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package bjc.dicelang.expr;
import java.util.Scanner;
import bjc.utils.data.ITree;
import bjc.utils.funcdata.IList;
import bjc.utils.parserutils.TreeConstructor;
public class ExprREPL {
/*
* @TODO 10/08/17 Ben Culkin :MainSeperation
*
* This main method should be moved to its own class.
*/
/**
* Main method.
*
* @param args
* Unused CLI args.
*/
public static void main(final String[] args) {
/* Create our objects. */
final Tokens toks = new Tokens();
final Lexer lex = new Lexer();
/* Prepare our input source. */
final Scanner scan = new Scanner(System.in);
/* Read initial command. */
System.out.print("Enter a math expression (blank line to quit): ");
String ln = scan.nextLine().trim();
/* Enter REPL loop. */
while (!ln.equals("")) {
/* Print raw command. */
System.out.println("Raw command: " + ln);
System.out.println();
/* Lex command to infix tokens. */
final Token[] infixTokens = lex.lexString(ln, toks);
System.out.println("Lexed tokens: ");
for (final Token tok : infixTokens) {
System.out.println("\t" + tok);
}
/* Print out infix expression. */
System.out.print("Lexed expression: ");
for (final Token tok : infixTokens) {
System.out.print(tok.toExpr() + " ");
}
/* Space stages. */
System.out.println();
System.out.println();
/* Shunt infix tokens to postfix tokens. */
final IList<Token> postfixTokens = Shunter.shuntTokens(infixTokens);
System.out.println("Lexed tokens: ");
for (final Token tok : postfixTokens) {
System.out.println("\t" + tok);
}
/* Print out postfix tokens. */
System.out.print("Shunted expression: ");
for (final Token tok : postfixTokens) {
System.out.print(tok.toExpr() + " ");
}
/* Space stages. */
System.out.println();
System.out.println();
/* Construct a tree from the list of postfixed tokens. */
final ITree<Token> ast = TreeConstructor.constructTree(postfixTokens, tok -> tok.typ.isOperator);
/* Print the tree, then the canonical expression for it. */
System.out.println("Parsed tree");
System.out.println(ast.toString());
System.out.println("\nCanonical expr: " + Parser.toCanonicalExpr(ast));
/* Space stages. */
System.out.println();
System.out.println();
/* Prompt for a new expression. */
System.out.print("Enter a math expression (blank line to quit): ");
/* Read it. */
ln = scan.nextLine().trim();
}
/* Cleanup after ourselves. */
scan.close();
}
}
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