new trailing body macros implemented from c3c #1906

Author: alexveden

lib/c3tools/codefmt/_formatters.c3

@@ -320,6 +320,14 @@ fn bool! CodeFmt.format_fn(CodeFmt* self, Token* t, NodeParserState* state) @pri
                 case IMPLIES:
                     self.write(" %s ", t.value);
                     break;
+                case LBRACE: 
+                    // fn int foo(int x) => @pool() { ... } 
+                    if (state.scope_depth == 1) {
+                        self.cache_statement_dump(no_split: true)!;
+                        nextcase STATE: state.transition(SCOPE);
+                    } else {
+                        nextcase default;
+                    }
                 case EOS:
                     self.cache_statement_add(state, t);
                     self.cache_statement_dump(no_split: true)!;

test/c3tools/codefmt/c3fmt_corpus/macros.txt

@@ -174,3 +174,19 @@ macro matrix_component_mul(mat, val) @private
     var $Type = Real[<$typeof(mat.m).len>];
     return $typeof(*mat){ .m = val * ($Type)mat.m };
 }
+================================================================================
+fn_trailing_body
+================================================================================
+fn int foo(int x) => @pool()
+{
+    String s = string::tformat("%d", x);
+    io::printn(s);
+    return 2;
+}
+--------------------------------------------------------------------------------
+fn int foo(int x) => @pool()
+{
+    String s = string::tformat("%d", x);
+    io::printn(s);
+    return 2;
+}