From a99b6b647fa258d2ec6b59349ea0a51a48f36c6b Mon Sep 17 00:00:00 2001
From: Danila Fedorin <danila.fedorin@gmail.com>
Date: Sat, 29 Jul 2017 21:02:41 -0700
Subject: [PATCH] Implement the components of a new tree builder.

---
 src/org/nwapw/abacus/parsing/Parser.java      | 10 ++++++++
 src/org/nwapw/abacus/parsing/Tokenizer.java   |  9 ++++++++
 src/org/nwapw/abacus/parsing/TreeBuilder.java | 23 +++++++++++++++++++
 3 files changed, 42 insertions(+)
 create mode 100644 src/org/nwapw/abacus/parsing/Parser.java
 create mode 100644 src/org/nwapw/abacus/parsing/Tokenizer.java
 create mode 100644 src/org/nwapw/abacus/parsing/TreeBuilder.java

diff --git a/src/org/nwapw/abacus/parsing/Parser.java b/src/org/nwapw/abacus/parsing/Parser.java
new file mode 100644
index 0000000..0103a7d
--- /dev/null
+++ b/src/org/nwapw/abacus/parsing/Parser.java
@@ -0,0 +1,10 @@
+package org.nwapw.abacus.parsing;
+
+import org.nwapw.abacus.tree.TreeNode;
+
+import java.util.List;
+
+public interface Parser<T> {
+
+    public TreeNode constructTree(List<T> tokens);
+}
diff --git a/src/org/nwapw/abacus/parsing/Tokenizer.java b/src/org/nwapw/abacus/parsing/Tokenizer.java
new file mode 100644
index 0000000..4baef10
--- /dev/null
+++ b/src/org/nwapw/abacus/parsing/Tokenizer.java
@@ -0,0 +1,9 @@
+package org.nwapw.abacus.parsing;
+
+import java.util.List;
+
+public interface Tokenizer<T> {
+
+    public List<T> tokenizeString(String string);
+
+}
diff --git a/src/org/nwapw/abacus/parsing/TreeBuilder.java b/src/org/nwapw/abacus/parsing/TreeBuilder.java
new file mode 100644
index 0000000..57de6ed
--- /dev/null
+++ b/src/org/nwapw/abacus/parsing/TreeBuilder.java
@@ -0,0 +1,23 @@
+package org.nwapw.abacus.parsing;
+
+import org.nwapw.abacus.tree.TreeNode;
+
+import java.util.List;
+
+public class TreeBuilder<T> {
+
+    private Tokenizer<T> tokenizer;
+    private Parser<T> parser;
+
+    public TreeBuilder(Tokenizer<T> tokenizer, Parser<T> parser){
+        this.tokenizer = tokenizer;
+        this.parser = parser;
+    }
+
+    public TreeNode fromString(String input){
+        List<T> tokens = tokenizer.tokenizeString(input);
+        if(tokens == null) return null;
+        return parser.constructTree(tokens);
+    }
+
+}