语法分析器的生成-脚本编程之：perl语言入门(第五版中文版)下载

SQLite的语法分析器是用 Lemon 生成的(Lemon是一个开源的 LALR(1)语法分析器的生成 器，SQLite在使用时进行了定制)。该分析器用 parse.c内定义的语法规则将一串词组织成层 次结构的分析树(parse tree)。 The parse tree is primarily composed of expressions and lists of expressions. An expression itself is a recursive structure that can contain subexpressions under it. For example, the WHERE clause in a SELECT parse tree is represented by a single expression. The SELECT clause, on the other hand, is represented as a list of expressions; each expression is a column that will be returned in the result set. 例如，如下简单的 SQL语句： SELECT rowid, name, season FROM episodes WHERE rowid=1 LIMIT 1 119