use nu_engine::CallExt;
use nu_protocol::{
ast::Call,
engine::{Command, EngineState, Stack},
Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
};
#[derive(Clone)]
pub struct SubCommand;
impl Command for SubCommand {
fn name(&self) -> &str {
"str expand"
}
fn usage(&self) -> &str {
"Generates all possible combinations defined in brace expansion syntax."
}
fn extra_usage(&self) -> &str {
"This syntax may seem familiar with `glob {A,B}.C`. The difference is glob relies on filesystem, but str expand is not. Inside braces, we put variants. Then basically we're creating all possible outcomes."
}
fn signature(&self) -> Signature {
Signature::build("str expand")
.input_output_types(vec![
(Type::String, Type::List(Box::new(Type::String))),
(
Type::List(Box::new(Type::String)),
Type::List(Box::new(Type::List(Box::new(Type::String)))),
),
])
.switch(
"path",
"Replaces all backslashes with double backslashes, useful for Path.",
None,
)
.allow_variants_without_examples(true)
.category(Category::Strings)
}
fn examples(&self) -> Vec<nu_protocol::Example> {
vec![
Example {
description: "Define a range inside braces to produce a list of string.",
example: "\"{3..5}\" | str expand",
result: Some(Value::list(
vec![
Value::test_string("3"),
Value::test_string("4"),
Value::test_string("5")
],
Span::test_data()
)),
},
Example {
description: "Ignore the next character after the backslash ('\\')",
example: "'A{B\\,,C}' | str expand",
result: Some(Value::list(
vec![
Value::test_string("AB,"),
Value::test_string("AC"),
],
Span::test_data()
)),
},
Example {
description: "Commas that are not inside any braces need to be skipped.",
example: "'Welcome\\, {home,mon ami}!' | str expand",
result: Some(Value::list(
vec![
Value::test_string("Welcome, home!"),
Value::test_string("Welcome, mon ami!"),
],
Span::test_data()
)),
},
Example {
description: "Use double backslashes to add a backslash.",
example: "'A{B\\\\,C}' | str expand",
result: Some(Value::list(
vec![
Value::test_string("AB\\"),
Value::test_string("AC"),
],
Span::test_data()
)),
},
Example {
description: "Export comma separated values inside braces (`{}`) to a string list.",
example: "\"{apple,banana,cherry}\" | str expand",
result: Some(Value::list(
vec![
Value::test_string("apple"),
Value::test_string("banana"),
Value::test_string("cherry")
],
Span::test_data()
)),
},
Example {
description: "If the piped data is path, you may want to use --path flag, or else manually replace the backslashes with double backslashes.",
example: "'C:\\{Users,Windows}' | str expand --path",
result: Some(Value::list(
vec![
Value::test_string("C:\\Users"),
Value::test_string("C:\\Windows"),
],
Span::test_data()
)),
},
Example {
description: "Brace expressions can be used one after another.",
example: "\"A{b,c}D{e,f}G\" | str expand",
result: Some(Value::list(
vec![
Value::test_string("AbDeG"),
Value::test_string("AbDfG"),
Value::test_string("AcDeG"),
Value::test_string("AcDfG"),
],
Span::test_data()
)),
},
Example {
description: "Collection may include an empty item. It can be put at the start of the list.",
example: "\"A{,B,C}\" | str expand",
result: Some(Value::list(
vec![
Value::test_string("A"),
Value::test_string("AB"),
Value::test_string("AC"),
],
Span::test_data()
)),
},
Example {
description: "Empty item can be at the end of the collection.",
example: "\"A{B,C,}\" | str expand",
result: Some(Value::list(
vec![
Value::test_string("AB"),
Value::test_string("AC"),
Value::test_string("A"),
],
Span::test_data()
)),
},
Example {
description: "Empty item can be in the middle of the collection.",
example: "\"A{B,,C}\" | str expand",
result: Some(Value::list(
vec![
Value::test_string("AB"),
Value::test_string("A"),
Value::test_string("AC"),
],
Span::test_data()
)),
},
Example {
description: "Also, it is possible to use one inside another. Here is a real-world example, that creates files:",
example: "\"A{B{1,3},C{2,5}}D\" | str expand",
result: Some(Value::list(
vec![
Value::test_string("AB1D"),
Value::test_string("AB3D"),
Value::test_string("AC2D"),
Value::test_string("AC5D"),
],
Span::test_data()
)),
}
]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let span = call.head;
if matches!(input, PipelineData::Empty) {
return Err(ShellError::PipelineEmpty { dst_span: span });
}
let is_path = call.has_flag(engine_state, stack, "path")?;
input.map(
move |v| {
let value_span = v.span();
match v.coerce_into_string() {
Ok(s) => {
let contents = if is_path { s.replace('\\', "\\\\") } else { s };
str_expand(&contents, span, value_span)
}
Err(_) => Value::error(
ShellError::PipelineMismatch {
exp_input_type: "string".into(),
dst_span: span,
src_span: value_span,
},
span,
),
}
},
engine_state.ctrlc.clone(),
)
}
}
fn str_expand(contents: &str, span: Span, value_span: Span) -> Value {
use bracoxide::{
expand,
parser::{parse, ParsingError},
tokenizer::{tokenize, TokenizationError},
};
match tokenize(contents) {
Ok(tokens) => {
match parse(&tokens) {
Ok(node) => {
match expand(&node) {
Ok(possibilities) => {
Value::list(possibilities.iter().map(|e| Value::string(e,span)).collect::<Vec<Value>>(), span)
},
Err(e) => match e {
bracoxide::ExpansionError::NumConversionFailed(s) => Value::error(
ShellError::GenericError{error: "Number Conversion Failed".into(), msg: format!("Number conversion failed at {s}."), span: Some(value_span), help: Some("Expected number, found text. Range format is `{M..N}`, where M and N are numeric values representing the starting and ending limits.".into()), inner: vec![]},
span,
),
},
}
},
Err(e) => Value::error(
match e {
ParsingError::NoTokens => ShellError::PipelineEmpty { dst_span: value_span },
ParsingError::OBraExpected(s) => ShellError::GenericError{ error: "Opening Brace Expected".into(), msg: format!("Opening brace is expected at {s}."), span: Some(value_span), help: Some("In brace syntax, we use equal amount of opening (`{`) and closing (`}`). Please, take a look at the examples.".into()), inner: vec![]},
ParsingError::CBraExpected(s) => ShellError::GenericError{ error: "Closing Brace Expected".into(), msg: format!("Closing brace is expected at {s}."), span: Some(value_span), help: Some("In brace syntax, we use equal amount of opening (`{`) and closing (`}`). Please, see the examples.".into()), inner: vec![]},
ParsingError::RangeStartLimitExpected(s) => ShellError::GenericError{error: "Range Start Expected".into(), msg: format!("Range start limit is missing, expected at {s}."), span: Some(value_span), help: Some("In brace syntax, Range is defined like `{X..Y}`, where X and Y are a number. X is the start, Y is the end. Please, inspect the examples for more information.".into()), inner: vec![]},
ParsingError::RangeEndLimitExpected(s) => ShellError::GenericError{ error: "Range Start Expected".into(), msg: format!("Range start limit is missing, expected at {s}."),span: Some(value_span), help: Some("In brace syntax, Range is defined like `{X..Y}`, where X and Y are a number. X is the start, Y is the end. Please see the examples, for more information.".into()), inner: vec![]},
ParsingError::ExpectedText(s) => ShellError::GenericError { error: "Expected Text".into(), msg: format!("Expected text at {s}."), span: Some(value_span), help: Some("Texts are only allowed before opening brace (`{`), after closing brace (`}`), or inside `{}`. Please take a look at the examples.".into()), inner: vec![] },
ParsingError::InvalidCommaUsage(s) => ShellError::GenericError { error: "Invalid Comma Usage".into(), msg: format!("Found comma at {s}. Commas are only valid inside collection (`{{X,Y}}`)."),span: Some(value_span), help: Some("To escape comma use backslash `\\,`.".into()), inner: vec![] },
ParsingError::RangeCantHaveText(s) => ShellError::GenericError { error: "Range Can not Have Text".into(), msg: format!("Expecting, brace, number, or range operator, but found text at {s}."), span: Some(value_span), help: Some("Please use the format {M..N} for ranges in brace expansion, where M and N are numeric values representing the starting and ending limits of the sequence, respectively.".into()), inner: vec![]},
ParsingError::ExtraRangeOperator(s) => ShellError::GenericError { error: "Extra Range Operator".into(), msg: format!("Found additional, range operator at {s}."), span: Some(value_span), help: Some("Please, use the format `{M..N}` where M and N are numeric values representing the starting and ending limits of the range.".into()), inner: vec![] },
ParsingError::ExtraCBra(s) => ShellError::GenericError { error: "Extra Closing Brace".into(), msg: format!("Used extra closing brace at {s}."), span: Some(value_span), help: Some("To escape closing brace use backslash, e.g. `\\}`".into()), inner: vec![] },
ParsingError::ExtraOBra(s) => ShellError::GenericError { error: "Extra Opening Brace".into(), msg: format!("Used extra opening brace at {s}."), span: Some(value_span), help: Some("To escape opening brace use backslash, e.g. `\\{`".into()), inner: vec![] },
ParsingError::NothingInBraces(s) => ShellError::GenericError { error: "Nothing In Braces".into(), msg: format!("Nothing found inside braces at {s}."), span: Some(value_span), help: Some("Please provide valid content within the braces. Additionally, you can safely remove it, not needed.".into()), inner: vec![] },
}
,
span,
)
}
},
Err(e) => match e {
TokenizationError::EmptyContent => Value::error(
ShellError::PipelineEmpty { dst_span: value_span },
value_span,
),
TokenizationError::FormatNotSupported => Value::error(
ShellError::GenericError {
error: "Format Not Supported".into(),
msg: "Usage of only `{` or `}`. Brace Expansion syntax, needs to have equal amount of opening (`{`) and closing (`}`)".into(),
span: Some(value_span),
help: Some("In brace expansion syntax, it is important to have an equal number of opening (`{`) and closing (`}`) braces. Please ensure that you provide a balanced pair of braces in your brace expansion pattern.".into()),
inner: vec![]
},
value_span,
),
TokenizationError::NoBraces => Value::error(
ShellError::GenericError { error: "No Braces".into(), msg: "At least one `{}` brace expansion expected.".into(), span: Some(value_span), help: Some("Please, examine the examples.".into()), inner: vec![] },
value_span,
)
},
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn dots() {
assert_eq!(
str_expand("{a.b.c,d}", Span::test_data(), Span::test_data()),
Value::list(
vec![
Value::string(String::from("a.b.c"), Span::test_data(),),
Value::string(String::from("d"), Span::test_data(),)
],
Span::test_data(),
)
);
assert_eq!(
str_expand("{1.2.3,a}", Span::test_data(), Span::test_data()),
Value::list(
vec![
Value::string(String::from("1.2.3"), Span::test_data(),),
Value::string(String::from("a"), Span::test_data(),)
],
Span::test_data(),
)
);
assert_eq!(
str_expand("{a-1.2,b}", Span::test_data(), Span::test_data()),
Value::list(
vec![
Value::string(String::from("a-1.2"), Span::test_data(),),
Value::string(String::from("b"), Span::test_data(),)
],
Span::test_data(),
)
);
}
#[test]
fn test_examples() {
use crate::test_examples;
test_examples(SubCommand {})
}
}