use nu_cmd_base::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::Spanned;
use nu_protocol::{Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value};
use nu_utils::IgnoreCaseExt;
struct Arguments {
substring: String,
cell_paths: Option<Vec<CellPath>>,
case_insensitive: bool,
}
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 starts-with"
}
fn signature(&self) -> Signature {
Signature::build("str starts-with")
.input_output_types(vec![
(Type::String, Type::Bool),
(Type::List(Box::new(Type::String)), Type::List(Box::new(Type::Bool))),
(Type::Table(vec![]), Type::Table(vec![])),
(Type::Record(vec![]), Type::Record(vec![])),
])
.allow_variants_without_examples(true)
.required("string", SyntaxShape::String, "The string to match.")
.rest(
"rest",
SyntaxShape::CellPath,
"For a data structure input, check strings at the given cell paths, and replace with result.",
)
.switch("ignore-case", "search is case insensitive", Some('i'))
.category(Category::Strings)
}
fn usage(&self) -> &str {
"Check if an input starts with a string."
}
fn search_terms(&self) -> Vec<&str> {
vec!["prefix", "match", "find", "search"]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let substring: Spanned<String> = call.req(engine_state, stack, 0)?;
let cell_paths: Vec<CellPath> = call.rest(engine_state, stack, 1)?;
let cell_paths = (!cell_paths.is_empty()).then_some(cell_paths);
let args = Arguments {
substring: substring.item,
cell_paths,
case_insensitive: call.has_flag(engine_state, stack, "ignore-case")?,
};
operate(action, args, input, call.head, engine_state.ctrlc.clone())
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Checks if input string starts with 'my'",
example: "'my_library.rb' | str starts-with 'my'",
result: Some(Value::test_bool(true)),
},
Example {
description: "Checks if input string starts with 'Car'",
example: "'Cargo.toml' | str starts-with 'Car'",
result: Some(Value::test_bool(true)),
},
Example {
description: "Checks if input string starts with '.toml'",
example: "'Cargo.toml' | str starts-with '.toml'",
result: Some(Value::test_bool(false)),
},
Example {
description: "Checks if input string starts with 'cargo', case-insensitive",
example: "'Cargo.toml' | str starts-with --ignore-case 'cargo'",
result: Some(Value::test_bool(true)),
},
]
}
}
fn action(
input: &Value,
Arguments {
substring,
case_insensitive,
..
}: &Arguments,
head: Span,
) -> Value {
match input {
Value::String { val: s, .. } => {
let starts_with = if *case_insensitive {
s.to_folded_case().starts_with(&substring.to_folded_case())
} else {
s.starts_with(substring)
};
Value::bool(starts_with, head)
}
Value::Error { .. } => input.clone(),
_ => Value::error(
ShellError::OnlySupportsThisInputType {
exp_input_type: "string".into(),
wrong_type: input.get_type().to_string(),
dst_span: head,
src_span: input.span(),
},
head,
),
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_examples() {
use crate::test_examples;
test_examples(SubCommand {})
}
}