diff options
Diffstat (limited to 'JPratt/src/main/java/bjc/pratt/tokens/StringTokenStream.java')
| -rw-r--r-- | JPratt/src/main/java/bjc/pratt/tokens/StringTokenStream.java | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/JPratt/src/main/java/bjc/pratt/tokens/StringTokenStream.java b/JPratt/src/main/java/bjc/pratt/tokens/StringTokenStream.java new file mode 100644 index 0000000..7f8215a --- /dev/null +++ b/JPratt/src/main/java/bjc/pratt/tokens/StringTokenStream.java @@ -0,0 +1,56 @@ +package bjc.pratt.tokens; + +import bjc.pratt.Token; +import bjc.pratt.TokenStream; + +import java.util.Iterator; + +import static bjc.pratt.tokens.StringToken.litToken; + +/** + * Simple implementation of token stream for strings. + * + * The terminal token here is represented by a token with type and value + * '(end)'. + * + * @author EVE + * + */ +public class StringTokenStream extends TokenStream<String, String> { + private Iterator<Token<String, String>> iter; + + private Token<String, String> curr; + + /** + * Create a new token stream from a iterator. + * + * @param itr + * The iterator to use. + * + */ + public StringTokenStream(Iterator<Token<String, String>> itr) { + iter = itr; + + } + + @Override + public Token<String, String> current() { + return curr; + } + + @Override + public Token<String, String> next() { + if (iter.hasNext()) { + curr = iter.next(); + } else { + curr = litToken("(end)"); + } + + return curr; + } + + @Override + public boolean hasNext() { + return iter.hasNext(); + } +} |
