SSR: Allow function calls to match method calls

This differs from how this used to work before I removed it in that:
a) It's only one direction. Function calls in the pattern can match
method calls in the code, but not the other way around.
b) We now check that the function call in the pattern resolves to the
same function as the method call in the code.

The lack of (b) was the reason I felt the need to remove the feature
before.

1 files changed, 3 insertions, 0 deletions

diff --git a/crates/ra_ide/src/ssr.rs b/crates/ra_ide/src/ssr.rs
index 2f40bac08..95d8f79b8 100644
--- a/crates/ra_ide/src/ssr.rs
+++ b/crates/ra_ide/src/ssr.rs
@@ -21,6 +21,9 @@ use ra_ssr::{MatchFinder, SsrError, SsrRule};
 // replacement occurs. For example if our replacement template is `foo::Bar` and we match some
 // code in the `foo` module, we'll insert just `Bar`.
 //
+// Method calls should generally be written in UFCS form. e.g. `foo::Bar::baz($s, $a)` will match
+// `$s.baz($a)`, provided the method call `baz` resolves to the method `foo::Bar::baz`.
+//
 // Placeholders may be given constraints by writing them as `${<name>:<constraint1>:<constraint2>...}`.
 //
 // Supported constraints: