ast.m

来自「用YACC实现的一个小的编译工具」· M 代码 · 共 29 行

domain Statement {

   assignment (Expression lhs, Expression rhs)
   print (Expression x)
   ifstmt (Expression cond, Statement thenpart, Statement elsepart)
   whilestmt (Expression cond, Statement body)
   seq (Statement s1, Statement s2)
   empty()

}

domain Expression {

   eq (Expression x, Expression y)
   ne (Expression x, Expression y)
   lt (Expression x, Expression y)
   le (Expression x, Expression y)
   gt (Expression x, Expression y)
   ge (Expression x, Expression y)
   plus (Expression x, Expression y)
   minus (Expression x, Expression y)
   mult (Expression x, Expression y)
   divide (Expression x, Expression y)
   neg (Expression x)
   number (int x)
   name(int location)

}