1 files changed, 77 insertions, 0 deletions

diff --git a/crates/ra_ide/src/completion.rs b/crates/ra_ide/src/completion.rs
new file mode 100644
index 000000000..abe1f36ce
--- /dev/null
+++ b/crates/ra_ide/src/completion.rs
@@ -0,0 +1,77 @@
+//! FIXME: write short doc here
+
+mod completion_item;
+mod completion_context;
+mod presentation;
+
+mod complete_dot;
+mod complete_record_literal;
+mod complete_record_pattern;
+mod complete_pattern;
+mod complete_fn_param;
+mod complete_keyword;
+mod complete_snippet;
+mod complete_path;
+mod complete_scope;
+mod complete_postfix;
+mod complete_macro_in_item_position;
+
+use ra_db::SourceDatabase;
+
+#[cfg(test)]
+use crate::completion::completion_item::do_completion;
+use crate::{
+    completion::{
+        completion_context::CompletionContext,
+        completion_item::{CompletionKind, Completions},
+    },
+    db, FilePosition,
+};
+
+pub use crate::completion::completion_item::{
+    CompletionItem, CompletionItemKind, InsertTextFormat,
+};
+
+/// Main entry point for completion. We run completion as a two-phase process.
+///
+/// First, we look at the position and collect a so-called `CompletionContext.
+/// This is a somewhat messy process, because, during completion, syntax tree is
+/// incomplete and can look really weird.
+///
+/// Once the context is collected, we run a series of completion routines which
+/// look at the context and produce completion items. One subtlety about this
+/// phase is that completion engine should not filter by the substring which is
+/// already present, it should give all possible variants for the identifier at
+/// the caret. In other words, for
+///
+/// ```no-run
+/// fn f() {
+///     let foo = 92;
+///     let _ = bar<|>
+/// }
+/// ```
+///
+/// `foo` *should* be present among the completion variants. Filtering by
+/// identifier prefix/fuzzy match should be done higher in the stack, together
+/// with ordering of completions (currently this is done by the client).
+pub(crate) fn completions(db: &db::RootDatabase, position: FilePosition) -> Option<Completions> {
+    let original_parse = db.parse(position.file_id);
+    let ctx = CompletionContext::new(db, &original_parse, position)?;
+
+    let mut acc = Completions::default();
+
+    complete_fn_param::complete_fn_param(&mut acc, &ctx);
+    complete_keyword::complete_expr_keyword(&mut acc, &ctx);
+    complete_keyword::complete_use_tree_keyword(&mut acc, &ctx);
+    complete_snippet::complete_expr_snippet(&mut acc, &ctx);
+    complete_snippet::complete_item_snippet(&mut acc, &ctx);
+    complete_path::complete_path(&mut acc, &ctx);
+    complete_scope::complete_scope(&mut acc, &ctx);
+    complete_dot::complete_dot(&mut acc, &ctx);
+    complete_record_literal::complete_record_literal(&mut acc, &ctx);
+    complete_record_pattern::complete_record_pattern(&mut acc, &ctx);
+    complete_pattern::complete_pattern(&mut acc, &ctx);
+    complete_postfix::complete_postfix(&mut acc, &ctx);
+    complete_macro_in_item_position::complete_macro_in_item_position(&mut acc, &ctx);
+    Some(acc)
+}