diff options
Diffstat (limited to 'java/demo/book/map_filesystem/Grammar.java')
| -rw-r--r-- | java/demo/book/map_filesystem/Grammar.java | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/java/demo/book/map_filesystem/Grammar.java b/java/demo/book/map_filesystem/Grammar.java new file mode 100644 index 00000000000..92da79a56d0 --- /dev/null +++ b/java/demo/book/map_filesystem/Grammar.java @@ -0,0 +1,202 @@ +// ********************************************************************** +// +// Copyright (c) 2003-2008 ZeroC, Inc. All rights reserved. +// +// This copy of Ice is licensed to you under the terms described in the +// ICE_LICENSE file included in this distribution. +// +// ********************************************************************** + +class Grammar +{ + Grammar(Parser p) + { + _parser = p; + _scanner = new Scanner(_parser); + } + + void + parse() + { + while(true) + { + try + { + _token = _scanner.nextToken(); + if(_token == null) + { + return; + } + else if(_token.type == Token.TOK_SEMI) + { + // Continue + } + else if(_token.type == Token.TOK_HELP) + { + _token = _scanner.nextToken(); + if(_token.type != Token.TOK_SEMI) + { + throw new ParseError("Expected ';'"); + } + _parser.usage(); + } + else if(_token.type == Token.TOK_EXIT) + { + _token = _scanner.nextToken(); + if(_token.type != Token.TOK_SEMI) + { + throw new ParseError("Expected ';'"); + } + return; + } + else if(_token.type == Token.TOK_LIST) + { + _token = _scanner.nextToken(); + if(_token.type != Token.TOK_SEMI) + { + throw new ParseError("Expected ';'"); + } + _parser.list(false); + } + else if(_token.type == Token.TOK_LIST_RECURSIVE) + { + _token = _scanner.nextToken(); + if(_token.type != Token.TOK_SEMI) + { + throw new ParseError("Expected ';'"); + } + _parser.list(true); + } + else if(_token.type == Token.TOK_CREATE_FILE) + { + java.util.List<String> s = strings(); + if(_token.type != Token.TOK_SEMI) + { + throw new ParseError("Expected ';'"); + } + if(s.size() == 0) + { + throw new ParseError("usage: mkfile FILE [FILE...]"); + } + _parser.createFile(s); + } + else if(_token.type == Token.TOK_CREATE_DIR) + { + java.util.List<String> s = strings(); + if(_token.type != Token.TOK_SEMI) + { + throw new ParseError("Expected ';'"); + } + if(s.size() == 0) + { + throw new ParseError("usage: mkdir DIR [DIR...]"); + } + _parser.createDir(s); + } + else if(_token.type == Token.TOK_PWD) + { + _token = _scanner.nextToken(); + if(_token.type != Token.TOK_SEMI) + { + throw new ParseError("Expected ';'"); + } + _parser.pwd(); + } + else if(_token.type == Token.TOK_CD) + { + java.util.List<String> s = strings(); + if(_token.type != Token.TOK_SEMI) + { + throw new ParseError("Expected ';'"); + } + if(s.size() > 1) + { + throw new ParseError("usage: cd [DIR]"); + } + else if(s.size() == 0) + { + _parser.cd("/"); + } + else + { + _parser.cd((String)s.get(0)); + } + } + else if(_token.type == Token.TOK_CAT) + { + java.util.List<String> s = strings(); + if(_token.type != Token.TOK_SEMI) + { + throw new ParseError("Expected ';'"); + } + if(s.size() != 1) + { + throw new ParseError("usage: cat FILE"); + } + _parser.cat((String)s.get(0)); + } + else if(_token.type == Token.TOK_WRITE) + { + java.util.LinkedList<String> s = strings(); + if(_token.type != Token.TOK_SEMI) + { + throw new ParseError("Expected ';'"); + } + if(s.size() == 0) + { + throw new ParseError("usage: write FILE [STRING...]"); + } + _parser.write(s); + } + else if(_token.type == Token.TOK_RM) + { + java.util.List<String> s = strings(); + if(_token.type != Token.TOK_SEMI) + { + throw new ParseError("Expected ';'"); + } + if(s.size() == 0) + { + throw new ParseError("usage: rm NAME [NAME...]"); + } + _parser.destroy(s); + } + else + { + _parser.error("parse error"); + } + } + catch(ParseError e) + { + _parser.error("Parse error: " + e.getMessage()); + } + } + } + + private java.util.LinkedList<String> + strings() + { + java.util.LinkedList<String> l = new java.util.LinkedList<String>(); + while(true) + { + _token = _scanner.nextToken(); + if(_token.type != Token.TOK_STRING) + { + return l; + } + l.add(_token.value); + } + } + + static private class ParseError extends RuntimeException + { + ParseError(String msg) + { + super(msg); + } + } + + private Parser _parser; + private Scanner _scanner; + private Token _token; +} |