odin Dutton 2019-08-20 13:12:31 +10:00
parent 82a315f06a
commit 9951691023

View File

@ -3,6 +3,11 @@ use crate::errors::ShellError;
use crate::parser::CommandRegistry; use crate::parser::CommandRegistry;
use crate::prelude::*; use crate::prelude::*;
#[derive(Deserialize)]
struct NthArgs {
position: Tagged<i64>,
}
pub struct Nth; pub struct Nth;
impl WholeStreamCommand for Nth { impl WholeStreamCommand for Nth {
@ -11,7 +16,7 @@ impl WholeStreamCommand for Nth {
args: CommandArgs, args: CommandArgs,
registry: &CommandRegistry, registry: &CommandRegistry,
) -> Result<OutputStream, ShellError> { ) -> Result<OutputStream, ShellError> {
nth(args, registry) args.process(registry, nth)?.run()
} }
fn name(&self) -> &str { fn name(&self) -> &str {
@ -19,27 +24,15 @@ impl WholeStreamCommand for Nth {
} }
fn signature(&self) -> Signature { fn signature(&self) -> Signature {
Signature::build("nth").required("amount", SyntaxType::Literal) Signature::build("nth").optional("amount", SyntaxType::Any)
} }
} }
fn nth(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> { fn nth(
let args = args.evaluate_once(registry)?; NthArgs { position: amount }: NthArgs,
RunnableContext { input, .. }: RunnableContext,
let amount = args.expect_nth(0)?.as_i64(); ) -> Result<OutputStream, ShellError> {
let amount = match amount {
Ok(o) => o,
Err(_) => {
return Err(ShellError::labeled_error(
"Value is not a number",
"expected integer",
args.expect_nth(0)?.span(),
))
}
};
Ok(OutputStream::from_input( Ok(OutputStream::from_input(
args.input.values.skip(amount as u64).take(1), input.values.skip(amount.item as u64).take(1),
)) ))
} }