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use crate::input_handler::{operate, CmdArgument};
use nu_engine::CallExt;
use nu_protocol::ast::Call;
use nu_protocol::ast::CellPath;
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::Category;
use nu_protocol::{Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value};
struct Arguments {
length: Option<i64>,
character: Option<String>,
cell_paths: Option<Vec<CellPath>>,
}
impl CmdArgument for Arguments {
fn take_cell_paths(&mut self) -> Option<Vec<CellPath>> {
self.cell_paths.take()
}
}
#[derive(Clone)]
pub struct SubCommand;
impl Command for SubCommand {
fn name(&self) -> &str {
"str rpad"
}
fn signature(&self) -> Signature {
Signature::build("str rpad")
.input_output_types(vec![(Type::String, Type::String)])
.vectorizes_over_list(true)
.required_named("length", SyntaxShape::Int, "length to pad to", Some('l'))
.required_named(
"character",
SyntaxShape::String,
"character to pad with",
Some('c'),
)
.rest(
"rest",
SyntaxShape::CellPath,
"For a data structure input, pad strings at the given cell paths",
)
.category(Category::Strings)
}
fn usage(&self) -> &str {
"Right-pad a string to a specific length"
}
fn search_terms(&self) -> Vec<&str> {
vec!["append", "truncate", "padding"]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let cell_paths: Vec<CellPath> = call.rest(engine_state, stack, 0)?;
let cell_paths = (!cell_paths.is_empty()).then_some(cell_paths);
let args = Arguments {
length: call.get_flag(engine_state, stack, "length")?,
character: call.get_flag(engine_state, stack, "character")?,
cell_paths,
};
if args.length.expect("this exists") < 0 {
return Err(ShellError::TypeMismatch(
String::from("The length of the string cannot be negative"),
call.head,
));
}
operate(action, args, input, call.head, engine_state.ctrlc.clone())
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Right-pad a string with asterisks until it's 10 characters wide",
example: "'nushell' | str rpad -l 10 -c '*'",
result: Some(Value::test_string("nushell***")),
},
Example {
description: "Right-pad a string with zeroes until it's 10 characters wide",
example: "'123' | str rpad -l 10 -c '0'",
result: Some(Value::test_string("1230000000")),
},
Example {
description: "Use rpad to truncate a string to its first three characters",
example: "'123456789' | str rpad -l 3 -c '0'",
result: Some(Value::test_string("123")),
},
Example {
description: "Use rpad to pad Unicode",
example: "'▉' | str rpad -l 10 -c '▉'",
result: Some(Value::test_string("▉▉▉▉▉▉▉▉▉▉")),
},
]
}
}
fn action(
input: &Value,
Arguments {
character, length, ..
}: &Arguments,
head: Span,
) -> Value {
match &input {
Value::String { val, .. } => match length {
Some(x) => {
let s = *x as usize;
if s < val.len() {
Value::String {
val: val.chars().take(s).collect::<String>(),
span: head,
}
} else {
let mut res = val.to_string();
res += &character.as_ref().expect("we already know this flag needs to exist because the command is type checked before we call the action function").repeat(s - val.chars().count());
Value::String {
val: res,
span: head,
}
}
}
None => Value::Error {
error: ShellError::TypeMismatch(String::from("Length argument is missing"), head),
},
},
Value::Error { .. } => input.clone(),
_ => Value::Error {
error: ShellError::OnlySupportsThisInputType(
"string".into(),
input.get_type().to_string(),
head,
input.expect_span(),
),
},
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_examples() {
use crate::test_examples;
test_examples(SubCommand {})
}
}