forked from extern/nushell
95 lines
2.9 KiB
Rust
95 lines
2.9 KiB
Rust
use nu_engine::{eval_block, eval_expression};
|
|
use nu_protocol::ast::Call;
|
|
use nu_protocol::engine::{Command, EvaluationContext};
|
|
use nu_protocol::{IntoValueStream, Signature, SyntaxShape, Value};
|
|
|
|
pub struct For;
|
|
|
|
impl Command for For {
|
|
fn name(&self) -> &str {
|
|
"for"
|
|
}
|
|
|
|
fn usage(&self) -> &str {
|
|
"Loop over a range"
|
|
}
|
|
|
|
fn signature(&self) -> nu_protocol::Signature {
|
|
Signature::build("for")
|
|
.required(
|
|
"var_name",
|
|
SyntaxShape::Variable,
|
|
"name of the looping variable",
|
|
)
|
|
.required(
|
|
"range",
|
|
SyntaxShape::Keyword(
|
|
b"in".to_vec(),
|
|
Box::new(SyntaxShape::List(Box::new(SyntaxShape::Int))),
|
|
),
|
|
"range of the loop",
|
|
)
|
|
.required(
|
|
"block",
|
|
SyntaxShape::Block(Some(vec![])),
|
|
"the block to run",
|
|
)
|
|
}
|
|
|
|
fn run(
|
|
&self,
|
|
context: &EvaluationContext,
|
|
call: &Call,
|
|
_input: Value,
|
|
) -> Result<nu_protocol::Value, nu_protocol::ShellError> {
|
|
let var_id = call.positional[0]
|
|
.as_var()
|
|
.expect("internal error: missing variable");
|
|
|
|
let keyword_expr = call.positional[1]
|
|
.as_keyword()
|
|
.expect("internal error: missing keyword");
|
|
let values = eval_expression(context, keyword_expr)?;
|
|
|
|
let block = call.positional[2]
|
|
.as_block()
|
|
.expect("internal error: expected block");
|
|
let context = context.clone();
|
|
|
|
match values {
|
|
Value::Stream { stream, .. } => Ok(Value::Stream {
|
|
stream: stream
|
|
.map(move |x| {
|
|
let engine_state = context.engine_state.borrow();
|
|
let block = engine_state.get_block(block);
|
|
|
|
let state = context.enter_scope();
|
|
state.add_var(var_id, x);
|
|
|
|
//FIXME: DON'T UNWRAP
|
|
eval_block(&state, block, Value::nothing()).unwrap()
|
|
})
|
|
.into_value_stream(),
|
|
span: call.head,
|
|
}),
|
|
Value::List { vals: val, .. } => Ok(Value::List {
|
|
vals: val
|
|
.into_iter()
|
|
.map(move |x| {
|
|
let engine_state = context.engine_state.borrow();
|
|
let block = engine_state.get_block(block);
|
|
|
|
let state = context.enter_scope();
|
|
state.add_var(var_id, x);
|
|
|
|
//FIXME: DON'T UNWRAP
|
|
eval_block(&state, block, Value::nothing()).unwrap()
|
|
})
|
|
.collect(),
|
|
span: call.head,
|
|
}),
|
|
_ => Ok(Value::nothing()),
|
|
}
|
|
}
|
|
}
|