Add functionality for skipping words left and right

2 files changed, 50 insertions, 0 deletions

diff --git a/src/Buffer.zig b/src/Buffer.zig
index bb6d3ce..26f9a93 100644
--- a/src/Buffer.zig
+++ b/src/Buffer.zig
@@ -110,6 +110,26 @@ pub fn backwardParagraph(self: *Buffer) void {
     self.cx = 0;
 }
 
+pub fn backwardWord(self: *Buffer) void {
+    if (self.cx == 0) {
+        return self.backwardChar();
+    }
+
+    const chars = self.rows.items[self.cy].data.items;
+    // First we skip non-word
+    while (self.cx > 0) : (self.cx -= 1) {
+        if (std.ascii.isAlphanumeric(chars[self.cx - 1])) {
+            break;
+        }
+    }
+    // Then we skip word
+    while (self.cx > 0) : (self.cx -= 1) {
+        if (!std.ascii.isAlphanumeric(chars[self.cx - 1])) {
+            break;
+        }
+    }
+}
+
 pub fn cleanWhiteSpace(self: *Buffer) !void {
     for (self.rows.items) |*row| {
         try row.cleanWhiteSpace(self);
@@ -304,6 +324,30 @@ pub fn forwardParagraph(self: *Buffer) void {
     self.cx = 0;
 }
 
+pub fn forwardWord(self: *Buffer) void {
+    if (self.cy == self.rows.items.len) {
+        return;
+    }
+
+    const chars = self.rows.items[self.cy].data.items;
+    if (self.cx == chars.len) {
+        return self.forwardChar();
+    }
+
+    // First we skip non-word
+    while (self.cx < chars.len) : (self.cx += 1) {
+        if (std.ascii.isAlphanumeric(chars[self.cx])) {
+            break;
+        }
+    }
+    // Then we skip word
+    while (self.cx < chars.len) : (self.cx += 1) {
+        if (!std.ascii.isAlphanumeric(chars[self.cx])) {
+            break;
+        }
+    }
+}
+
 // TODO: Make use of the callback feature to go to the final line while typing in.
 pub fn goToLine(self: *Buffer, editor: *Editor) !void {
     if (try editor.prompt(self.allocator, "Goto line")) |line_str| {
diff --git a/src/KeyMap.zig b/src/KeyMap.zig
index 90dcd01..8dca48d 100644
--- a/src/KeyMap.zig
+++ b/src/KeyMap.zig
@@ -113,7 +113,11 @@ pub fn defaultMap(allocator: Allocator) !KeyMap {
 
     // M-<*>
     try map.bind(&.{Key.meta(Key.down)}, Buffer.forwardParagraph);
+    try map.bind(&.{Key.meta(Key.left)}, Buffer.backwardWord);
+    try map.bind(&.{Key.meta(Key.right)}, Buffer.forwardWord);
     try map.bind(&.{Key.meta(Key.up)}, Buffer.backwardParagraph);
+    try map.bind(&.{Key.meta('b')}, Buffer.backwardWord);
+    try map.bind(&.{Key.meta('f')}, Buffer.forwardWord);
     // M-g is taken
     try map.bind(&.{Key.meta('n')}, Buffer.forwardParagraph);
     // M-O is taken
@@ -122,6 +126,8 @@ pub fn defaultMap(allocator: Allocator) !KeyMap {
 
     // C-<*>
     try map.bind(&.{Key.ctrl(Key.down)}, Buffer.forwardParagraph);
+    try map.bind(&.{Key.ctrl(Key.left)}, Buffer.backwardWord);
+    try map.bind(&.{Key.ctrl(Key.right)}, Buffer.forwardWord);
     try map.bind(&.{Key.ctrl(Key.up)}, Buffer.backwardParagraph);
     try map.bind(&.{Key.ctrl('a')}, Buffer.moveBeginningOfLine);
     try map.bind(&.{Key.ctrl('b')}, Buffer.backwardChar);