.TH "Ast_iterator" 3 2024-05-31 OCamldoc "OCaml library"
.SH NAME
Ast_iterator \- Ast_iterator.iterator enables AST inspection using open recursion.
.SH Module
Module   Ast_iterator
.SH Documentation
.sp
Module
.BI "Ast_iterator"
 : 
.B sig end

.sp

.ft B
Ast_iterator\&.iterator
.ft R
enables AST inspection using open recursion\&.  A
typical mapper would be based on 
.ft B
Ast_iterator\&.default_iterator
.ft R
, a
trivial iterator, and will fall back on it for handling the syntax it does
not modify\&.
.sp
Warning: this module is unstable and part of
.ft B
Compiler_libs
.ft R
\&.

.sp

.sp
.sp

.PP
.SS A generic Parsetree iterator

.PP
.I type iterator 
= {
 attribute : 
.B iterator -> Parsetree.attribute -> unit
;
 attributes : 
.B iterator -> Parsetree.attribute list -> unit
;
 binding_op : 
.B iterator -> Parsetree.binding_op -> unit
;
 case : 
.B iterator -> Parsetree.case -> unit
;
 cases : 
.B iterator -> Parsetree.case list -> unit
;
 class_declaration : 
.B iterator -> Parsetree.class_declaration -> unit
;
 class_description : 
.B iterator -> Parsetree.class_description -> unit
;
 class_expr : 
.B iterator -> Parsetree.class_expr -> unit
;
 class_field : 
.B iterator -> Parsetree.class_field -> unit
;
 class_signature : 
.B iterator -> Parsetree.class_signature -> unit
;
 class_structure : 
.B iterator -> Parsetree.class_structure -> unit
;
 class_type : 
.B iterator -> Parsetree.class_type -> unit
;
 class_type_declaration : 
.B iterator -> Parsetree.class_type_declaration -> unit
;
 class_type_field : 
.B iterator -> Parsetree.class_type_field -> unit
;
 constructor_declaration : 
.B iterator -> Parsetree.constructor_declaration -> unit
;
 directive_argument : 
.B iterator -> Parsetree.directive_argument -> unit
;
 expr : 
.B iterator -> Parsetree.expression -> unit
;
 extension : 
.B iterator -> Parsetree.extension -> unit
;
 extension_constructor : 
.B iterator -> Parsetree.extension_constructor -> unit
;
 include_declaration : 
.B iterator -> Parsetree.include_declaration -> unit
;
 include_description : 
.B iterator -> Parsetree.include_description -> unit
;
 label_declaration : 
.B iterator -> Parsetree.label_declaration -> unit
;
 location : 
.B iterator -> Location.t -> unit
;
 module_binding : 
.B iterator -> Parsetree.module_binding -> unit
;
 module_declaration : 
.B iterator -> Parsetree.module_declaration -> unit
;
 module_substitution : 
.B iterator -> Parsetree.module_substitution -> unit
;
 module_expr : 
.B iterator -> Parsetree.module_expr -> unit
;
 module_type : 
.B iterator -> Parsetree.module_type -> unit
;
 module_type_declaration : 
.B iterator -> Parsetree.module_type_declaration -> unit
;
 open_declaration : 
.B iterator -> Parsetree.open_declaration -> unit
;
 open_description : 
.B iterator -> Parsetree.open_description -> unit
;
 pat : 
.B iterator -> Parsetree.pattern -> unit
;
 payload : 
.B iterator -> Parsetree.payload -> unit
;
 signature : 
.B iterator -> Parsetree.signature -> unit
;
 signature_item : 
.B iterator -> Parsetree.signature_item -> unit
;
 structure : 
.B iterator -> Parsetree.structure -> unit
;
 structure_item : 
.B iterator -> Parsetree.structure_item -> unit
;
 toplevel_directive : 
.B iterator -> Parsetree.toplevel_directive -> unit
;
 toplevel_phrase : 
.B iterator -> Parsetree.toplevel_phrase -> unit
;
 typ : 
.B iterator -> Parsetree.core_type -> unit
;
 row_field : 
.B iterator -> Parsetree.row_field -> unit
;
 object_field : 
.B iterator -> Parsetree.object_field -> unit
;
 type_declaration : 
.B iterator -> Parsetree.type_declaration -> unit
;
 type_extension : 
.B iterator -> Parsetree.type_extension -> unit
;
 type_exception : 
.B iterator -> Parsetree.type_exception -> unit
;
 type_kind : 
.B iterator -> Parsetree.type_kind -> unit
;
 value_binding : 
.B iterator -> Parsetree.value_binding -> unit
;
 value_description : 
.B iterator -> Parsetree.value_description -> unit
;
 with_constraint : 
.B iterator -> Parsetree.with_constraint -> unit
;
 }

.sp
A 
.ft B
iterator
.ft R
record implements one "method" per syntactic category,
using an open recursion style: each method takes as its first
argument the iterator to be applied to children in the syntax
tree\&.

.sp

.I val default_iterator 
: 
.B iterator
.sp
A default iterator, which implements a "do not do anything" mapping\&.

.sp