contrib/jwrapper/src/code_generator.nit

   1 # This file is part of NIT (http://www.nitlanguage.org).
   2 #
   3 # Copyright 2014 Frédéric Vachon <fredvac@gmail.com>
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 # Services to generate extern class `in "Java"`
  18 module code_generator
  19
  20 intrude import types
  21
  22 class CodeGenerator
  23
  24         var with_attributes: Bool
  25         var comment_unknown_types: Bool
  26         var file_out: OFStream
  27         var java_class: JavaClass
  28         var nb_params: Int
  29         var module_name: String
  30         fun code_warehouse: CodeWarehouse do return once new CodeWarehouse
  31
  32         init (file_name: String, jclass: JavaClass, with_attributes, comment: Bool)
  33         do
  34                 file_out = new OFStream.open(file_name)
  35                 module_name = file_name.substring(0, file_name.search(".nit").from)
  36                 self.java_class = jclass
  37                 self.with_attributes = with_attributes
  38                 self.comment_unknown_types = comment
  39         end
  40
  41         fun generate
  42         do
  43                 var jclass = self.java_class
  44
  45                 var class_content = new Array[String]
  46                 class_content.add(gen_class_header(jclass.class_type))
  47
  48                 if with_attributes then
  49                         for id, jtype in jclass.attributes do class_content.add(gen_attribute(id, jtype))
  50                 end
  51
  52                 for id, methods_info in jclass.methods do
  53                         for method_info in methods_info do
  54                                 var nid = id
  55                                 if methods_info.length > 1 then nid += "{methods_info.index_of(method_info)}"
  56                                 class_content.add gen_method(id, nid, method_info.return_type, method_info.params)
  57                         end
  58                 end
  59                 class_content.add("\nend\n")
  60
  61                 var wrappers = new Array[String]
  62                 for jtype in jclass.unknown_types do
  63                         if jtype == jclass.class_type then continue
  64                         wrappers.add("\n")
  65                         wrappers.add(gen_unknown_class_header(jtype))
  66                 end
  67
  68                 var imports = new Array[String]
  69                 imports.add("import mnit_android\n")
  70                 for import_ in jclass.imports do
  71                         imports.add("import android::{import_}\n")
  72                 end
  73
  74                 file_out.write(gen_licence)
  75                 file_out.write("module {module_name}\n")
  76                 file_out.write(imports.join(""))
  77                 file_out.write("\n")
  78                 file_out.write(class_content.join(""))
  79                 file_out.write(wrappers.join(""))
  80         end
  81
  82         fun gen_licence: String
  83         do
  84                 return """# This file is part of NIT (http://www.nitlanguage.org).
  85 #
  86 # Copyright [Year] [Author name] <Author e-mail>
  87 #
  88 # Licensed under the Apache License, Version 2.0 (the "License");
  89 # you may not use this file except in compliance with the License.
  90 # You may obtain a copy of the License at
  91 #
  92 #     http://www.apache.org/licenses/LICENSE-2.0
  93 #
  94 # Unless required by applicable law or agreed to in writing, software
  95 # distributed under the License is distributed on an "AS IS" BASIS,
  96 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  97 # See the License for the specific language governing permissions and
  98 # limitations under the License.
  99
 100 # This code has been generated using `javap`
 101 """
 102         end
 103
 104         fun gen_class_header(jtype: JavaType): String
 105         do
 106                 var temp = new Array[String]
 107                 temp.add("extern class Native{jtype.id} in \"Java\" `\{ {jtype} `\}\n")
 108                 temp.add("\tsuper JavaObject\n\n")
 109
 110                 return temp.join("")
 111         end
 112
 113         fun gen_unknown_class_header(jtype: JavaType): String
 114         do
 115                 var nit_type: NitType
 116                 if jtype.extern_name.has_generic_params then
 117                         nit_type = jtype.extern_name.generic_params.first
 118                 else
 119                         nit_type = jtype.extern_name
 120                 end
 121
 122                 var temp = new Array[String]
 123                 temp.add("extern class {nit_type} in \"Java\" `\{ {jtype.to_package_name} `\}\n")
 124                 temp.add("\tsuper JavaObject\n\nend\n")
 125
 126                 return temp.join("")
 127         end
 128
 129         fun gen_attribute(jid: String, jtype: JavaType): String
 130         do
 131                 return "\tvar {jid.to_nit_method_name}: {jtype.to_nit_type}\n"
 132         end
 133
 134         fun gen_method(jmethod_id: String, nmethod_id: String, jreturn_type: JavaType, jparam_list: Array[JavaType]): String
 135         do
 136                 var java_params = ""
 137                 var nit_params  = ""
 138                 var nit_id = "arg"
 139                 var nit_id_no = 0
 140                 var nit_types = new Array[NitType]
 141                 var comment = ""
 142
 143                 # Parameters
 144                 for i in [0..jparam_list.length[ do
 145                         var jparam = jparam_list[i]
 146                         var nit_type = jparam.to_nit_type
 147
 148                         if not nit_type.is_complete then
 149                                 if jparam.is_wrapped then
 150                                         java_class.imports.add nit_type.mod.as(not null)
 151                                 else
 152                                         if comment_unknown_types then
 153                                                 comment = "#"
 154                                         else
 155                                                 nit_type = jparam.extern_name
 156                                                 java_class.unknown_types.add(jparam)
 157                                         end
 158                                 end
 159                         end
 160
 161                         var cast = ""
 162
 163                         if not jparam.is_collection then cast = jparam.param_cast
 164
 165                         nit_types.add(nit_type)
 166                         nit_type.arg_id = "{nit_id}{nit_id_no}"
 167
 168                         if i == jparam_list.length - 1 then
 169                                 java_params += "{cast}{nit_id}{nit_id_no}"
 170                                 nit_params  += "{nit_id}{nit_id_no}: {nit_type}"
 171                         else
 172                                 java_params += "{cast}{nit_id}{nit_id_no}" + ", "
 173                                 nit_params  += "{nit_id}{nit_id_no}: {nit_type}, "
 174                         end
 175
 176                         nit_id_no += 1
 177                 end
 178
 179                 # Method identifier
 180                 var method_id = nmethod_id.to_nit_method_name
 181                 var nit_signature = new Array[String]
 182
 183                 nit_signature.add "\tfun {method_id}"
 184
 185                 if not jparam_list.is_empty then
 186                         nit_signature.add "({nit_params})"
 187                 end
 188
 189                 var return_type = null
 190
 191                 if not jreturn_type.is_void then
 192                         return_type = jreturn_type.to_nit_type
 193
 194                         if not return_type.is_complete then
 195                                 if jreturn_type.is_wrapped then
 196                                         java_class.imports.add return_type.mod.as(not null)
 197                                 else
 198                                         if comment_unknown_types then
 199                                                 comment = "#"
 200                                         else
 201                                                 return_type = jreturn_type.extern_name
 202                                                 java_class.unknown_types.add(jreturn_type)
 203                                         end
 204                                 end
 205                         end
 206
 207                         nit_signature.add ": {return_type} "
 208                 end
 209
 210                 var temp = new Array[String]
 211
 212                 temp.add(comment + nit_signature.join(""))
 213
 214                 # FIXME : This huge `if` block is only necessary to copy primitive arrays as long as there's no better way to do it
 215                 if comment == "#" then
 216                         temp.add(" in \"Java\" `\{\n{comment}\t\trecv.{jmethod_id}({java_params});\n{comment}\t`\}\n")
 217                 # Methods with return type
 218                 else if return_type != null then
 219                         temp.add(" in \"Java\" `\{\n{comment}\t\treturn {jreturn_type.return_cast} recv.{jmethod_id}({java_params});\n{comment}\t`\}\n")
 220                 # Methods without return type
 221                 else if jreturn_type.is_void then
 222                         temp.add(" in \"Java\" `\{\n{comment}\t\trecv.{jmethod_id}({java_params});\n{comment}\t`\}\n")
 223                 # No copy
 224                 else
 225                         temp.add(" in \"Java\" `\{\n{comment}\t\trecv.{jmethod_id}({java_params});\n{comment}\t`\}\n")
 226                 end
 227
 228                 return temp.join("")
 229         end
 230 end
 231
 232 # Contains raw code mostly used to copy collections
 233 class CodeWarehouse
 234
 235         private fun create_imports(nit_type: NitType, is_param: Bool): String
 236         do
 237                 var imports = ""
 238                 var ntype = nit_type.to_s
 239                 var gen_type = nit_type.generic_params.join(", ")
 240
 241                 if not is_param then
 242                         if nit_type.is_map then
 243                                 imports = """ import {{{ntype}}}, {{{ntype}}}.[]="""
 244                         else
 245                                 imports = """ import {{{ntype}}}, {{{ntype}}}.add"""
 246                         end
 247                 else if nit_type.id == "Array" then
 248                         imports = """ import {{{ntype}}}, {{{ntype}}}.length, {{{ntype}}}.[]"""
 249                 else if nit_type.is_map then
 250                         imports = """ import {{{ntype}}}.iterator, Iterator[{{{gen_type}}}].is_ok, Iterator[{{{gen_type}}}].next, Iterator[{{{gen_type}}}].item, Iterator[{{{gen_type}}}].key"""
 251                 else
 252                         imports = """ import {{{ntype}}}.iterator, Iterator[{{{gen_type}}}].is_ok, Iterator[{{{gen_type}}}].next, Iterator[{{{gen_type}}}].item"""
 253                 end
 254
 255                 return imports
 256         end
 257 end
 258
 259 redef class String
 260         # Convert the Java method name `self` to the Nit style
 261         #
 262         # * Converts to snake case
 263         # * Strips `Get` and `Set`
 264         # * Add suffix `=` to setters
 265         fun to_nit_method_name: String
 266         do
 267                 var name
 268                 if self.has_prefix("Get") then
 269                         name = self.substring_from(3)
 270                 else if self.has_prefix("Set") then
 271                         name = self.substring_from(3)
 272                         name += "="
 273                 else
 274                         name = self
 275                 end
 276
 277                 return name.to_snake_case
 278         end
 279 end