I'm having an issue with my RegEx's match returning a false Success. In this case, I tested a blank space against this RegEx pattern:
And whenever I call:
The conditional statement returns a True value. I've checked my pattern here and the pattern only matches dots and hyphens, not the whitespace afterwards so I'm not sure why it's not preforming the same in my code. Here is the full code incase y'all want a peek:
Code:
(\.|-)*Code:
If match.Success ThenCode:
Option Strict On
Option Explicit On
Module Lexer
Private classes As List(Of List(Of String))
Private Function LoadClasses() As List(Of List(Of String))
Dim ticks As List(Of String) = New List(Of String)
ticks.AddRange({"tick", "(\.|-)*"}) 'Match any "." or "-", 0 or more times
Dim whitespace As List(Of String) = New List(Of String)
whitespace.AddRange({"whitespace", "\s"}) 'Match any space, tab, or new line
Dim comments As List(Of String) = New List(Of String)
comments.AddRange({"comment", "#.*"}) 'Match any "#" and all leading characters until the new line
Return {ticks, whitespace, comments}.ToList
End Function
Public Function Scan(ByVal source As String, ByRef tokens() As String, ByRef values() As String) As String()
'Setup our token classes(if applicable)
If IsNothing(classes) Then
classes = LoadClasses()
End If
'Our ByRefs we'll be returning
Dim tokenCollection As List(Of String) = New List(Of String)
Dim valueCollection As List(Of String) = New List(Of String)
'The exceptions we'll be returning(hopefully none)
Dim exceptions As List(Of String) = New List(Of String)
'Loop through each line
For x As Integer = 0 To source.Split({Environment.NewLine}, StringSplitOptions.None).Count - 1
Dim line As String = source.Split({Environment.NewLine}, StringSplitOptions.None)(x)
'Loop through each word in that line
For y As Integer = 0 To line.Split().Count - 1
Dim word As String = line.Split()(y)
Dim token As String = String.Empty
'Loop through each token class
For t As Integer = 0 To classes.Count - 1
Dim tokenClass As List(Of String) = classes.Item(t)
'Loop through each RegEx pattern in our class
For r As Integer = 1 To tokenClass.Count - 1
'Use RegEx to check for a match
Dim regex As System.Text.RegularExpressions.Regex = New System.Text.RegularExpressions.Regex(tokenClass.Item(r))
Dim match As System.Text.RegularExpressions.Match = regex.Match(word)
If match.Success Then
'If there is a match the set the token variable and leave the RegEx loop
token = tokenClass.Item(0)
Exit For
End If
Next 'End of RegEx
'Leave the token class loop if there is already a match
If Not String.IsNullOrWhiteSpace(token) Then
Exit For
End If
Next 'End of token class
If String.IsNullOrWhiteSpace(token) Then
exceptions.Add(String.Format("{0} is an unrecognizable character", word))
Else
'Otherwise add it to the collection if it's not a comment
If token <> "comment" Then
tokenCollection.Add(token)
valueCollection.Add(word)
Else
'Add the newline token if there is one
If line.Substring(line.Length - 1) = Environment.NewLine Then
tokenCollection.Add("whitespace")
valueCollection.Add(Environment.NewLine)
End If
End If
End If
Next 'End of the word
Next 'End of line
'Don't return any tokens/values if there are exceptions
If exceptions.Count > 0 Then
tokenCollection = Nothing
valueCollection = Nothing
Else
tokens = tokenCollection.ToArray
values = valueCollection.ToArray
End If
Return exceptions.ToArray
End Function
End Module
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