Add new variation of query syntax

Close #18

Author: asukaminato0721

README.md

@@ -36,5 +36,12 @@ $ curl -X GET \
       "localhost:8000/search?scope=set:libstd"
 ```
 
+## Query Syntax
+
+- `fn f(type) -> type`
+- `fn (type) -> type`
+- `fn(type) -> type`
+- `(type) -> type`
+
 ## Related Project
 - [cargo-roogle](https://github.com/roogle-rs/cargo-roogle)

roogle-engine/src/query/parse.rs

@@ -37,10 +37,10 @@ where
 {
     let (i, f) = opt(tag("fn"))(i)?;
     let (i, _) = match f {
-        Some(_) => multispace1(i)?,
+        Some(_) => multispace0(i)?,
         None => multispace0(i)?,
     };
-    let (i, name) = opt(parse_symbol)(i)?;
+    let (i, name) = opt(preceded(multispace1, parse_symbol))(i)?;
     let (i, decl) = opt(parse_function)(i)?;
 
     let query = Query {