1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412
use nu_protocol::{
ast::{Call, Expression},
engine::{EngineState, Stack},
FromValue, ShellError, Span, Spanned, Value,
};
use serde::{Deserialize, Serialize};
/// A representation of the plugin's invocation command including command line args
///
/// The `EvaluatedCall` contains information about the way a `Plugin` was invoked representing the
/// [`Span`] corresponding to the invocation as well as the arguments it was invoked with. It is
/// one of the items passed to `PluginCommand::run()`, along with the plugin reference, the engine
/// interface, and a [`Value`] that represents the input.
///
/// The evaluated call is used with the Plugins because the plugin doesn't have
/// access to the Stack and the EngineState the way a built in command might. For that
/// reason, before encoding the message to the plugin all the arguments to the original
/// call (which are expressions) are evaluated and passed to Values
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct EvaluatedCall {
/// Span of the command invocation
pub head: Span,
/// Values of positional arguments
pub positional: Vec<Value>,
/// Names and values of named arguments
pub named: Vec<(Spanned<String>, Option<Value>)>,
}
impl EvaluatedCall {
/// Try to create an [`EvaluatedCall`] from a command `Call`.
pub fn try_from_call(
call: &Call,
engine_state: &EngineState,
stack: &mut Stack,
eval_expression_fn: fn(&EngineState, &mut Stack, &Expression) -> Result<Value, ShellError>,
) -> Result<Self, ShellError> {
let positional =
call.rest_iter_flattened(0, |expr| eval_expression_fn(engine_state, stack, expr))?;
let mut named = Vec::with_capacity(call.named_len());
for (string, _, expr) in call.named_iter() {
let value = match expr {
None => None,
Some(expr) => Some(eval_expression_fn(engine_state, stack, expr)?),
};
named.push((string.clone(), value))
}
Ok(Self {
head: call.head,
positional,
named,
})
}
/// Check if a flag (named parameter that does not take a value) is set
/// Returns Ok(true) if flag is set or passed true value
/// Returns Ok(false) if flag is not set or passed false value
/// Returns Err if passed value is not a boolean
///
/// # Examples
/// Invoked as `my_command --foo`:
/// ```
/// # use nu_protocol::{Spanned, Span, Value};
/// # use nu_plugin_protocol::EvaluatedCall;
/// # let null_span = Span::new(0, 0);
/// # let call = EvaluatedCall {
/// # head: null_span,
/// # positional: Vec::new(),
/// # named: vec![(
/// # Spanned { item: "foo".to_owned(), span: null_span},
/// # None
/// # )],
/// # };
/// assert!(call.has_flag("foo").unwrap());
/// ```
///
/// Invoked as `my_command --bar`:
/// ```
/// # use nu_protocol::{Spanned, Span, Value};
/// # use nu_plugin_protocol::EvaluatedCall;
/// # let null_span = Span::new(0, 0);
/// # let call = EvaluatedCall {
/// # head: null_span,
/// # positional: Vec::new(),
/// # named: vec![(
/// # Spanned { item: "bar".to_owned(), span: null_span},
/// # None
/// # )],
/// # };
/// assert!(!call.has_flag("foo").unwrap());
/// ```
///
/// Invoked as `my_command --foo=true`:
/// ```
/// # use nu_protocol::{Spanned, Span, Value};
/// # use nu_plugin_protocol::EvaluatedCall;
/// # let null_span = Span::new(0, 0);
/// # let call = EvaluatedCall {
/// # head: null_span,
/// # positional: Vec::new(),
/// # named: vec![(
/// # Spanned { item: "foo".to_owned(), span: null_span},
/// # Some(Value::bool(true, Span::unknown()))
/// # )],
/// # };
/// assert!(call.has_flag("foo").unwrap());
/// ```
///
/// Invoked as `my_command --foo=false`:
/// ```
/// # use nu_protocol::{Spanned, Span, Value};
/// # use nu_plugin_protocol::EvaluatedCall;
/// # let null_span = Span::new(0, 0);
/// # let call = EvaluatedCall {
/// # head: null_span,
/// # positional: Vec::new(),
/// # named: vec![(
/// # Spanned { item: "foo".to_owned(), span: null_span},
/// # Some(Value::bool(false, Span::unknown()))
/// # )],
/// # };
/// assert!(!call.has_flag("foo").unwrap());
/// ```
///
/// Invoked with wrong type as `my_command --foo=1`:
/// ```
/// # use nu_protocol::{Spanned, Span, Value};
/// # use nu_plugin_protocol::EvaluatedCall;
/// # let null_span = Span::new(0, 0);
/// # let call = EvaluatedCall {
/// # head: null_span,
/// # positional: Vec::new(),
/// # named: vec![(
/// # Spanned { item: "foo".to_owned(), span: null_span},
/// # Some(Value::int(1, Span::unknown()))
/// # )],
/// # };
/// assert!(call.has_flag("foo").is_err());
/// ```
pub fn has_flag(&self, flag_name: &str) -> Result<bool, ShellError> {
for name in &self.named {
if flag_name == name.0.item {
return match &name.1 {
Some(Value::Bool { val, .. }) => Ok(*val),
None => Ok(true),
Some(result) => Err(ShellError::CantConvert {
to_type: "bool".into(),
from_type: result.get_type().to_string(),
span: result.span(),
help: Some("".into()),
}),
};
}
}
Ok(false)
}
/// Returns the [`Value`] of an optional named argument
///
/// # Examples
/// Invoked as `my_command --foo 123`:
/// ```
/// # use nu_protocol::{Spanned, Span, Value};
/// # use nu_plugin_protocol::EvaluatedCall;
/// # let null_span = Span::new(0, 0);
/// # let call = EvaluatedCall {
/// # head: null_span,
/// # positional: Vec::new(),
/// # named: vec![(
/// # Spanned { item: "foo".to_owned(), span: null_span},
/// # Some(Value::int(123, null_span))
/// # )],
/// # };
/// let opt_foo = match call.get_flag_value("foo") {
/// Some(Value::Int { val, .. }) => Some(val),
/// None => None,
/// _ => panic!(),
/// };
/// assert_eq!(opt_foo, Some(123));
/// ```
///
/// Invoked as `my_command`:
/// ```
/// # use nu_protocol::{Spanned, Span, Value};
/// # use nu_plugin_protocol::EvaluatedCall;
/// # let null_span = Span::new(0, 0);
/// # let call = EvaluatedCall {
/// # head: null_span,
/// # positional: Vec::new(),
/// # named: vec![],
/// # };
/// let opt_foo = match call.get_flag_value("foo") {
/// Some(Value::Int { val, .. }) => Some(val),
/// None => None,
/// _ => panic!(),
/// };
/// assert_eq!(opt_foo, None);
/// ```
pub fn get_flag_value(&self, flag_name: &str) -> Option<Value> {
for name in &self.named {
if flag_name == name.0.item {
return name.1.clone();
}
}
None
}
/// Returns the [`Value`] of a given (zero indexed) positional argument, if present
///
/// Examples:
/// Invoked as `my_command a b c`:
/// ```
/// # use nu_protocol::{Spanned, Span, Value};
/// # use nu_plugin_protocol::EvaluatedCall;
/// # let null_span = Span::new(0, 0);
/// # let call = EvaluatedCall {
/// # head: null_span,
/// # positional: vec![
/// # Value::string("a".to_owned(), null_span),
/// # Value::string("b".to_owned(), null_span),
/// # Value::string("c".to_owned(), null_span),
/// # ],
/// # named: vec![],
/// # };
/// let arg = match call.nth(1) {
/// Some(Value::String { val, .. }) => val,
/// _ => panic!(),
/// };
/// assert_eq!(arg, "b".to_owned());
///
/// let arg = call.nth(7);
/// assert!(arg.is_none());
/// ```
pub fn nth(&self, pos: usize) -> Option<Value> {
self.positional.get(pos).cloned()
}
/// Returns the value of a named argument interpreted as type `T`
///
/// # Examples
/// Invoked as `my_command --foo 123`:
/// ```
/// # use nu_protocol::{Spanned, Span, Value};
/// # use nu_plugin_protocol::EvaluatedCall;
/// # let null_span = Span::new(0, 0);
/// # let call = EvaluatedCall {
/// # head: null_span,
/// # positional: Vec::new(),
/// # named: vec![(
/// # Spanned { item: "foo".to_owned(), span: null_span},
/// # Some(Value::int(123, null_span))
/// # )],
/// # };
/// let foo = call.get_flag::<i64>("foo");
/// assert_eq!(foo.unwrap(), Some(123));
/// ```
///
/// Invoked as `my_command --bar 123`:
/// ```
/// # use nu_protocol::{Spanned, Span, Value};
/// # use nu_plugin_protocol::EvaluatedCall;
/// # let null_span = Span::new(0, 0);
/// # let call = EvaluatedCall {
/// # head: null_span,
/// # positional: Vec::new(),
/// # named: vec![(
/// # Spanned { item: "bar".to_owned(), span: null_span},
/// # Some(Value::int(123, null_span))
/// # )],
/// # };
/// let foo = call.get_flag::<i64>("foo");
/// assert_eq!(foo.unwrap(), None);
/// ```
///
/// Invoked as `my_command --foo abc`:
/// ```
/// # use nu_protocol::{Spanned, Span, Value};
/// # use nu_plugin_protocol::EvaluatedCall;
/// # let null_span = Span::new(0, 0);
/// # let call = EvaluatedCall {
/// # head: null_span,
/// # positional: Vec::new(),
/// # named: vec![(
/// # Spanned { item: "foo".to_owned(), span: null_span},
/// # Some(Value::string("abc".to_owned(), null_span))
/// # )],
/// # };
/// let foo = call.get_flag::<i64>("foo");
/// assert!(foo.is_err());
/// ```
pub fn get_flag<T: FromValue>(&self, name: &str) -> Result<Option<T>, ShellError> {
if let Some(value) = self.get_flag_value(name) {
FromValue::from_value(value).map(Some)
} else {
Ok(None)
}
}
/// Retrieve the Nth and all following positional arguments as type `T`
///
/// # Example
/// Invoked as `my_command zero one two three`:
/// ```
/// # use nu_protocol::{Spanned, Span, Value};
/// # use nu_plugin_protocol::EvaluatedCall;
/// # let null_span = Span::new(0, 0);
/// # let call = EvaluatedCall {
/// # head: null_span,
/// # positional: vec![
/// # Value::string("zero".to_owned(), null_span),
/// # Value::string("one".to_owned(), null_span),
/// # Value::string("two".to_owned(), null_span),
/// # Value::string("three".to_owned(), null_span),
/// # ],
/// # named: Vec::new(),
/// # };
/// let args = call.rest::<String>(0);
/// assert_eq!(args.unwrap(), vec!["zero", "one", "two", "three"]);
///
/// let args = call.rest::<String>(2);
/// assert_eq!(args.unwrap(), vec!["two", "three"]);
/// ```
pub fn rest<T: FromValue>(&self, starting_pos: usize) -> Result<Vec<T>, ShellError> {
self.positional
.iter()
.skip(starting_pos)
.map(|value| FromValue::from_value(value.clone()))
.collect()
}
/// Retrieve the value of an optional positional argument interpreted as type `T`
///
/// Returns the value of a (zero indexed) positional argument of type `T`.
/// Alternatively returns [`None`] if the positional argument does not exist
/// or an error that can be passed back to the shell on error.
pub fn opt<T: FromValue>(&self, pos: usize) -> Result<Option<T>, ShellError> {
if let Some(value) = self.nth(pos) {
FromValue::from_value(value).map(Some)
} else {
Ok(None)
}
}
/// Retrieve the value of a mandatory positional argument as type `T`
///
/// Expect a positional argument of type `T` and return its value or, if the
/// argument does not exist or is of the wrong type, return an error that can
/// be passed back to the shell.
pub fn req<T: FromValue>(&self, pos: usize) -> Result<T, ShellError> {
if let Some(value) = self.nth(pos) {
FromValue::from_value(value)
} else if self.positional.is_empty() {
Err(ShellError::AccessEmptyContent { span: self.head })
} else {
Err(ShellError::AccessBeyondEnd {
max_idx: self.positional.len() - 1,
span: self.head,
})
}
}
}
#[cfg(test)]
mod test {
use super::*;
use nu_protocol::{Span, Spanned, Value};
#[test]
fn call_to_value() {
let call = EvaluatedCall {
head: Span::new(0, 10),
positional: vec![
Value::float(1.0, Span::new(0, 10)),
Value::string("something", Span::new(0, 10)),
],
named: vec![
(
Spanned {
item: "name".to_string(),
span: Span::new(0, 10),
},
Some(Value::float(1.0, Span::new(0, 10))),
),
(
Spanned {
item: "flag".to_string(),
span: Span::new(0, 10),
},
None,
),
],
};
let name: Option<f64> = call.get_flag("name").unwrap();
assert_eq!(name, Some(1.0));
assert!(call.has_flag("flag").unwrap());
let required: f64 = call.req(0).unwrap();
assert!((required - 1.0).abs() < f64::EPSILON);
let optional: Option<String> = call.opt(1).unwrap();
assert_eq!(optional, Some("something".to_string()));
let rest: Vec<String> = call.rest(1).unwrap();
assert_eq!(rest, vec!["something".to_string()]);
}
}