From 6ff8463db442fdee1cf15838d6fcf53f67a62095 Mon Sep 17 00:00:00 2001
From: Gaith Hallak <gaithhallak@gmail.com>
Date: Wed, 3 Aug 2022 00:10:44 +0400
Subject: [PATCH] Add main contract, contract interface, and guards to the docs
 syntax

---
 docs/sophia_syntax.md | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/docs/sophia_syntax.md b/docs/sophia_syntax.md
index a55fa60..6cdd9c8 100644
--- a/docs/sophia_syntax.md
+++ b/docs/sophia_syntax.md
@@ -91,7 +91,8 @@ A Sophia file consists of a sequence of *declarations* in a layout block.
 ```c
 File ::= Block(TopDecl)
 
-TopDecl ::= ['payable'] 'contract' Con '=' Block(Decl)
+TopDecl ::= ['payable'] ['main'] 'contract' Con '=' Block(Decl)
+       | 'contract' 'interface' Con '=' Block(Decl)
        | 'namespace' Con '=' Block(Decl)
        | '@compiler' PragmaOp Version
        | 'include' String
@@ -103,6 +104,9 @@ Decl ::= 'type'     Id ['(' TVar* ')'] '=' TypeAlias
 
 FunDecl ::= Id ':' Type                             // Type signature
           | Id Args [':' Type] '=' Block(Stmt)      // Definition
+          | Id Args [':' Type] Block(GuardedDef)    // Guarded definitions
+
+GuardedDef = '|' Sep(Expr, ',') '=' Block(Stmt)
 
 PragmaOp ::= '<' | '=<' | '==' | '>=' | '>'
 Version  ::= Sep1(Int, '.')