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source: addons/HeuristicLab.PushGP/HeuristicLab.Problem.ProgramSynthesis.BenchmarkSuite/CsvParser.cs @ 17460

Last change on this file since 17460 was 15017, checked in by pkimmesw, 8 years ago

#2665 Fixed Benchmark Problem Definition, Converted LoopExpressions to stateless expressions, Added several unit test to ensure funcionality, Fixed UI bugs

File size: 3.1 KB
Line 
1/*
2 * License: CPOL
3 * Source: https://www.codeproject.com/Tips/823670/Csharp-Light-and-Fast-CSV-Parser
4 * Author: Yuriy Magurdumov
5 */
6
7using System;
8using System.Collections.Generic;
9using System.Text;
10
11namespace HeuristicLab.BenchmarkSuite {
12  using System.IO;
13
14  public static class CsvParser {
15    private static Tuple<T, IEnumerable<T>> HeadAndTail<T>(this IEnumerable<T> source) {
16      if (source == null)
17        throw new ArgumentNullException("source");
18      var en = source.GetEnumerator();
19      en.MoveNext();
20      return Tuple.Create(en.Current, EnumerateTail(en));
21    }
22
23    private static IEnumerable<T> EnumerateTail<T>(IEnumerator<T> en) {
24      while (en.MoveNext()) yield return en.Current;
25    }
26
27    public static IEnumerable<IList<string>> Parse(string content, char delimiter, char qualifier) {
28      using (var reader = new StringReader(content))
29        return Parse(reader, delimiter, qualifier);
30    }
31
32    public static Tuple<IList<string>, IEnumerable<IList<string>>> ParseHeadAndTail(TextReader reader, char delimiter, char qualifier) {
33      return HeadAndTail(Parse(reader, delimiter, qualifier));
34    }
35
36    public static IEnumerable<IList<string>> Parse(TextReader reader, char delimiter, char qualifier) {
37      var inQuote = false;
38      var record = new List<string>();
39      var sb = new StringBuilder();
40
41      while (reader.Peek() != -1) {
42        var readChar = (char)reader.Read();
43
44        if (readChar == '\n' || (readChar == '\r' && (char)reader.Peek() == '\n')) {
45          // If it's a \r\n combo consume the \n part and throw it away.
46          if (readChar == '\r')
47            reader.Read();
48
49          if (inQuote) {
50            if (readChar == '\r')
51              sb.Append('\r');
52            sb.Append('\n');
53          } else {
54            if (record.Count > 0 || sb.Length > 0) {
55              record.Add(sb.ToString());
56              sb.Clear();
57            }
58
59            if (record.Count > 0)
60              yield return record;
61
62            record = new List<string>(record.Count);
63          }
64        } else if (sb.Length == 0 && !inQuote) {
65          if (readChar == qualifier)
66            inQuote = true;
67          else if (readChar == delimiter) {
68            record.Add(sb.ToString());
69            sb.Clear();
70          //} else if (char.IsWhiteSpace(readChar)) { // Ignore leading whitespace
71          } else
72            sb.Append(readChar);
73        } else if (readChar == delimiter) {
74          if (inQuote)
75            sb.Append(delimiter);
76          else {
77            record.Add(sb.ToString());
78            sb.Clear();
79          }
80        } else if (readChar == qualifier) {
81          if (inQuote) {
82            if ((char)reader.Peek() == qualifier) {
83              reader.Read();
84              sb.Append(qualifier);
85            } else
86              inQuote = false;
87          } else
88            sb.Append(readChar);
89        } else
90          sb.Append(readChar);
91      }
92
93      if (record.Count > 0 || sb.Length > 0)
94        record.Add(sb.ToString());
95
96      if (record.Count > 0)
97        yield return record;
98    }
99  }
100}
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