use nu_engine::command_prelude::*;
use nu_protocol::ast::{Assignment, Bits, Boolean, Comparison, Math, Operator};
#[derive(Clone)]
pub struct HelpOperators;
impl Command for HelpOperators {
fn name(&self) -> &str {
"help operators"
}
fn description(&self) -> &str {
"Show help on nushell operators."
}
fn signature(&self) -> Signature {
Signature::build("help operators")
.category(Category::Core)
.input_output_types(vec![(Type::Nothing, Type::table())])
.allow_variants_without_examples(true)
}
fn run(
&self,
_engine_state: &EngineState,
_stack: &mut Stack,
call: &Call,
_input: PipelineData,
) -> Result<PipelineData, ShellError> {
let head = call.head;
let mut operators = [
Operator::Assignment(Assignment::Assign),
Operator::Assignment(Assignment::AddAssign),
Operator::Assignment(Assignment::SubtractAssign),
Operator::Assignment(Assignment::MultiplyAssign),
Operator::Assignment(Assignment::DivideAssign),
Operator::Assignment(Assignment::ConcatenateAssign),
Operator::Comparison(Comparison::Equal),
Operator::Comparison(Comparison::NotEqual),
Operator::Comparison(Comparison::LessThan),
Operator::Comparison(Comparison::GreaterThan),
Operator::Comparison(Comparison::LessThanOrEqual),
Operator::Comparison(Comparison::GreaterThanOrEqual),
Operator::Comparison(Comparison::RegexMatch),
Operator::Comparison(Comparison::NotRegexMatch),
Operator::Comparison(Comparison::In),
Operator::Comparison(Comparison::NotIn),
Operator::Comparison(Comparison::Has),
Operator::Comparison(Comparison::NotHas),
Operator::Comparison(Comparison::StartsWith),
Operator::Comparison(Comparison::EndsWith),
Operator::Math(Math::Add),
Operator::Math(Math::Subtract),
Operator::Math(Math::Multiply),
Operator::Math(Math::Divide),
Operator::Math(Math::FloorDivide),
Operator::Math(Math::Modulo),
Operator::Math(Math::Pow),
Operator::Math(Math::Concatenate),
Operator::Bits(Bits::BitOr),
Operator::Bits(Bits::BitXor),
Operator::Bits(Bits::BitAnd),
Operator::Bits(Bits::ShiftLeft),
Operator::Bits(Bits::ShiftRight),
Operator::Boolean(Boolean::Or),
Operator::Boolean(Boolean::Xor),
Operator::Boolean(Boolean::And),
]
.into_iter()
.map(|op| {
if op == Operator::Comparison(Comparison::RegexMatch) {
Value::record(
record! {
"type" => Value::string(op_type(&op), head),
"operator" => Value::string("=~, like", head),
"name" => Value::string(name(&op), head),
"description" => Value::string(description(&op), head),
"precedence" => Value::int(op.precedence().into(), head),
},
head,
)
} else if op == Operator::Comparison(Comparison::NotRegexMatch) {
Value::record(
record! {
"type" => Value::string(op_type(&op), head),
"operator" => Value::string("!~, not-like", head),
"name" => Value::string(name(&op), head),
"description" => Value::string(description(&op), head),
"precedence" => Value::int(op.precedence().into(), head),
},
head,
)
} else {
Value::record(
record! {
"type" => Value::string(op_type(&op), head),
"operator" => Value::string(op.to_string(), head),
"name" => Value::string(name(&op), head),
"description" => Value::string(description(&op), head),
"precedence" => Value::int(op.precedence().into(), head),
},
head,
)
}
})
.collect::<Vec<_>>();
operators.push(Value::record(
record! {
"type" => Value::string("Boolean", head),
"operator" => Value::string("not", head),
"name" => Value::string("Not", head),
"description" => Value::string("Negates a value or expression.", head),
"precedence" => Value::int(55, head),
},
head,
));
Ok(Value::list(operators, head).into_pipeline_data())
}
}
fn op_type(operator: &Operator) -> &'static str {
match operator {
Operator::Comparison(_) => "Comparison",
Operator::Math(_) => "Math",
Operator::Boolean(_) => "Boolean",
Operator::Bits(_) => "Bitwise",
Operator::Assignment(_) => "Assignment",
}
}
fn name(operator: &Operator) -> String {
match operator {
Operator::Comparison(op) => format!("{op:?}"),
Operator::Math(op) => format!("{op:?}"),
Operator::Boolean(op) => format!("{op:?}"),
Operator::Bits(op) => format!("{op:?}"),
Operator::Assignment(op) => format!("{op:?}"),
}
}
fn description(operator: &Operator) -> &'static str {
match operator {
Operator::Comparison(Comparison::Equal) => "Checks if two values are equal.",
Operator::Comparison(Comparison::NotEqual) => "Checks if two values are not equal.",
Operator::Comparison(Comparison::LessThan) => "Checks if a value is less than another.",
Operator::Comparison(Comparison::GreaterThan) => {
"Checks if a value is greater than another."
}
Operator::Comparison(Comparison::LessThanOrEqual) => {
"Checks if a value is less than or equal to another."
}
Operator::Comparison(Comparison::GreaterThanOrEqual) => {
"Checks if a value is greater than or equal to another."
}
Operator::Comparison(Comparison::RegexMatch) => {
"Checks if a value matches a regular expression."
}
Operator::Comparison(Comparison::NotRegexMatch) => {
"Checks if a value does not match a regular expression."
}
Operator::Comparison(Comparison::In) => {
"Checks if a value is in a list, is part of a string, or is a key in a record."
}
Operator::Comparison(Comparison::NotIn) => {
"Checks if a value is not in a list, is not part of a string, or is not a key in a record."
}
Operator::Comparison(Comparison::Has) => {
"Checks if a list contains a value, a string contains another, or if a record has a key."
}
Operator::Comparison(Comparison::NotHas) => {
"Checks if a list does not contain a value, a string does not contain another, or if a record does not have a key."
}
Operator::Comparison(Comparison::StartsWith) => "Checks if a string starts with another.",
Operator::Comparison(Comparison::EndsWith) => "Checks if a string ends with another.",
Operator::Math(Math::Add) => "Adds two values.",
Operator::Math(Math::Subtract) => "Subtracts two values.",
Operator::Math(Math::Multiply) => "Multiplies two values.",
Operator::Math(Math::Divide) => "Divides two values.",
Operator::Math(Math::FloorDivide) => "Divides two values and floors the result.",
Operator::Math(Math::Modulo) => "Divides two values and returns the remainder.",
Operator::Math(Math::Pow) => "Raises one value to the power of another.",
Operator::Math(Math::Concatenate) => {
"Concatenates two lists, two strings, or two binary values."
}
Operator::Boolean(Boolean::Or) => "Checks if either value is true.",
Operator::Boolean(Boolean::Xor) => "Checks if one value is true and the other is false.",
Operator::Boolean(Boolean::And) => "Checks if both values are true.",
Operator::Bits(Bits::BitOr) => "Performs a bitwise OR on two values.",
Operator::Bits(Bits::BitXor) => "Performs a bitwise XOR on two values.",
Operator::Bits(Bits::BitAnd) => "Performs a bitwise AND on two values.",
Operator::Bits(Bits::ShiftLeft) => "Bitwise shifts a value left by another.",
Operator::Bits(Bits::ShiftRight) => "Bitwise shifts a value right by another.",
Operator::Assignment(Assignment::Assign) => "Assigns a value to a variable.",
Operator::Assignment(Assignment::AddAssign) => "Adds a value to a variable.",
Operator::Assignment(Assignment::SubtractAssign) => "Subtracts a value from a variable.",
Operator::Assignment(Assignment::MultiplyAssign) => "Multiplies a variable by a value.",
Operator::Assignment(Assignment::DivideAssign) => "Divides a variable by a value.",
Operator::Assignment(Assignment::ConcatenateAssign) => {
"Concatenates a list, a string, or a binary value to a variable of the same type."
}
}
}
#[cfg(test)]
mod test {
#[test]
fn test_examples() {
use super::HelpOperators;
use crate::test_examples;
test_examples(HelpOperators {})
}
}