Refactor builtin commands dispatcher

src/builtin/builtin.zig

@@ -8,16 +8,22 @@ const exit = @import("cmds/exit.zig");
 const pwd = @import("cmds/pwd.zig");
 const run = @import("cmds/run.zig");
 
-pub const Shell = struct {
-    running: bool = true,
-    interrupted: bool = false,
-    environ: *const std.process.Environ.Map,
-};
+const types = @import("types.zig");
+
+const CommandFn = *const fn (types.BuiltinCommandContext) anyerror!void;
+
+const commands = std.StaticStringMap(CommandFn).initComptime(.{
+    .{ "cd", cd.execute },
+    .{ "pwd", pwd.execute },
+    .{ "run", run.execute },
+    .{ "echo", echo.execute },
+    .{ "exit", exit.execute },
+});
 
 pub fn execute(
     io: std.Io,
     allocator: std.mem.Allocator,
-    shell: *Shell,
+    shell: *types.Shell,
     command: parser.Command,
 ) !bool {
     if (command.argv.len == 0)
@@ -25,30 +31,15 @@ pub fn execute(
 
     const name = command.argv[0];
 
-    if (std.mem.eql(u8, name, "cd")) {
-        try cd.execute(io, shell.environ, command.argv);
-        return true;
-    }
+    const execute_fn = commands.get(name) orelse
+        return false;
 
-    if (std.mem.eql(u8, name, "pwd")) {
-        try pwd.execute(io, allocator);
-        return true;
-    }
+    try execute_fn(.{
+        .io = io,
+        .allocator = allocator,
+        .shell = shell,
+        .argv = command.argv,
+    });
 
-    if (std.mem.eql(u8, name, "run")) {
-        try run.execute(io, allocator, command.argv);
-        return true;
-    }
-
-    if (std.mem.eql(u8, name, "echo")) {
-        try echo.execute(io, command.argv);
-        return true;
-    }
-
-    if (std.mem.eql(u8, name, "exit")) {
-        exit.execute(&shell.running);
-        return true;
-    }
-
-    return false;
+    return true;
 }

src/builtin/cmds/cd.zig

@@ -1,20 +1,18 @@
 const std = @import("std");
 
-pub fn execute(
-    io: std.Io,
-    environ: *const std.process.Environ.Map,
-    argv: []const []const u8,
-) !void {
-    const path = if (argv.len >= 2)
-        argv[1]
+const types = @import("../types.zig");
+
+pub fn execute(ctx: types.BuiltinCommandContext) !void {
+    const path = if (ctx.argv.len >= 2)
+        ctx.argv[1]
     else
-        environ.get("USERPROFILE") orelse environ.get("HOME") orelse {
+        ctx.shell.environ.get("USERPROFILE") orelse ctx.shell.environ.get("HOME") orelse {
             std.debug.print("xsh: cd: cannot find home directory\n", .{});
             return;
         };
 
-    var dir = try std.Io.Dir.cwd().openDir(io, path, .{});
-    defer dir.close(io);
+    var dir = try std.Io.Dir.cwd().openDir(ctx.io, path, .{});
+    defer dir.close(ctx.io);
 
-    try std.process.setCurrentDir(io, dir);
+    try std.process.setCurrentDir(ctx.io, dir);
 }

src/builtin/cmds/echo.zig

@@ -1,16 +1,15 @@
 const std = @import("std");
 
-pub fn execute(
-    io: std.Io,
-    argv: []const []const u8,
-) !void {
-    for (argv[1..], 0..) |argument, index| {
+const types = @import("../types.zig");
+
+pub fn execute(ctx: types.BuiltinCommandContext) !void {
+    for (ctx.argv[1..], 0..) |argument, index| {
         if (index != 0) {
-            try std.Io.File.stdout().writeStreamingAll(io, " ");
+            try std.Io.File.stdout().writeStreamingAll(ctx.io, " ");
         }
 
-        try std.Io.File.stdout().writeStreamingAll(io, argument);
+        try std.Io.File.stdout().writeStreamingAll(ctx.io, argument);
     }
 
-    try std.Io.File.stdout().writeStreamingAll(io, "\n");
+    try std.Io.File.stdout().writeStreamingAll(ctx.io, "\n");
 }

src/builtin/cmds/exit.zig

@@ -1,3 +1,5 @@
-pub fn execute(running: *bool) void {
-    running.* = false;
+const types = @import("../types.zig");
+
+pub fn execute(ctx: types.BuiltinCommandContext) !void {
+    ctx.shell.running = false;
 }

src/builtin/cmds/pwd.zig

@@ -1,12 +1,11 @@
 const std = @import("std");
 
-pub fn execute(
-    io: std.Io,
-    allocator: std.mem.Allocator,
-) !void {
-    const path = try std.process.currentPathAlloc(io, allocator);
-    defer allocator.free(path);
+const types = @import("../types.zig");
 
-    try std.Io.File.stdout().writeStreamingAll(io, path);
-    try std.Io.File.stdout().writeStreamingAll(io, "\n");
+pub fn execute(ctx: types.BuiltinCommandContext) !void {
+    const path = try std.process.currentPathAlloc(ctx.io, ctx.allocator);
+    defer ctx.allocator.free(path);
+
+    try std.Io.File.stdout().writeStreamingAll(ctx.io, path);
+    try std.Io.File.stdout().writeStreamingAll(ctx.io, "\n");
 }

src/builtin/cmds/run.zig

@@ -2,31 +2,29 @@ const std = @import("std");
 
 const script = @import("../../script/script.zig");
 
-pub fn execute(
-    io: std.Io,
-    allocator: std.mem.Allocator,
-    argv: []const []const u8,
-) !void {
-    if (argv.len < 2) {
+const types = @import("../types.zig");
+
+pub fn execute(ctx: types.BuiltinCommandContext) !void {
+    if (ctx.argv.len < 2) {
         std.debug.print("xsh: run: missing script path\n", .{});
         return;
     }
 
-    var file = try std.Io.Dir.cwd().openFile(io, argv[1], .{});
-    defer file.close(io);
+    var file = try std.Io.Dir.cwd().openFile(ctx.io, ctx.argv[1], .{});
+    defer file.close(ctx.io);
 
-    var file_reader = file.reader(io, &.{});
+    var file_reader = file.reader(ctx.io, &.{});
 
     const source = try file_reader.interface.allocRemaining(
-        allocator,
+        ctx.allocator,
         .limited(16 * 1024 * 1024),
     );
 
-    const name_z = try allocator.dupeZ(u8, argv[1]);
+    const name_z = try ctx.allocator.dupeZ(u8, ctx.argv[1]);
 
     try script.run(
-        allocator,
-        io,
+        ctx.allocator,
+        ctx.io,
         name_z,
         source,
     );

src/builtin/types.zig

@@ -0,0 +1,14 @@
+const std = @import("std");
+
+pub const Shell = struct {
+    running: bool = true,
+    interrupted: bool = false,
+    environ: *const std.process.Environ.Map,
+};
+
+pub const BuiltinCommandContext = struct {
+    io: std.Io,
+    allocator: std.mem.Allocator,
+    shell: *Shell,
+    argv: []const []const u8,
+};

src/main.zig

@@ -5,6 +5,7 @@ const parser = @import("shell/parser.zig");
 const execute = @import("shell/execute.zig");
 
 const builtin = @import("builtin/builtin.zig");
+const builtin_types = @import("builtin/types.zig");
 
 const script = @import("script/script.zig");
 
@@ -14,7 +15,7 @@ pub fn main(init: std.process.Init) !void {
     const allocator = init.gpa;
     const io = init.io;
 
-    var shell = builtin.Shell{
+    var shell = builtin_types.Shell{
         .environ = init.environ_map,
     };
 
@@ -55,7 +56,7 @@ pub fn main(init: std.process.Init) !void {
     }
 }
 
-fn runPipeline(allocator: std.mem.Allocator, io: std.Io, shell: *builtin.Shell, source: []const u8) !void {
+fn runPipeline(allocator: std.mem.Allocator, io: std.Io, shell: *builtin_types.Shell, source: []const u8) !void {
     const tokens = try lexer.lex(allocator, source);
     const command = try parser.parse(allocator, tokens.items);
 

src/shell/execute.zig

@@ -1,13 +1,14 @@
 const std = @import("std");
 
 const builtin = @import("../builtin/builtin.zig");
+const builtin_types = @import("../builtin/types.zig");
 
 const parser = @import("parser.zig");
 
 pub fn run(
     io: std.Io,
     allocator: std.mem.Allocator,
-    shell: *builtin.Shell,
+    shell: *builtin_types.Shell,
     command: parser.Command,
 ) !void {
     if (try builtin.execute(io, allocator, shell, command))