kiloz

commit 47ff0ed3be44c1ebe20aad21033e3e372d1c64ec
parent d16a87f06db376f22748512a41d2d7b088545765
Author: Martin Ashby <martin@ashbysoft.com>
Date:   Sat, 13 Jan 2024 08:45:01 +0000

Step 65

Diffstat:
M
src/main.zig
 | 
65
+++++++++++++++++++++++++++++++++++++++++++++++++++++++----------

1 file changed, 55 insertions(+), 10 deletions(-)
diff --git a/src/main.zig b/src/main.zig
@@ -14,7 +14,12 @@ pub fn main() !void {
     defer clearScreen();
 
     try initEditor(&es);
-
+    const args = try std.process.argsAlloc(es.a);
+    defer std.process.argsFree(es.a, args);
+    if (args.len > 1) {
+        try editorOpen(&es, args[1]);
+    }
+    
     while (true) {
         try editorRefreshScreen(&es);
 
@@ -35,15 +40,22 @@ const EditorState = struct {
     screencols: u16 = 0,
     cx: u16 = 10,
     cy: u16 = 10,
+    erow: []ERow = &[_]ERow{},
 
     fn init(a: std.mem.Allocator) EditorState {
         return .{ .a = a };
     }
     fn deinit(self: *EditorState) void {
         self.screen_buf.deinit(self.a);
+        for (self.erow) |erow| {
+            self.a.free(erow);
+        }
+        self.a.free(self.erow);
     }
 };
 
+const ERow = []u8;
+
 //// Terminal handling
 
 // Returns the original termios setting for restoring terminal function at exit.
@@ -177,6 +189,34 @@ fn getWindowSize() !Size {
     }
 }
 
+//// Row operations
+
+fn editorAppendRow(es: *EditorState, line: []u8) !void {
+    const numrows = es.erow.len;
+    es.erow = try es.a.realloc(es.erow, numrows + 1);
+    es.erow[numrows] = line;
+}
+
+//// File i/o
+
+fn editorOpen(es: *EditorState, filename: []const u8) !void {
+    const f = try std.fs.cwd().openFile(filename, .{});
+    defer f.close();
+    var br = std.io.bufferedReader(f.reader());
+    var rdr = br.reader();
+    var al = std.ArrayList(u8).init(es.a);
+    defer al.deinit();
+    lp: while (true) {
+        rdr.streamUntilDelimiter(al.writer(), '\n', null) catch |e| switch (e) {
+            error.EndOfStream => break :lp,
+            else => return e,
+        };
+        const line = try al.toOwnedSlice();
+        errdefer es.a.free(line);
+        try editorAppendRow(es, line);
+    }
+}
+
 //// Output
 
 fn clearScreen() void {
@@ -206,20 +246,25 @@ fn editorDrawRows(es: *const EditorState, wtr: anytype) !void {
 
         var lw = limitedWriter(wtr, es.screencols); // Never write more than we have columns
         const wtr2 = lw.writer();
-        if (y == es.screenrows / 3) {
-            const welcome_msg = try std.fmt.allocPrint(es.a, "Kilo editor -- version {s}", .{version}); // TODO don't allocate every time...
-            defer es.a.free(welcome_msg);
-            const padding = (es.screencols - welcome_msg.len) / 2;
-            for (0..padding) |y2| {
-                try wtr2.writeByte(if (y2 == 0) '~' else ' ');
+        if (y >= es.erow.len) {
+            if (es.erow.len == 0 and y == es.screenrows / 3) {
+                const welcome_msg = try std.fmt.allocPrint(es.a, "Kilo editor -- version {s}", .{version}); // TODO don't allocate every time...
+                defer es.a.free(welcome_msg);
+                const padding = (es.screencols - welcome_msg.len) / 2;
+                for (0..padding) |y2| {
+                    try wtr2.writeByte(if (y2 == 0) '~' else ' ');
+                }
+                try wtr2.writeAll(welcome_msg);
+            } else {
+                try wtr2.writeAll("~");
             }
-            try wtr2.writeAll(welcome_msg);
         } else {
-            try wtr2.writeAll("~");
+            try wtr2.writeAll(es.erow[y]);
         }
 
-        if (y < es.screenrows-1)
+        if (y < es.screenrows-1) {
             try wtr.writeAll("\r\n");
+        }
     }
 }