diff --git a/parser.pegjs b/parser.pegjs
index 3964ab3..ec73565 100644
--- a/parser.pegjs
+++ b/parser.pegjs
@@ -1,10 +1,30 @@
 // AST factories
 {
     const attr = (name, args) => ({ name, args })
+    const stmt = (stmt_type, args) => ({ type: "stmt", stmt_type, args })
+    const decl = (decl_type, args) => ({ type: "decl", decl_type, args })
 }
 
+Program = WS @(Decl / Stmt)* WS
+
+// Declarations
+Decl = VarDecl
+VarDecl = Attrs? type:Type name:Ident SEMI { return decl("var", { type, name }) }
+
+// Statements
+Stmt = @AssignStmt SEMI
+AssignStmt = name:Ident ASSIGN expr:Expr { return stmt("assign", { name, expr }) }
+
+// Expr
+Expr = BaseExpr
+BaseExpr = Number
+
+// Primitive types
+Type = PrimitiveType
+PrimitiveType = S8 / U8 / U16
+
 // Attributes
-Attrs = LATTR l:AttrList RATTR { return l }
+Attrs = LATTR @AttrList RATTR
 AttrList = h:Attr t:(COMMA @Attr)* { return [h].concat(t) }
     / '' { return [] }
 Attr = name:Ident args:(LPAREN @AttrArgs RPAREN)? { return attr(name, args || []) }
@@ -15,8 +35,17 @@ AttrArg = Ident / Number
 // Terminals
 Ident = h:[a-zA-Z_] t:[0-9a-zA-Z_]* WS { return h + t.join('') }
 Number = digits:[0-9]+ WS { return parseInt(digits.join(''), 10) }
+    / '0x' digits:[a-fA-F0-9]+ WS { return parseInt(digits.join(''), 16) }
+    / '0b' digits:[01]+ WS { return parseInt(digits.join(''), 2) }
+
+// Terminal keywords
+S8 = @'s8' WS
+U8 = @'u8' WS
+U16 = @'u16' WS
 
 // Terminal symbols
+SEMI = ';' WS
+ASSIGN = '<-' WS
 LPAREN = '(' WS
 RPAREN = ')' WS
 COMMA = ',' WS