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      1 /*
      2  * Copyright (C) 2017 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package parser.files
     18 
     19 import lexer.Token
     20 import lexer.TokenCategory
     21 import lexer.TokenGrammar
     22 import java.text.ParseException
     23 
     24 data class PackageInfo(val name: String, val version: Float)
     25 
     26 /**
     27  * Find and parse package info. Throw error if it can't find a valid declarationParser format.
     28  * Example format: package android.hardware.audio (at) 2.0;
     29  */
     30 fun parsePackageInfo(tokens: List<Token>): PackageInfo {
     31     val iter: ListIterator<Token> = tokens.listIterator()
     32     var token: Token
     33 
     34     while (iter.hasNext()) {
     35         token = iter.next()
     36 
     37         if (token.identifier == TokenGrammar.PACKAGE) {
     38             //collect namespace
     39             val pkgNameToks = mutableListOf<Token>()
     40             while (iter.hasNext()) {
     41                 token = iter.next()
     42                 if (token.identifier != TokenGrammar.AT && token.identifier != TokenGrammar.SEMICOLON) {
     43                     pkgNameToks.add(token)
     44                 } else {
     45                     break
     46                 }
     47             }
     48             val pkgName = pkgNameToks.map { it.value }.joinToString("")
     49 
     50             //step through format and test syntax
     51             if (token.identifier != TokenGrammar.AT) break
     52             token = iter.next()
     53             if (token.category != TokenCategory.Number) break //version
     54             val pkgVer = token.value.toFloat()
     55             token = iter.next()
     56             if (token.identifier != TokenGrammar.SEMICOLON) break
     57 
     58             //hooray, a proper package format
     59             return PackageInfo(pkgName, pkgVer)
     60         }
     61     }
     62     throw ParseException("Unable to find a valid package declaration", 0)
     63 }