Initial commit

2026-03-11 23:22:41 +09:00 · 2016-03-10 21:06:06 -05:00
commit 24ce1d6b42
8 changed files with 519 additions and 0 deletions
--- a/src/buffer.d
+++ b/src/buffer.d
@@ -0,0 +1,167 @@
+import std.math;
+import std.stdio;
+import std.utf;
+import std.string;
+import std.conv: to;
+import std.algorithm;
+
+class Buffer {
+    private string value = null;
+    private Buffer left;
+    private Buffer right;
+
+    string name = "";
+    string savedText;
+
+    ulong length;
+
+    int splitLength = 1000;
+    int joinLength = 500;
+    double rebalanceRatio = 1.2;
+
+    this() { }
+
+    this(string str, string name = "") {
+        this.value = str;
+        this.length = str.length;
+        this.name = name;
+        this.savedText = str;
+
+        left = new Buffer();
+        right = new Buffer();
+        left.value = "";
+        right.value = "";
+
+        adjust();
+    }
+
+    void save(string filename = null) {
+        if (filename is null) {
+            filename = name;
+        }
+        if (filename != "") {
+            string bufSrc = this.toString();
+            File f = File(filename, "w");
+            f.write(bufSrc);
+            f.close();
+            savedText = bufSrc;
+        }
+    }
+
+    @property string[] lines() {
+        string str = this.toString();
+        if (str == "") {
+            return [""];
+        } else {
+            return str.split("\n");
+        }
+    }
+
+    void adjust() {
+        if (value !is null) {
+            if (length > splitLength) {
+                auto divide = cast(int) floor(length / 2.0);
+                left = new Buffer(value[0 .. divide]);
+                right = new Buffer(value[divide .. $]);
+            }
+        } else {
+            if (length < joinLength) {
+                value = left.toString() ~ right.toString();
+            }
+        }
+    }
+
+    override
+    string toString() {
+        if (value !is null) {
+            return value;
+        } else {
+            return left.toString ~ right.toString();
+        }
+    }
+
+    void remove(ulong start, ulong end) {
+        if (value !is null) {
+            value = value[0 .. start] ~ value[end .. $];
+            length = value.length;
+        } else {
+            auto leftStart = min(start, left.length);
+            auto leftEnd = min(end, left.length);
+            auto rightStart = max(0, min(start - left.length, right.length));
+            auto rightEnd = max(0, min(end - left.length, right.length));
+            if (leftStart < left.length) {
+                left.remove(leftStart, leftEnd);
+            }
+            if (rightEnd > 0) {
+                right.remove(rightStart, rightEnd);
+            }
+            length = left.length + right.length;
+        }
+
+        adjust();
+    }
+
+    void insert(ulong position, string value) {
+        if (this.value !is null) {
+            this.value = this.value[0 .. position] ~ value ~ this.value[position .. $];
+            length = this.value.length;
+        } else {
+            if (position < left.length) {
+                left.insert(position, value);
+                length = left.length + right.length;
+            } else {
+                right.insert(position - left.length, value);
+            }
+        }
+
+        adjust();
+    }
+
+    void rebuild() {
+        if (value is null) {
+            value = left.toString() ~ right.toString();
+            adjust();
+        }
+    }
+
+    void rebalance() {
+        if (value is null) {
+            if (left.length / right.length > rebalanceRatio ||
+                right.length / left.length > rebalanceRatio) {
+                rebuild();
+            } else {
+                left.rebalance();
+                right.rebalance();
+            }
+        }
+    }
+
+    string substring(ulong start, ulong end = length) {
+        if (value !is null) {
+            return value[start .. end];
+        } else {
+            auto leftStart = min(start, left.length);
+            auto leftEnd = min(end, left.length);
+            auto rightStart = max(0, min(start - left.length, right.length));
+            auto rightEnd = max(0, min(end - left.length, right.length));
+
+            if (leftStart != leftEnd) {
+                if (rightStart != rightEnd) {
+                    return left.substring(leftStart, leftEnd) ~ right.substring(rightStart, rightEnd);
+                } else {
+                    return left.substring(leftStart, leftEnd);
+                }
+            } else {
+                if (rightStart != rightEnd) {
+                    return right.substring(rightStart, rightEnd);
+                } else {
+                    return "";
+                }
+            }
+        }
+    }
+
+    char charAt(ulong pos) {
+        return to!char(substring(pos, pos + 1));
+    }
+}