add --lang and --theme options

src/file_type.zig

@@ -12,6 +12,13 @@ injections: ?[:0]const u8,
 first_line_matches: ?FirstLineMatch = null,
 comment: []const u8,
 
+pub fn get_by_name(name: []const u8) ?*const FileType {
+    for (file_types) |*file_type|
+        if (std.mem.eql(u8, file_type.name, name))
+            return file_type;
+    return null;
+}
+
 pub fn guess(file_path: ?[]const u8, content: []const u8) ?*const FileType {
     if (guess_first_line(content)) |ft| return ft;
     for (file_types) |*file_type|

src/main.zig

@@ -7,10 +7,14 @@ const term = @import("ansi-term.zig");
 
 const StyleCache = std.AutoHashMap(u32, ?Theme.Token);
 var style_cache: StyleCache = undefined;
+var lang_override: ?[]const u8 = null;
 
 pub fn main() !void {
     const params = comptime clap.parseParamsComptime(
         \\-h, --help               Display this help and exit.
+        \\-l, --lang <str>         Override the language.
+        \\-t, --theme <str>        Select theme to use.
+        \\--list-themes            Show available themes.
         \\<str>...                 File to open.
         \\
     );
@@ -34,7 +38,17 @@ pub fn main() !void {
     if (res.args.help != 0)
         return clap.help(std.io.getStdErr().writer(), clap.Help, &params, .{});
 
-    const theme = get_theme_by_name("default") orelse unreachable;
+    if (res.args.@"list-themes" != 0)
+        return list_themes(std.io.getStdOut().writer());
+
+    const theme_name = if (res.args.theme) |theme| theme else "default";
+
+    const theme = get_theme_by_name(theme_name) orelse {
+        try std.io.getStdErr().writer().print("theme \"{s}\" not found\n", .{theme_name});
+        std.os.exit(1);
+    };
+
+    lang_override = res.args.lang;
 
     const stdout_file = std.io.getStdOut().writer();
     var bw = std.io.bufferedWriter(stdout_file);
@@ -58,7 +72,10 @@ pub fn main() !void {
 }
 
 fn render_file(a: std.mem.Allocator, writer: anytype, content: []const u8, file_path: []const u8, theme: *const Theme) !void {
-    const parser = try syntax.create_guess_file_type(a, content, file_path);
+    const parser = if (lang_override) |name|
+        try syntax.create_file_type(a, content, name)
+    else
+        try syntax.create_guess_file_type(a, content, file_path);
 
     const Ctx = struct {
         writer: @TypeOf(writer),
@@ -175,6 +192,11 @@ fn get_theme_by_name(name: []const u8) ?Theme {
     return null;
 }
 
+fn list_themes(writer: anytype) !void {
+    for (themes.themes) |theme|
+        try writer.print("{s}\t{s}\n", .{ theme.name, theme.description });
+}
+
 fn set_ansi_style(writer: anytype, style: Theme.Style) !void {
     const ansi_style = .{
         .foreground = if (style.fg) |color| to_rgb_color(color) else .Default,

src/syntax.zig

@@ -33,6 +33,11 @@ pub fn create(file_type: *const FileType, a: std.mem.Allocator, content: []const
     return self;
 }
 
+pub fn create_file_type(a: std.mem.Allocator, content: []const u8, lang_name: []const u8) !*Self {
+    const file_type = FileType.get_by_name(lang_name) orelse return error.NotFound;
+    return create(file_type, a, content);
+}
+
 pub fn create_guess_file_type(a: std.mem.Allocator, content: []const u8, file_path: ?[]const u8) !*Self {
     const file_type = FileType.guess(file_path, content) orelse return error.NotFound;
     return create(file_type, a, content);