Rework parsing structure

src/parser/grammars/Tokens.kt

@@ -0,0 +1,32 @@
+package parser.grammars
+
+import com.github.h0tk3y.betterParse.combinators.use
+import com.github.h0tk3y.betterParse.grammar.Grammar
+import com.github.h0tk3y.betterParse.lexer.Token
+import com.github.h0tk3y.betterParse.lexer.literalToken
+import com.github.h0tk3y.betterParse.lexer.regexToken
+import com.github.h0tk3y.betterParse.lexer.token
+
+abstract class Tokens : Grammar<Any>() {
+    // Prolog tokens
+    protected val nameToken: Token by regexToken("[a-z][a-zA-Z0-9_]*")
+    protected val variableToken: Token by regexToken("[A-Z][a-zA-Z0-9_]*")
+
+    // Arithmetic tokens
+    protected val floatToken: Token by regexToken("-?[1-9][0-9]*\\.[0-9]+")
+    protected val integerToken: Token by regexToken("-?([1-9][0-9]*|0)")
+
+    // Special tokens
+    protected val neck by literalToken(":-")
+    protected val comma: Token by literalToken(",")
+    protected val leftParenthesis: Token by literalToken("(")
+    protected val rightParenthesis: Token by literalToken(")")
+    protected val dot by literalToken(".")
+
+    // Ignored tokens
+    protected val whitespace: Token by regexToken("\\s+", ignore = true)
+    protected val singleLineComment: Token by regexToken("%[^\\n]*", ignore = true)
+    protected val multiLineComment: Token by regexToken("/\\*.*?\\*/", ignore = true)
+
+    protected val dummy by token { _, _ -> -1 } use { throw IllegalStateException("This parser should not be used") }
+}