rust/crates/ide_completion/src/render/struct_literal.rs
2021-10-05 09:00:21 +11:00

116 lines
3.3 KiB
Rust

//! Renderer for `struct` literal.
use hir::{db::HirDatabase, HasAttrs, HasVisibility, Name, StructKind};
use ide_db::helpers::SnippetCap;
use itertools::Itertools;
use crate::{item::CompletionKind, render::RenderContext, CompletionItem, CompletionItemKind};
pub(crate) fn render_struct_literal(
ctx: RenderContext<'_>,
strukt: hir::Struct,
local_name: Option<Name>,
) -> Option<CompletionItem> {
let _p = profile::span("render_struct_literal");
let fields = strukt.fields(ctx.db());
let (visible_fields, fields_omitted) = visible_fields(&ctx, &fields, strukt)?;
if fields_omitted {
// If some fields are private you can't make `struct` literal.
return None;
}
let name = local_name.unwrap_or_else(|| strukt.name(ctx.db())).to_string();
let literal = render_literal(&ctx, &name, strukt.kind(ctx.db()), &visible_fields)?;
Some(build_completion(ctx, name, literal, strukt))
}
fn build_completion(
ctx: RenderContext<'_>,
name: String,
literal: String,
def: impl HasAttrs + Copy,
) -> CompletionItem {
let mut item = CompletionItem::new(CompletionKind::Snippet, ctx.source_range(), name + " {…}");
item.kind(CompletionItemKind::Snippet)
.set_documentation(ctx.docs(def))
.set_deprecated(ctx.is_deprecated(def))
.detail(&literal);
match ctx.snippet_cap() {
Some(snippet_cap) => item.insert_snippet(snippet_cap, literal),
None => item.insert_text(literal),
};
item.build()
}
fn render_literal(
ctx: &RenderContext<'_>,
name: &str,
kind: StructKind,
fields: &[hir::Field],
) -> Option<String> {
let mut literal = match kind {
StructKind::Tuple if ctx.snippet_cap().is_some() => render_tuple_as_literal(fields, name),
StructKind::Record => render_record_as_literal(ctx.db(), ctx.snippet_cap(), fields, name),
_ => return None,
};
if ctx.snippet_cap().is_some() {
literal.push_str("$0");
}
Some(literal)
}
fn render_record_as_literal(
db: &dyn HirDatabase,
snippet_cap: Option<SnippetCap>,
fields: &[hir::Field],
name: &str,
) -> String {
let fields = fields.iter();
if snippet_cap.is_some() {
format!(
"{name} {{ {} }}",
fields
.enumerate()
.map(|(idx, field)| format!("{}: ${{{}:()}}", field.name(db), idx + 1))
.format(", "),
name = name
)
} else {
format!(
"{name} {{ {} }}",
fields.map(|field| format!("{}: ()", field.name(db))).format(", "),
name = name
)
}
}
fn render_tuple_as_literal(fields: &[hir::Field], name: &str) -> String {
format!(
"{name}({})",
fields.iter().enumerate().map(|(idx, _)| format!("${}", idx + 1)).format(", "),
name = name
)
}
fn visible_fields(
ctx: &RenderContext<'_>,
fields: &[hir::Field],
item: impl HasAttrs,
) -> Option<(Vec<hir::Field>, bool)> {
let module = ctx.completion.scope.module()?;
let n_fields = fields.len();
let fields = fields
.iter()
.filter(|field| field.is_visible_from(ctx.db(), module))
.copied()
.collect::<Vec<_>>();
let fields_omitted =
n_fields - fields.len() > 0 || item.attrs(ctx.db()).by_key("non_exhaustive").exists();
Some((fields, fields_omitted))
}