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## 14 Mk-Src Script

A good deal of interface code is automatically generated by the `mk-src.pl` Perl script. I am doing it this way to avoid having to write a lot of relative code for the C++ interface. This should also make adding interface for other languages a lot less tedious and will allow the interface to automatically take advantage of new Aspell functionality as it is made available. The `mk-src.pl` script uses `mk-src.in` as its input.

### 14.1 mk-src.in

NOTE: This section may not always be up to date since it is manually converted from the pod source.

The format of `mk-src.in` is as follows:

        The following characters are literals: { } / '\ ' \n = >

        <items>
        <items> := (<item>\n)+
        <items> := <category>:\ <name> {\n<details>\n} | <<tab>><details>
        <details> := <options>\n /\n <items>
        <options> := (<option>\n)*
        <option> := <key> [=> <value>]

        <<tab>> means everything should be indented by one tab

See MkSrc::Info for a description of the categories and options

### 14.2 MkSrc::Info

`%info`

The info array contains information on how to process the info in `mk-src.pl`. It has the following layout

        <catagory> => options => []
                      groups => [] # if undef than anything is accepted
                      creates_type => "" # the object will create a new type
                                         # as specified
                      proc => <impl type> => sub {}

where <impl type> is one of:

        cc: for "aspell.h" header file
        cxx: for C++ interface implemented on top of cc interface
        native: for creation of header files used internally by aspell
        impl: for defination of functions declared in cc interface.
              the definations use the native hedaer files
        native_impl: for implementations of stuff declared in the native
                      header files

each proc sub should take the following argv

        $data: a subtree of $master_data
        $accum:

<options> is one of:

        desc: description of the object
        prefix:
        posib err: the method may return an error condition
        c func:
        const: the method is a const member
        c only: only include in the external interface
        c impl headers: extra headers that need to be included in the C impl
        c impl: use this as the c impl instead of the default
        cxx impl: use this as the cxx impl instead of the default
        returns alt type: the constructor returns some type other than
          the object from which it is a member of
        no native: do not attemt to create a native implementation
        treat as object: treat as a object rather than a pointer

The `%info` structure is initialized as follows:

        our %info =
        (
         root => {
           options => [],
           groups => ['methods', 'group']},
         methods => {
           # methods is a collection of methods which will be inserted into
           # a class after some simple substation rules.  A $ will be
           # replaced with name of the class.
           options => ['strip', 'prefix', 'c impl headers'],
           groups => undef},
         group => {
           # a group is a colection of objects which should be grouped together
           # this generally means they will be in the same source file
           options => ['no native'],
           groups => ['enum', 'struct', 'union', 'func', 'class', 'errors']},
         enum => {
           # basic C enum
           options => ['desc', 'prefix'],
           creates_type => 'enum'},
         struct => {
           # basic c struct
           options => ['desc', 'treat as object'],
           groups => undef,
           creates_type => 'struct',},
         union => {
           # basic C union
           options => ['desc', 'treat as object'],
           groups => undef,
           creates_type => 'union'},
         class => {
           # C++ class
           options => ['c impl headers'],
           groups => undef,
           creates_type => 'class'},
         errors => {}, # possible errors
         method => {
           # A class method
           options => ['desc', 'posib err', 'c func', 'const',
                       'c only', 'c impl', 'cxx impl'],
           groups => undef},
         constructor => {
           # A class constructor
           options => ['returns alt type', 'c impl', 'desc'],
           groups => 'types'},
         destructor => {
           # A class destructor
           options => [],
           groups => undef},
         );

In addition to the categories listed above a “methods” category by be specified in under the class category. A “methods” category is created for each methods group under the name “<methods name> methods”. When groups is undefined a type name may be specified in place of a category.

`%types`

types contains a master list of all types. This includes basic types and ones created in `mk-src.in`. The basic types include:

        'void', 'bool', 'pointer', 'double',
        'string', 'encoded string', 'string obj',
        'char', 'unsigned char',
        'short', 'unsigned short',
        'int', 'unsigned int',
        'long', 'unsigned long'

%methods

`%methods` is used for holding the “methods” information

### 14.3 MkSrc::Util

This module contains various useful utility functions:

`false`
  Returns 0.
`true`
  Returns 1.
`cmap EXPR LIST`
  Apply EXPR to each item in LIST and than concatenate the result into a string
`one_of STR LIST`
  Returns true if LIST contains at least one of STR.
`to_upper STR`
  Convert STR to all uppercase and substitute spaces with underscores.
`to_lower STR`
  Convert STR to all lowercase and substitute spaces with underscores.
`to_mixed STR`
  Convert STR to mixed case where each new word startes with a uppercase letter. For example "feed me" would become "FeedMe".

### 14.4 MkSrc::Read

`read` Read in `mk-src.in` and return a data structure which has the following format:

          <tree>
          <tree> := <options>
                    data => <tree>
        where each tree represents an entry in mk-src.in.
        The following two options are always provided:
          name: the name of the entry
          type: the catagory or type name
        Additional options are the same as specified in %info

### 14.5 MKSrc::Create

`create_cc_file PARMS`
  Create a source file.

                     Required Parms: type, dir, name, data
                     Boolean Parms:  header, cxx
                     Optional Parms: namespace (required if cxx), pre_ext,
                                     accum

`create_file FILENAME DATA`
  Writes DATA to FILENAME but only if DATA differs from the content of the file and the string:

                     Automatically generated file.

  is present in the existing file if it already exists.

### 14.6 Code Generation Modes

The code generation modes are currently one of the following:

              cc:     Mode used to create types suitable for C interface
              cc_cxx: Like cc but typenames don't have a leading Aspell prefix
              cxx:    Mode used to create types suitable for CXX interface
              native: Mode in which types are suitable for the internal
                      implementation
              native_no_err: Like Native but with out PosibErr return types

### 14.7 MkSrc::CcHelper

Helper functions used by interface generation code:

             to_c_return_type ITEM
                 .

             c_error_cond ITEM
                 .

`make_func NAME @TYPES PARMS ; %ACCUM`
  Creates a function prototype

  Parms can be any of:

                          mode: code generation mode

`call_func NAME @TYPES PARMS ; %ACCUM`
  Return a string to call a func. Will prefix the function with return if the functions returns a non-void type;

  Parms can be any of:

                          mode: code generation mode

`to_type_name ITEM PARMS ; %ACCUM`
  Converts item into a type name.

  Parms can be any of:

                     mode: code generation mode
                     use_type: include the actual type
                     use_name: include the name on the type
                     pos: either "return" or "other"

`make_desc DESC ; LEVEL`
  Make a C comment out of DESC optionally indenting it LEVEL spaces.
`make_c_method CLASS ITEM PARMS ; %ACCUM`
  Create the phototype for a C method which is really a function.

  Parms is any of:

                     mode:      code generation mode
                     no_aspell: if true do not include aspell in the name
                     this_name: name for the parameter representing the
                                current object

`call_c_method CLASS ITEM PARMS ; %ACCUM`
  Like make_c_method but instead returns the appropriate string to call the function. If the function returns a non-void type the string will be prefixed with a return statement.
`form_c_method CLASS ITEM PARMS ; %ACCUM`
  Like make_c_method except that it returns the array:

                     ($func, $data, $parms, $accum)

  which is suitable for passing into make_func. It will return an empty array if it can not make a method from ITEM.

`make_cxx_method ITEM PARMS ; %ACCUM`
  Create the phototype for a C++ method.

  Parms is one of:

                     mode: code generation mode