Merge pull request #97 from mist-go/tidy-grammar

VC: Tidy up the grammar/parser #94

crates/codegen/src/expr.rs

@@ -256,11 +256,6 @@ impl GenRust for Postfix {
 
             Postfix::Try => cg.add("?"),
 
-            Postfix::Assign(cmp, expr) => {
-                cg.add(" ");
-                cg.add(cmp);
-                expr.gen_rust(ctx, cg);
-            }
             Postfix::Increment => cg.add("+=1"),
             Postfix::Decrement => cg.add("-=1"),
         }

crates/codegen/src/fmt/expr.rs

@@ -164,12 +164,6 @@ impl GenMist for Postfix {
                 cg.add(&ty.get_mist());
             }
             Postfix::Try => cg.add("?"),
-            Postfix::Assign(cmp, expr) => {
-                cg.add(" ");
-                cg.add(cmp);
-                cg.add(" ");
-                expr.gen_mist(ctx, cg);
-            }
             Postfix::Increment => cg.add("++"),
             Postfix::Decrement => cg.add("--"),
         }

crates/parser/src/ast/expr.rs

@@ -62,7 +62,6 @@ pub enum Postfix {
         delimiter: MacroDelimiter,
     },
     StructCall(Vec<(Identifier, Option<Expression>)>),
-    Assign(String, Box<Expression>),
     Index(Expression),
     As(TypeExpr),
     Increment,

crates/parser/src/grammar.pest

@@ -12,6 +12,7 @@ COMMENT    = _{ "//" ~ (!"\n" ~ ANY)* }
 keyword = {
     "if"
   | "else"
+  | "fn"
   | "for"
   | "while"
   | "match"
@@ -163,7 +164,7 @@ literal = {
 etc_pattern = { ".." }
 
 multi_pat_template = _{
-    ((pattern | etc_pattern) ~ ("," ~ (pattern | etc_pattern))*)?
+    ((pattern | etc_pattern) ~ ("," ~ (pattern | etc_pattern))* ~ ","?)?
 }
 
 tuple_pattern = {
@@ -290,7 +291,7 @@ enum_fields = _{
 }
 
 enum_decl = {
-    visibility? ~ "enum" ~ identifier ~ generics_decl? ~ "{" ~ enum_fields ~ "}"
+    visibility? ~ "enum" ~ identifier ~ generics_decl? ~ "{" ~ enum_fields? ~ "}"
 }
 
 // ======================================================

crates/parser/src/semantics.rs

@@ -317,12 +317,6 @@ impl GetMutability for Expression {
                 // Recurse into all postfix sub-expressions
                 for postfix in postfixes {
                     match postfix {
-                        Postfix::Assign(_, rhs) => {
-                            if let Some(self_ref) = get_self_ref(initial, postfixes) {
-                                result.push(self_ref);
-                            }
-                            result.append(&mut rhs.get_mutability());
-                        }
                         Postfix::Call(args) => {
                             for arg in args {
                                 result.append(&mut arg.get_mutability());