Separate general I/O from parsing.

1 files changed, 80 insertions, 0 deletions

diff --git a/BJC-Utils2/src/main/java/bjc/utils/ioutils/RuleBasedReaderPragmas.java b/BJC-Utils2/src/main/java/bjc/utils/ioutils/RuleBasedReaderPragmas.java
new file mode 100644
index 0000000..f19eb2c
--- /dev/null
+++ b/BJC-Utils2/src/main/java/bjc/utils/ioutils/RuleBasedReaderPragmas.java
@@ -0,0 +1,80 @@
+package bjc.utils.ioutils;
+
+import bjc.utils.exceptions.PragmaFormatException;
+import bjc.utils.funcdata.FunctionalStringTokenizer;
+import bjc.utils.funcutils.ListUtils;
+
+import java.util.function.BiConsumer;
+
+/**
+ * Contains factory methods for common pragma types
+ *
+ * @author ben
+ *
+ */
+public class RuleBasedReaderPragmas {
+
+	/**
+	 * Creates a pragma that takes a single integer argument
+	 *
+	 * @param <StateType>
+	 *                The type of state that goes along with this pragma
+	 * @param name
+	 *                The name of this pragma, for error message purpose
+	 * @param consumer
+	 *                The function to invoke with the parsed integer
+	 * @return A pragma that functions as described above.
+	 */
+	public static <StateType> BiConsumer<FunctionalStringTokenizer, StateType> buildInteger(String name,
+			BiConsumer<Integer, StateType> consumer) {
+		return (tokenizer, state) -> {
+			// Check our input is correct
+			if(!tokenizer.hasMoreTokens())
+				throw new PragmaFormatException("Pragma " + name + " requires one integer argument");
+
+			// Read the argument
+			String token = tokenizer.nextToken();
+
+			try {
+				// Run the pragma
+				consumer.accept(Integer.parseInt(token), state);
+			} catch(NumberFormatException nfex) {
+				// Tell the user their argument isn't correct
+				PragmaFormatException pfex = new PragmaFormatException(
+						"Argument " + token + " to " + name + " pragma isn't a valid integer. "
+								+ "This pragma requires a integer argument");
+
+				pfex.initCause(nfex);
+
+				throw pfex;
+			}
+		};
+	}
+
+	/**
+	 * Creates a pragma that takes any number of arguments and collapses
+	 * them all into a single string
+	 *
+	 * @param <StateType>
+	 *                The type of state that goes along with this pragma
+	 * @param name
+	 *                The name of this pragma, for error message purpose
+	 * @param consumer
+	 *                The function to invoke with the parsed string
+	 * @return A pragma that functions as described above.
+	 */
+	public static <StateType> BiConsumer<FunctionalStringTokenizer, StateType> buildStringCollapser(String name,
+			BiConsumer<String, StateType> consumer) {
+		return (tokenizer, state) -> {
+			// Check our input
+			if(!tokenizer.hasMoreTokens()) throw new PragmaFormatException(
+					"Pragma " + name + " requires one or more string arguments");
+
+			// Build our argument
+			String collapsed = ListUtils.collapseTokens(tokenizer.toList());
+
+			// Run the pragma
+			consumer.accept(collapsed, state);
+		};
+	}
+}