nushell/crates/nu-cli/src/completions/variable_completions.rs
2022-06-22 13:13:03 -05:00

293 lines
9.6 KiB
Rust

use crate::completions::{Completer, CompletionOptions};
use nu_engine::eval_variable;
use nu_protocol::{
engine::{EngineState, Stack, StateWorkingSet},
Span, Value,
};
use reedline::Suggestion;
use std::str;
use std::sync::Arc;
#[derive(Clone)]
pub struct VariableCompletion {
engine_state: Arc<EngineState>, // TODO: Is engine state necessary? It's already a part of working set in fetch()
stack: Stack,
var_context: (Vec<u8>, Vec<Vec<u8>>), // tuple with $var and the sublevels (.b.c.d)
}
impl VariableCompletion {
pub fn new(
engine_state: Arc<EngineState>,
stack: Stack,
var_context: (Vec<u8>, Vec<Vec<u8>>),
) -> Self {
Self {
engine_state,
stack,
var_context,
}
}
}
impl Completer for VariableCompletion {
fn fetch(
&mut self,
working_set: &StateWorkingSet,
prefix: Vec<u8>,
span: Span,
offset: usize,
_: usize,
options: &CompletionOptions,
) -> Vec<Suggestion> {
let mut output = vec![];
let builtins = ["$nu", "$in", "$env", "$nothing"];
let var_str = std::str::from_utf8(&self.var_context.0)
.unwrap_or("")
.to_lowercase();
let var_id = working_set.find_variable(&self.var_context.0);
let current_span = reedline::Span {
start: span.start - offset,
end: span.end - offset,
};
let sublevels_count = self.var_context.1.len();
// Completions for the given variable
if !var_str.is_empty() {
// Completion for $env.<tab>
if var_str.as_str() == "$env" {
let env_vars = self.stack.get_env_vars(&self.engine_state);
// Return nested values
if sublevels_count > 0 {
// Extract the target var ($env.<target-var>)
let target_var = self.var_context.1[0].clone();
let target_var_str =
str::from_utf8(&target_var).unwrap_or_default().to_string();
// Everything after the target var is the nested level ($env.<target-var>.<nested_levels>...)
let nested_levels: Vec<Vec<u8>> =
self.var_context.1.clone().into_iter().skip(1).collect();
if let Some(val) = env_vars.get(&target_var_str) {
for suggestion in
nested_suggestions(val.clone(), nested_levels, current_span)
{
if options
.match_algorithm
.matches_u8(suggestion.value.as_bytes(), &prefix)
{
output.push(suggestion);
}
}
return output;
}
} else {
// No nesting provided, return all env vars
for env_var in env_vars {
if options
.match_algorithm
.matches_u8(env_var.0.as_bytes(), &prefix)
{
output.push(Suggestion {
value: env_var.0,
description: None,
extra: None,
span: current_span,
append_whitespace: false,
});
}
}
return output;
}
}
// Completions for $nu.<tab>
if var_str.as_str() == "$nu" {
// Eval nu var
if let Ok(nuval) = eval_variable(
&self.engine_state,
&self.stack,
nu_protocol::NU_VARIABLE_ID,
nu_protocol::Span {
start: current_span.start,
end: current_span.end,
},
) {
for suggestion in
nested_suggestions(nuval, self.var_context.1.clone(), current_span)
{
if options
.match_algorithm
.matches_u8(suggestion.value.as_bytes(), &prefix)
{
output.push(suggestion);
}
}
return output;
}
}
// Completion other variable types
if let Some(var_id) = var_id {
// Extract the variable value from the stack
let var = self.stack.get_var(
var_id,
Span {
start: span.start,
end: span.end,
},
);
// If the value exists and it's of type Record
if let Ok(value) = var {
for suggestion in
nested_suggestions(value, self.var_context.1.clone(), current_span)
{
if options
.match_algorithm
.matches_u8(suggestion.value.as_bytes(), &prefix)
{
output.push(suggestion);
}
}
return output;
}
}
}
// Variable completion (e.g: $en<tab> to complete $env)
for builtin in builtins {
if options
.match_algorithm
.matches_u8(builtin.as_bytes(), &prefix)
{
output.push(Suggestion {
value: builtin.to_string(),
description: None,
extra: None,
span: current_span,
append_whitespace: false,
});
}
}
// TODO: The following can be refactored (see find_commands_by_predicate() used in
// command_completions).
let mut removed_overlays = vec![];
// Working set scope vars
for scope_frame in working_set.delta.scope.iter().rev() {
for overlay_frame in scope_frame
.active_overlays(&mut removed_overlays)
.iter()
.rev()
{
for v in &overlay_frame.vars {
if options.match_algorithm.matches_u8(v.0, &prefix) {
output.push(Suggestion {
value: String::from_utf8_lossy(v.0).to_string(),
description: None,
extra: None,
span: current_span,
append_whitespace: false,
});
}
}
}
}
// Permanent state vars
// for scope in &self.engine_state.scope {
for overlay_frame in self
.engine_state
.active_overlays(&removed_overlays)
.iter()
.rev()
{
for v in &overlay_frame.vars {
if options.match_algorithm.matches_u8(v.0, &prefix) {
output.push(Suggestion {
value: String::from_utf8_lossy(v.0).to_string(),
description: None,
extra: None,
span: current_span,
append_whitespace: false,
});
}
}
}
output.dedup(); // TODO: Removes only consecutive duplicates, is it intended?
output
}
}
// Find recursively the values for sublevels
// if no sublevels are set it returns the current value
fn nested_suggestions(
val: Value,
sublevels: Vec<Vec<u8>>,
current_span: reedline::Span,
) -> Vec<Suggestion> {
let mut output: Vec<Suggestion> = vec![];
let value = recursive_value(val, sublevels);
match value {
Value::Record {
cols,
vals: _,
span: _,
} => {
// Add all the columns as completion
for item in cols {
output.push(Suggestion {
value: item,
description: None,
extra: None,
span: current_span,
append_whitespace: false,
});
}
output
}
_ => output,
}
}
// Extracts the recursive value (e.g: $var.a.b.c)
fn recursive_value(val: Value, sublevels: Vec<Vec<u8>>) -> Value {
// Go to next sublevel
if let Some(next_sublevel) = sublevels.clone().into_iter().next() {
match val {
Value::Record {
cols,
vals,
span: _,
} => {
for item in cols.into_iter().zip(vals.into_iter()) {
// Check if index matches with sublevel
if item.0.as_bytes().to_vec() == next_sublevel {
// If matches try to fetch recursively the next
return recursive_value(item.1, sublevels.into_iter().skip(1).collect());
}
}
// Current sublevel value not found
return Value::Nothing {
span: Span { start: 0, end: 0 },
};
}
_ => return val,
}
}
val
}