DrJava Test Coverage (drjava-20120422-r5456)

Clover coverage report - DrJava Test Coverage (drjava-20120422-r5456)

Coverage timestamp: Sun Apr 22 2012 03:13:25 CDT

FRAMES NO FRAMES

file stats:	LOC:	215		Methods:	11
	NCLOC:	104		Classes:	3

Source file

Conditionals

Statements

Methods

TOTAL

SExpParser.java

75%

91.3%

100%

88.3%

1		/*BEGIN_COPYRIGHT_BLOCK
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36
37		package edu.rice.cs.util.sexp;
38
39		import java.io.File;
40		import java.io.Reader;
41		import java.io.FileReader;
42		import java.io.StringReader;
43		import java.io.IOException;
44		import java.util.List;
45		import java.util.ArrayList;
46		import java.util.LinkedList;
47
48		/**
49		* This parser is not meant to be instantiated. It has
50		* static methods that do all the work for you. These
51		* parse methods take in the data that is to be parsed
52		* and simply returns an s-expression abstract syntax.
53		* @author Jonathan Lugo, PLT Group
54		*/
55		public class SExpParser {
56
57	9	public static List<SEList> parse(File f) throws SExpParseException, IOException{
58	9	return parse(new FileReader(f));
59		}
60
61	12	public static List<SEList> parse(String s) throws SExpParseException {
62	12	return parse(new StringReader(s));
63		}
64
65	22	public static List<SEList> parse(Reader r) throws SExpParseException {
66	22	try {
67	22	return new ParseHelper(r).parseMultiple();
68		}
69		catch(LexingException e) {
70	0	throw new SExpParseException(e.getMessage());
71		}
72		catch(PrivateParseException e) {
73	8	throw new SExpParseException(e.getMessage());
74		}
75		}
76
77		/** A new helper is instantiated for each time
78		* the user wants to parse data. This is not
79		* reused. The instances of the ParseHelpers are
80		* handled solely in the outer class SExpParser.
81		*/
82		private static class ParseHelper {
83
84		private Lexer _lex;
85
86	22	public ParseHelper(Reader r) {
87	22	_lex = new Lexer(r);
88		}
89
90		/**
91		* Parse a forest of top-level s-expressions from {@link #parseTopLevelExp()}.
92		* @see #parseTopLevelExp()
93		*/
94	22	public List<SEList> parseMultiple() {
95	22	ArrayList<SEList> l = new ArrayList<SEList>();
96	22	SEList exp;
97	?	while ( (exp = parseTopLevelExp()) != null) {
98	55	l.add(exp);
99		}
100	14	return l;
101		}
102
103		/**
104		* A top-level s-expression is simply a non-empty list. Our s-expression files
105		* can be a forest of several trees, but the Atomic values are not allowed
106		* at the top level, only lists.
107		* @return the top-level list s-expression
108		*/
109	77	public SEList parseTopLevelExp() {
110	77	Tokens.SExpToken t = _lex.readToken();
111	77	if (t == Tokens.LeftParenToken.ONLY) {
112	59	return parseList();
113		}
114	18	else if (t == null) {
115	14	return null;
116		}
117		else {
118	4	throw new PrivateParseException("A top-level s-expression must be a list. " +
119		"Invalid start of list: " + t);
120		}
121		}
122
123		/**
124		* Parses the next s-expression in the lexer's buffer.
125		* This may be either a cons or an atom
126		* @return the next s-expression in the read buffer.
127		*/
128	808	public SExp parseExp() {
129	808	Tokens.SExpToken t = _lex.readToken();
130	808	assertNotEOF(t);
131	805	if (t == Tokens.LeftParenToken.ONLY) {
132	254	return parseList();
133		}
134		else {
135	551	return parseAtom(t);
136		}
137		}
138
139		/**
140		* The left paren has already been read. This starts
141		* building up the recursive list structure
142		* @return the parsed recursive s-expression list
143		*/
144	313	private SEList parseList() {
145	313	LinkedList<SExp> list = new LinkedList<SExp>();
146	313	Tokens.SExpToken t = _lex.peek();
147	313	assertNotEOF(t);
148
149	312	while (t != Tokens.RightParenToken.ONLY) {
150	808	list.addFirst(parseExp());
151	805	t = _lex.peek();
152		}
153
154		// t has to be a Tokens.RightParenToken at this point.
155		// simply eat the token
156	309	_lex.readToken();
157
158		// Compile the cons structure from the list of exps
159	309	SEList cons = Empty.ONLY;
160	309	for (SExp exp : list) {
161	801	cons = new Cons(exp, cons);
162		}
163	309	return cons;
164		}
165
166		/**
167		* Parses an atom. The token was already read and
168		* found not to start a list, this method interprets
169		* what is given. This method chooses which type of
170		* atom the token represents and creates the atom.
171		* @param t the token to interpret
172		* @return the correct corresponding atom
173		*/
174	551	private Atom parseAtom(Tokens.SExpToken t) {
175	551	if (t instanceof Tokens.BooleanToken) {
176	0	if (((Tokens.BooleanToken)t).getValue())
177	0	return BoolAtom.TRUE;
178		else
179	0	return BoolAtom.FALSE;
180		}
181	551	else if (t instanceof Tokens.NumberToken) {
182	114	return new NumberAtom(((Tokens.NumberToken)t).getValue());
183		}
184	437	else if (t instanceof Tokens.QuotedTextToken) {
185	122	return new QuotedTextAtom(t.getText());
186		}
187		else {
188	315	return new TextAtom(t.getText());
189		}
190		}
191
192		/**
193		* Throws the EOF exception if the given token is the end of file
194		* @param t the token to check
195		*/
196	1121	private void assertNotEOF(Tokens.SExpToken t) {
197	1121	if (t == null) {
198	4	throw new PrivateParseException("Unexpected <EOF> at line " + _lex.lineno());
199		}
200		}
201		}
202
203		/** This runtime exception makes it easier to write the parser since
204		* the methods of the helper class won't need to constantly declare
205		* the SExpParseException to be thrown.
206		*/
207		private static class PrivateParseException extends RuntimeException {
208		/**
209		* Creates a runtime exception with the message that is desired for
210		* the eventual checked exception
211		* @param msg the message to display
212		*/
213	8	public PrivateParseException(String msg) { super(msg); }
214		}
215		}