private String eatArgValue() {
		Token t = tokens.next();
		String argValue = null;
		if (t.getKind() == TokenKind.IDENTIFIER) {
			argValue = t.data;
		}
		else if (t.getKind() == TokenKind.LITERAL_STRING) {
			String quotesUsed = t.data.substring(0, 1);
			argValue = t.data.substring(1, t.data.length() - 1).replace(quotesUsed + quotesUsed, quotesUsed);
		}
		else {
			tokens.raiseException(t.startpos, JobDSLMessage.EXPECTED_ARGUMENT_VALUE, t.data);
		}
		return argValue;
	}
Parse a job flow definition into an abstract syntax tree (AST).

@param jobSpecification the textual job specification
@return the AST for the parsed job
@throws JobSpecificationException if any problems occur during parsing
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/job/dsl/JobParser.java