Homework 01 (Due: Friday, February 16, 2018, 11 : 59 : 00PM Central Time)
CSCE 322
1 Instructions
In this assignment, you will be required to scan, parse, and check the semantics of a file that encodes the state of a variation of basic train Dominoes. The definition of a properly formatted input file is given in Section 1.1.
You will be submitting one .java file and two .g4 (ANTLR) files via web hand-in. 1.1 File Specification
• The file contains two (2) labeled sections: Trains and Hands . Each section is enclosed by start and end tags (<< and >>, respectively).
• Trains is a pound-separated (#) list of lists (the dominoes that an individual has played) that appear between { and } tokens. Valid dominoes are of the form [N,N] where N is an integer.
• Hands is a pound-separated (#) list of lists (the dominoes that an individual holds) that appear between { and } tokens. Valid dominoes are of the form [N,N] where N is an integer.
An example of a properly formatted file is shown in Figure 1.
<Trains <<
{[6,9] [9,9] } #
{ { { { { {
{ { { { { { {
>>
[0,1] [1,1] } # [2,11] [11,11] } #
[10 ,10] [5,5]
[4,4] [1,8]
>> <Hands
[10 ,12] } # [5,12] } #
[4,11] } # [8,8] }
<<
[3,7] [1,10] [2,5] [1,2] [4,5] [11,12] [5,7] [3,8] [0,12] [3,3] [7,11] } # [6,8] [0,0] [2,6] [7,10] [2,12] [8,9] [1,7] [4,9] [1,5] [3,12] [1,4] } #
[3,5] [0,9] [4,7] [6,10] [3,11] [0,10] [2,10] [7,8] [1,12] [2,2] [0,5] } # [4,8] [3,9] [5,6] [9,11] [2,4] [0,6] [0,7] [0,3] [9,10] [7,7] [0,8] } #
[4,6] [3,4] [3,6] [1,6] [6,7] [0,11] [6,6] [5,8] [10,11] [7,12] [0,4] } # [3,10] [8,11] [4,12] [2,7] [7,9] [8,12] [8,10] [2,3] [1,9] [4,10] [5,9] } #
[6,11] [1,11] [2,8] [6,12] [2,9] [1,3] [9,12] [5,11] [5,10] [12,12] [0,2] }
Figure 1: A properly formatted DOmino Configuration (doc) encoding
The assignment is made up of two parts: scanning the text of the input file and parsing the information contained in the input file.
1.2 Scanning
Construct a combined grammar in a .g4 file that ANTLR can use to scan a supplied Domino Configuration encoding. The logic in this file should be robust enough to identify tokens in the encoding and accurately process any correctly formatted encoding. The rules in your .g4 file will be augmented with actions that display information about the input file. An example of that output is specified in Section 2.
The purpose of the scanner is to extract tokens from the input and pass those along to the parser. For the Domino Configuration encoding, the types of tokens that you will need to consider are given in Table 1.
1
1.2.1 Invalid Encodings
Type Section Beginning Section Ending Section Title Domino Symbol Numerical Symbol Row Ending List Beginning List Ending White Space (to be ignored)
Form
<<
>>
<Trains and <Hands
One or more Numerical Symbols 0,1,2,3,4,5,6,7,8,or9
#
{
}
spaces, tabs, newlines
Table 1: Tokens to Consider
For invalid Domino Configuration encodings, the output Notification: Problem on Line L should dis- play. L would be the line of input where the unknown symbol was read. Your scanner should stop scanning the file after an unrecognized token is found.
1.3 Parsing
Construct a combined grammar in a .g4 file that ANTLR can use to parse a supplied Domino Configuration encoding. In addition to the rules for scanning, there are several parsing rules:
• There must be more than one (1) player (hand) in a game
• There must be more than one (1) player (train) in a game
The semantics of a properly formatted Domino Configuration encoding are:
- There must be between 3 and 10 (inclusive) hands in a game
- The number of played dominoes (dominoes in trains) must not exceed 20% of all dominoes in a game
- Extra Credit (10 points or Honors contract): No train may be more than one (1) domino longer than any other train in the game
2 Output 2.1 Scanner
Your .g4 file should produce output for both correctly formatted files and incorrectly formatted files. For the correctly formatted file in Figure 1, the output would have the form of the output presented in Figure 2
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Portion: Trains Begin Section Begin List Begin Domino Half: 6
Half: 9
Conclude Domino Begin Domino Half: 9
Half: 9
Conclude Domino Conclude List Conclude Row Begin List
Begin Domino Half: 0
…
Begin Domino Half: 8
Half: 8
Conclude Domino Conclude List Conclude Section Portion: Hands Begin Section Begin List
Begin Domino Half: 3
Half: 7
Conclude Domino Begin Domino Half: 1
…
Begin Domino Half: 0
Half: 2
Conclude Domino Conclude List Conclude Section Conclude File
Figure 2: Truncated Output of Scanner for File in Figure 1
For a correctly formatted file in Part 2, the output would be: d dominoes have been played where d is the number of dominoes that have been played in the Trains . For the file in Figure 1, the output would be
14 dominoes have been played.
2.2 Invalid Syntax & Semantics in Parsing
For invalid encodings in Part 2, a message describing the error should be displayed. For a syntax error (violation of the syntax rules), the output
Notification: Problem on Line L should be displayed, where L is the line number where the unrec- ognized token was found. For that error, the parser should stop processing the file. For a semantic rule violation, the output
Notification: Semantic Problem Rshouldbedisplayed,whereRisthenumberoftherule(fromList1.3) that was violated, but parsing should continue.
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Syntax errors in Part 2 should be reported in the syntaxError method of csce322Homework01Part02Error.java.
3 Naming Conventions
The ANTLR file for the first part of the assignment should be named csce322Homework01Part01.g4. The ANTLR file for the second part of the assignment should be named csce322Homework01Part02.g4. Both grammars should contain a start rule named dominoes. The Java file for the second part of the assignment should be named csce322Homework01Part02Error.java.
4 webgrader
The webgrader is available for this assignment. You can test your submitted files before the deadline by submitting them on webhandin and going to http://cse.unl.edu/ ̃cse322/grade, choosing the correct assignment and entering your cse.unl.edu credentials
The script should take approximately 2 minutes to run and produce a PDF.
4.1 The Use of diff
Because Part 1 of this assignment only depends on the symbols in the file, the order in which they are displayed should not be submission dependent. Therefore, diff will be used to compare the output of a particular submission against the output of the solution implementation. For Part 2, order and repeated output lines will not influence diff.
- 5 Point Allocation
- 6 External Resources
ANTLR
Getting Started with ANTLR v4 ANTLR 4 Documentation
Overview (ANTLR 4 Runtime 4.7 API)
7 Commands of Interest
alias antlr4=’java -jar /path/to/antlr-4.7.1-complete.jar’ alias grun=’java org.antlr.v4.gui.TestRig ‘
export CLASSPATH=”/path/to/antlr -4.7.1-complete.jar:$CLASSPATH” antlr4 /path/to/csce322Homework01Part0#.g4
javac -d /path/for/.classfiles /path/to/csce322Homework01Part0#*.java
java /path/of/.classfiles csce322Homework01Part02Driver /path/to/inputfile grun csce322Homework01Part0# dominoes -gui
grun csce322Homework01Part0# dominoes -gui /path/to/inputfile
grun csce322Homework01Part0# dominoes
grun csce322Homework01Part0# dominoes /path/to/inputfile
|
Component |
Points |
|
Part 1 Part 2 |
35 65 |
|
Total |
100 |
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