一个面向对象的编程语言的AST（抽象语法树）是什么样的？
我正在阅读关于AST（抽象语法树），但我看到的所有示例使用expression式，如：
a + b * c 这可以用类似下面的语法来表示：
(+ a (* bc) )
这将相当于：
+ / \ a * / \ bc
我的问题是一个OOPL中类的AST如何？
我天真的尝试是这个Java代码：
class Person { String name; int age; public String toString() { return "name"; } }
方法是：
;Hand written (classDeclaration Person (varDeclaration String name) (varDeclaration int age ) (funcDeclaration String toString (return "name") ) )
但是我不太清楚我到一个真正的AST代表有多远或多远。
这取决于我select的语言吗？ 需要多less细节？ 这些“xyzDeclaraction”是否需要或可能是：
(Person (String name) (int age))
我在哪里可以看到一个真正的编程语言的“真实”表示，以了解更多信息。
AST是CST（ 具体语法树或parsing树）的抽象。 具体的语法树是用于parsing文件的生成（在语法中）的树。 所以你的AST基本上是从你的语法定义派生出来的，但是已经转化了
Exp / | \ / | \ * Ident BinOp Ident into / \ / | \ "x" "y" / | \ "x" * "y"
总而言之，我认为你的post中的例子看起来很好。 我可能varDeclList的variables声明和varDeclList的函数声明以及methDeclList的return语句stmtList 。 （见下文。）
AST的一个或多或less的“真实”表示是由苹果在他的书“现代编译器在Java中的实现”中描述的。 （资源可以在这里find。）
使用这些类，你的程序将被表示如下：
Program ClassDeclList ClassDecl Identifier id: Person VarDeclList VarDecl type: String id: name VarDecl type: int id: age MethDeclList MethodDecl modifiers: public returnType: String id: toString Formals (empty) StmtList returnStmt Identifier id: name
OP： 我在哪里可以看到实际编程语言的真实表示以了解更多信息？
对于你的源文件作为文件Person.java：
class Person { String name; int age; public String toString() { return "name"; } }
接下来在DMS Software Reengineering Toolkit的parsing器树的Sexpression式样式转储中使用了它的Java1.6parsing器，它们都是具体的和抽象的语法树。 所有的表象复杂性都是由语言的真实复杂性（例如，Java本身）造成的。
CST明显包含比AST（54个节点）更多的东西（139个节点）。 在AST的基础上，AST会放弃从语法中自动推断出来的所有东西。 这包括将由左或右recursion语法规则引起的不带值的叶子，一元生产和压缩脊柱移除到显式列表节点。
左paren信号一个新的子树。 在左边的paren之后是节点types的名称; @ Java〜Java1_.6似乎是不必要的，除非你知道DMS可以同时处理多种语言，包括嵌套在另一个语言中的语言。 #nnnnnn是节点的内存地址。 M表示这个节点有M个父节点，当M == 1时节点离开，节点内部是节点值，{M}表示这个节点节点有M个列表子节点，每个节点都加上位置信息。
这是具体的语法树（详见AST）：
(compilation_unit@Java~Java1_6=1#4885d00^0 Line 1 Column 1 File C:/temp/Person.java (type_declarations@Java~Java1_6=15#4885cc0 Line 1 Column 1 File C:/temp/Person.java (type_declarations@Java~Java1_6=16#4884d80 Line 1 Column 1 File C:/temp/Person.java)type_declarations (type_declaration@Java~Java1_6=17#4885ca0 Line 1 Column 1 File C:/temp/Person.java (type_class_modifiers@Java~Java1_6=77#4884dc0 Line 1 Column 1 File C:/temp/Person.java)type_class_modifiers (class_header@Java~Java1_6=89#4884ec0 Line 1 Column 1 File C:/temp/Person.java |('class'@Java~Java1_6=459#4884c60[Keyword:0] Line 1 Column 1 File C:/temp/Person.java)'class' |(IDENTIFIER@Java~Java1_6=447#4884e20[`Person'] Line 1 Column 7 File C:/temp/Person.java)IDENTIFIER |(type_parameters@Java~Java1_6=408#4884e80 Line 1 Column 14 File C:/temp/Person.java)type_parameters )class_header (class_body@Java~Java1_6=94#4885c80 Line 1 Column 14 File C:/temp/Person.java |('{'@Java~Java1_6=448#4884e60[Keyword:0] Line 1 Column 14 File C:/temp/Person.java)'{' |(class_body_declarations@Java~Java1_6=111#4885c60 Line 2 Column 5 File C:/temp/Person.java | (class_body_declarations@Java~Java1_6=111#4885380 Line 2 Column 5 File C:/temp/Person.java | (class_body_declarations@Java~Java1_6=110#4885400 Line 2 Column 5 File C:/temp/Person.java | (class_body_declaration@Java~Java1_6=118#4885360 Line 2 Column 5 File C:/temp/Person.java | |(field_declaration@Java~Java1_6=168#4885440 Line 2 Column 5 File C:/temp/Person.java | | (field_modifiers@Java~Java1_6=170#4884f40 Line 2 Column 5 File C:/temp/Person.java)field_modifiers | | (type@Java~Java1_6=191#48852c0 Line 2 Column 5 File C:/temp/Person.java | | (name@Java~Java1_6=406#48851e0 Line 2 Column 5 File C:/temp/Person.java | | (IDENTIFIER@Java~Java1_6=447#4884f20[`String'] Line 2 Column 5 File C:/temp/Person.java)IDENTIFIER | | (type_arguments@Java~Java1_6=407#4885160 Line 2 Column 12 File C:/temp/Person.java)type_arguments | | )name | | (brackets@Java~Java1_6=157#4885260 Line 2 Column 12 File C:/temp/Person.java)brackets | | )type | | (variable_declarator_list@Java~Java1_6=179#4884e00 Line 2 Column 12 File C:/temp/Person.java | | (variable_declarator@Java~Java1_6=181#4885300 Line 2 Column 12 File C:/temp/Person.java | | (variable_declarator_id@Java~Java1_6=167#4885320 Line 2 Column 12 File C:/temp/Person.java | | |(IDENTIFIER@Java~Java1_6=447#4885140[`name'] Line 2 Column 12 File C:/temp/Person.java)IDENTIFIER | | |(brackets@Java~Java1_6=157#4885040 Line 2 Column 16 File C:/temp/Person.java)brackets | | )variable_declarator_id | | )variable_declarator | | )variable_declarator_list | | (';'@Java~Java1_6=440#4885100[Keyword:0] Line 2 Column 16 File C:/temp/Person.java)';' | |)field_declaration | )class_body_declaration | )class_body_declarations | (class_body_declaration@Java~Java1_6=118#48852e0 Line 3 Column 5 File C:/temp/Person.java | (field_declaration@Java~Java1_6=168#4885480 Line 3 Column 5 File C:/temp/Person.java | |(field_modifiers@Java~Java1_6=170#4885340 Line 3 Column 5 File C:/temp/Person.java)field_modifiers | |(type@Java~Java1_6=192#4885220 Line 3 Column 5 File C:/temp/Person.java | | (primitive_type@Java~Java1_6=198#4885420 Line 3 Column 5 File C:/temp/Person.java | | ('int'@Java~Java1_6=479#48853e0[Keyword:0] Line 3 Column 5 File C:/temp/Person.java)'int' | | )primitive_type | | (brackets@Java~Java1_6=157#4885200 Line 3 Column 12 File C:/temp/Person.java)brackets | |)type | |(variable_declarator_list@Java~Java1_6=179#4885540 Line 3 Column 12 File C:/temp/Person.java | | (variable_declarator@Java~Java1_6=181#4885520 Line 3 Column 12 File C:/temp/Person.java | | (variable_declarator_id@Java~Java1_6=167#4885500 Line 3 Column 12 File C:/temp/Person.java | | (IDENTIFIER@Java~Java1_6=447#4884fc0[`age'] Line 3 Column 12 File C:/temp/Person.java)IDENTIFIER | | (brackets@Java~Java1_6=157#48854e0 Line 3 Column 15 File C:/temp/Person.java)brackets | | )variable_declarator_id | | )variable_declarator | |)variable_declarator_list | |(';'@Java~Java1_6=440#48854c0[Keyword:0] Line 3 Column 15 File C:/temp/Person.java)';' | )field_declaration | )class_body_declaration | )class_body_declarations | (class_body_declaration@Java~Java1_6=117#4885c40 Line 4 Column 5 File C:/temp/Person.java | (method_declaration@Java~Java1_6=135#4885c00 Line 4 Column 5 File C:/temp/Person.java | (method_modifiers@Java~Java1_6=141#4885700 Line 4 Column 5 File C:/temp/Person.java | |(method_modifiers@Java~Java1_6=142#4884e40 Line 4 Column 5 File C:/temp/Person.java)method_modifiers | |(method_modifier@Java~Java1_6=147#48856a0 Line 4 Column 5 File C:/temp/Person.java | | ('public'@Java~Java1_6=453#48853a0[Keyword:0] Line 4 Column 5 File C:/temp/Person.java)'public' | |)method_modifier | )method_modifiers | (type_parameters@Java~Java1_6=408#4885740 Line 4 Column 12 File C:/temp/Person.java)type_parameters | (type@Java~Java1_6=191#4885900 Line 4 Column 12 File C:/temp/Person.java | |(name@Java~Java1_6=406#48852a0 Line 4 Column 12 File C:/temp/Person.java | | (IDENTIFIER@Java~Java1_6=447#4885660[`String'] Line 4 Column 12 File C:/temp/Person.java)IDENTIFIER | | (type_arguments@Java~Java1_6=407#48851a0 Line 4 Column 19 File C:/temp/Person.java)type_arguments | |)name | |(brackets@Java~Java1_6=157#48858c0 Line 4 Column 19 File C:/temp/Person.java)brackets | )type | (IDENTIFIER@Java~Java1_6=447#48855c0[`toString'] Line 4 Column 19 File C:/temp/Person.java)IDENTIFIER | (parameters@Java~Java1_6=158#48858e0 Line 4 Column 27 File C:/temp/Person.java | |('('@Java~Java1_6=450#4885840[Keyword:0] Line 4 Column 27 File C:/temp/Person.java)'(' | |(')'@Java~Java1_6=451#4885620[Keyword:0] Line 4 Column 28 File C:/temp/Person.java)')' | )parameters | (brackets@Java~Java1_6=157#4885060 Line 5 Column 7 File C:/temp/Person.java)brackets | (block@Java~Java1_6=217#4885be0 Line 5 Column 7 File C:/temp/Person.java | |('{'@Java~Java1_6=448#48851c0[Keyword:0] Line 5 Column 7 File C:/temp/Person.java)'{' | |(statement_sequence@Java~Java1_6=218#4885ba0 Line 5 Column 9 File C:/temp/Person.java | | (statement_sequence_member@Java~Java1_6=223#4885b80 Line 5 Column 9 File C:/temp/Person.java | | (executable_statement@Java~Java1_6=243#4885b60 Line 5 Column 9 File C:/temp/Person.java | | ('return'@Java~Java1_6=491#4884f60[Keyword:0] Line 5 Column 9 File C:/temp/Person.java)'return' | | (expression@Java~Java1_6=332#4885ac0 Line 5 Column 16 File C:/temp/Person.java | | |(conditional_expression@Java~Java1_6=345#4885a60 Line 5 Column 16 File C:/temp/Person.java | | | (conditional_or_expression@Java~Java1_6=347#4885a20 Line 5 Column 16 File C:/temp/Person.java | | | (conditional_and_expression@Java~Java1_6=349#48859e0 Line 5 Column 16 File C:/temp/Person.java | | | (inclusive_or_expression@Java~Java1_6=351#48857e0 Line 5 Column 16 File C:/temp/Person.java | | | |(exclusive_or_expression@Java~Java1_6=353#48855a0 Line 5 Column 16 File C:/temp/Person.java | | | | (and_expression@Java~Java1_6=355#4885940 Line 5 Column 16 File C:/temp/Person.java | | | | (equality_expression@Java~Java1_6=357#4885880 Line 5 Column 16 File C:/temp/Person.java | | | | (relational_expression@Java~Java1_6=360#4885800 Line 5 Column 16 File C:/temp/Person.java | | | | |(shift_expression@Java~Java1_6=366#48856c0 Line 5 Column 16 File C:/temp/Person.java | | | | | (additive_expression@Java~Java1_6=370#4885180 Line 5 Column 16 File C:/temp/Person.java | | | | | (multiplicative_expression@Java~Java1_6=373#4885780 Line 5 Column 16 File C:/temp/Person.java | | | | | (unary_expression@Java~Java1_6=383#4885600 Line 5 Column 16 File C:/temp/Person.java | | | | | |(unary_expression_not_plus_minus@Java~Java1_6=389#4885680 Line 5 Column 16 File C:/temp/Person.java | | | | | | (literal@Java~Java1_6=390#4884f80 Line 5 Column 16 File C:/temp/Person.java | | | | | | (STRING@Java~Java1_6=536#4885120[`name'] Line 5 Column 16 File C:/temp/Person.java)STRING | | | | | | )literal | | | | | |)unary_expression_not_plus_minus | | | | | )unary_expression | | | | | )multiplicative_expression | | | | | )additive_expression | | | | |)shift_expression | | | | )relational_expression | | | | )equality_expression | | | | )and_expression | | | |)exclusive_or_expression | | | )inclusive_or_expression | | | )conditional_and_expression | | | )conditional_or_expression | | |)conditional_expression | | )expression | | (';'@Java~Java1_6=440#48856e0[Keyword:0] Line 5 Column 22 File C:/temp/Person.java)';' | | )executable_statement | | )statement_sequence_member | |)statement_sequence | |('}'@Java~Java1_6=449#4885b40[Keyword:0] Line 5 Column 28 File C:/temp/Person.java)'}' | )block | )method_declaration | )class_body_declaration |)class_body_declarations |('}'@Java~Java1_6=449#4885bc0[Keyword:0] Line 6 Column 1 File C:/temp/Person.java)'}' )class_body )type_declaration )type_declarations (optional_CONTROL_Z@Java~Java1_6=5#4885ce0 Line 7 Column 1 File C:/temp/Person.java)optional_CONTROL_Z )compilation_unit
这是AST（由CST自动生成的DMS）：
(compilation_unit@Java~Java1_6=1#486f900^0 Line 1 Column 1 File C:/temp/Person.java (type_declarations@Java~Java1_6=15#486f4c0 {1} Line 1 Column 1 File C:/temp/Person.java (type_declaration@Java~Java1_6=17#486f5e0 Line 1 Column 1 File C:/temp/Person.java (type_class_modifiers@Java~Java1_6=77#486eda0 Line 1 Column 1 File C:/temp/Person.java)type_class_modifiers (class_header@Java~Java1_6=89#486ee60 Line 1 Column 1 File C:/temp/Person.java |(IDENTIFIER@Java~Java1_6=447#486ede0[`Person'] Line 1 Column 7 File C:/temp/Person.java)IDENTIFIER |(type_parameters@Java~Java1_6=408#486ee20 Line 1 Column 14 File C:/temp/Person.java)type_parameters )class_header (class_body@Java~Java1_6=94#486f040 Line 1 Column 14 File C:/temp/Person.java |(class_body_declarations@Java~Java1_6=111#486ee40 {3} Line 2 Column 5 File C:/temp/Person.java | (class_body_declaration@Java~Java1_6=118#486f300 Line 2 Column 5 File C:/temp/Person.java | (field_declaration@Java~Java1_6=168#486f380 Line 2 Column 5 File C:/temp/Person.java | (field_modifiers@Java~Java1_6=170#486eec0 Line 2 Column 5 File C:/temp/Person.java)field_modifiers | (type@Java~Java1_6=191#486f240 Line 2 Column 5 File C:/temp/Person.java | |(name@Java~Java1_6=406#486f180 Line 2 Column 5 File C:/temp/Person.java | | (IDENTIFIER@Java~Java1_6=447#486eea0[`String'] Line 2 Column 5 File C:/temp/Person.java)IDENTIFIER | | (type_arguments@Java~Java1_6=407#486f0e0 Line 2 Column 12 File C:/temp/Person.java)type_arguments | |)name | |(brackets@Java~Java1_6=157#486f200 Line 2 Column 12 File C:/temp/Person.java)brackets | )type | (variable_declarator@Java~Java1_6=181#486ef20 Line 2 Column 12 File C:/temp/Person.java | |(variable_declarator_id@Java~Java1_6=167#486efe0 Line 2 Column 12 File C:/temp/Person.java | | (IDENTIFIER@Java~Java1_6=447#486f0c0[`name'] Line 2 Column 12 File C:/temp/Person.java)IDENTIFIER | | (brackets@Java~Java1_6=157#486f060 Line 2 Column 16 File C:/temp/Person.java)brackets | |)variable_declarator_id | )variable_declarator | )field_declaration | )class_body_declaration | (class_body_declaration@Java~Java1_6=118#486f000 Line 3 Column 5 File C:/temp/Person.java | (field_declaration@Java~Java1_6=168#486f320 Line 3 Column 5 File C:/temp/Person.java | (field_modifiers@Java~Java1_6=170#486f2a0 Line 3 Column 5 File C:/temp/Person.java)field_modifiers | (type@Java~Java1_6=192#486eee0 Line 3 Column 5 File C:/temp/Person.java | |(primitive_type@Java~Java1_6=198#486ef60 Line 3 Column 5 File C:/temp/Person.java)primitive_type | |(brackets@Java~Java1_6=157#486ee00 Line 3 Column 12 File C:/temp/Person.java)brackets | )type | (variable_declarator@Java~Java1_6=181#486f2c0 Line 3 Column 12 File C:/temp/Person.java | |(variable_declarator_id@Java~Java1_6=167#486f3a0 Line 3 Column 12 File C:/temp/Person.java | | (IDENTIFIER@Java~Java1_6=447#486f120[`age'] Line 3 Column 12 File C:/temp/Person.java)IDENTIFIER | | (brackets@Java~Java1_6=157#486ef00 Line 3 Column 15 File C:/temp/Person.java)brackets | |)variable_declarator_id | )variable_declarator | )field_declaration | )class_body_declaration | (class_body_declaration@Java~Java1_6=117#486f7a0 Line 4 Column 5 File C:/temp/Person.java | (method_declaration@Java~Java1_6=135#486f480 Line 4 Column 5 File C:/temp/Person.java | (method_modifiers@Java~Java1_6=141#486f460 {1} Line 4 Column 5 File C:/temp/Person.java | |(method_modifier@Java~Java1_6=147#486f400 Line 4 Column 5 File C:/temp/Person.java)method_modifier | )method_modifiers | (type_parameters@Java~Java1_6=408#486f540 Line 4 Column 12 File C:/temp/Person.java)type_parameters | (type@Java~Java1_6=191#486f740 Line 4 Column 12 File C:/temp/Person.java | |(name@Java~Java1_6=406#486f620 Line 4 Column 12 File C:/temp/Person.java | | (IDENTIFIER@Java~Java1_6=447#486f080[`String'] Line 4 Column 12 File C:/temp/Person.java)IDENTIFIER | | (type_arguments@Java~Java1_6=407#486f640 Line 4 Column 19 File C:/temp/Person.java)type_arguments | |)name | |(brackets@Java~Java1_6=157#486f700 Line 4 Column 19 File C:/temp/Person.java)brackets | )type | (IDENTIFIER@Java~Java1_6=447#486f140[`toString'] Line 4 Column 19 File C:/temp/Person.java)IDENTIFIER | (parameters@Java~Java1_6=158#486f760 Line 4 Column 27 File C:/temp/Person.java)parameters | (brackets@Java~Java1_6=157#486f820 Line 5 Column 7 File C:/temp/Person.java)brackets | (block@Java~Java1_6=217#486f780 Line 5 Column 7 File C:/temp/Person.java | |(statement_sequence@Java~Java1_6=218#486f6e0 Line 5 Column 9 File C:/temp/Person.java | | (statement_sequence_member@Java~Java1_6=223#486f6c0 Line 5 Column 9 File C:/temp/Person.java | | (executable_statement@Java~Java1_6=243#486f6a0 Line 5 Column 9 File C:/temp/Person.java | | (unary_expression_not_plus_minus@Java~Java1_6=389#486f720 Line 5 Column 16 File C:/temp/Person.java | | |(literal@Java~Java1_6=390#486f280 Line 5 Column 16 File C:/temp/Person.java | | | (STRING@Java~Java1_6=536#486f160[`name'] Line 5 Column 16 File C:/temp/Person.java)STRING | | |)literal | | )unary_expression_not_plus_minus | | )executable_statement | | )statement_sequence_member | |)statement_sequence | )block | )method_declaration | )class_body_declaration |)class_body_declarations )class_body )type_declaration )type_declarations (optional_CONTROL_Z@Java~Java1_6=5#486f4e0 Line 7 Column 1 File C:/temp/Person.java)optional_CONTROL_Z )compilation_unit
编辑2015年3月： 这里是一些C ++ AST例子的链接
编辑2015年5月：DMS也一直做Java 1.7和1.8。
看一下Eclipse JDT AST的实现。
作为第一个介绍，你也可以阅读本教程 。
