Method matchId

chapter17/src/main/java/com/seaofnodes/simple/Parser.java:1193–1200

()

    }

    private String matchId() {
        int old = pos();
        String id = _lexer.matchId();
        if( id==null ) return null;
        if( !KEYWORDS.contains(id) ) return id;
        pos(old);
        return null;
    }

    // Require an exact match
    private Parser require(String syntax) { require(null, syntax); return this; }