implement a shell of the cli

Author: lukewilliamboswell

build.zig

@@ -0,0 +1,26 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build) void {
+    const target = b.standardTargetOptions(.{});
+    const optimize = b.standardOptimizeOption(.{});
+
+    const exe = b.addExecutable(.{
+        .name = "roc",
+        .root_source_file = b.path("src/main.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+
+    b.installArtifact(exe);
+
+    const run_cmd = b.addRunArtifact(exe);
+
+    run_cmd.step.dependOn(b.getInstallStep());
+
+    if (b.args) |args| {
+        run_cmd.addArgs(args);
+    }
+
+    const run_step = b.step("run", "Build and run the roc cli");
+    run_step.dependOn(&run_cmd.step);
+}

build.zig.zon

@@ -0,0 +1,13 @@
+.{
+    .name = "roc",
+    .version = "0.0.0",
+    .minimum_zig_version = "0.13.0",
+    .dependencies = .{},
+    .paths = .{
+        "build.zig",
+        "build.zig.zon",
+        "src",
+        "LICENSE",
+        "LEGAL_DETAILS",
+    },
+}

src/main.zig

@@ -0,0 +1,91 @@
+const std = @import("std");
+const mem = std.mem;
+const Allocator = std.mem.Allocator;
+
+const usage =
+    \\Usage:
+    \\
+    \\  roc [options] [roc_file] [args]
+    \\  roc [command] [options]
+    \\
+    \\Commands:
+    \\
+    \\  build           Build a binary from the given .roc file, but don't run it
+    \\  test            Run all top-level `expect`s in a main module and any modules it imports
+    \\  repl            Launch the interactive Read Eval Print Loop (REPL)
+    \\  format          Format a .roc file or the .roc files contained in a directory using standard Roc formatting
+    \\  version         Print the Roc compiler’s version, which is currently built from commit 90db3b2db0, committed at 2025-01-28 18:26:51 UTC
+    \\  check           Check the code for problems, but don’t build or run it
+    \\  docs            Generate documentation for a Roc package
+    \\  glue            Generate glue code between a platform's Roc API and its host language
+    \\
+    \\General Options:
+    \\
+    \\ -h, --help       Print command-specific usage
+;
+
+pub fn fatal(comptime format: []const u8, args: anytype) noreturn {
+    std.log.err(format, args);
+    std.process.exit(1);
+}
+
+pub fn log(
+    comptime level: std.log.Level,
+    comptime format: []const u8,
+    args: anytype,
+) void {
+    const prefix = comptime level.asText();
+
+    // Print the message to stderr, silently ignoring any errors
+    std.debug.print(prefix ++ ": " ++ format ++ "\n", args);
+}
+
+pub fn main() !void {
+    var general_purpose_allocator = std.heap.GeneralPurposeAllocator(.{}){};
+    defer {
+        _ = general_purpose_allocator.deinit();
+    }
+    const gpa = general_purpose_allocator.allocator();
+
+    var arena_instance = std.heap.ArenaAllocator.init(gpa);
+    defer arena_instance.deinit();
+    const arena = arena_instance.allocator();
+
+    const args = try std.process.argsAlloc(arena);
+
+    return mainArgs(gpa, arena, args);
+}
+
+fn mainArgs(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
+    _ = gpa;
+    _ = arena;
+
+    if (args.len <= 1) {
+        std.log.info("{s}", .{usage});
+        fatal("expected command argument", .{});
+    }
+
+    const cmd = args[1];
+    // const cmd_args = args[2..];
+    if (mem.eql(u8, cmd, "build")) {
+        log(.info, "TODO roc build", .{});
+    } else if (mem.eql(u8, cmd, "test")) {
+        log(.info, "TODO roc test", .{});
+    } else if (mem.eql(u8, cmd, "repl")) {
+        log(.info, "TODO roc repl", .{});
+    } else if (mem.eql(u8, cmd, "format")) {
+        log(.info, "TODO roc format", .{});
+    } else if (mem.eql(u8, cmd, "version")) {
+        log(.info, "TODO roc version", .{});
+    } else if (mem.eql(u8, cmd, "check")) {
+        log(.info, "TODO roc check", .{});
+    } else if (mem.eql(u8, cmd, "docs")) {
+        log(.info, "TODO roc docs", .{});
+    } else if (mem.eql(u8, cmd, "glue")) {
+        log(.info, "TODO roc glue", .{});
+    } else if (mem.eql(u8, cmd, "help") or mem.eql(u8, cmd, "-h") or mem.eql(u8, cmd, "--help")) {
+        return std.io.getStdOut().writeAll(usage);
+    }
+
+    fatal("subcommand not yet implemented", .{});
+}

test.roc

@@ -0,0 +1,7 @@
+app [main!] { pf: platform "https://github.com/roc-lang/basic-cli/releases/download/0.19.0/Hj-J_zxz7V9YurCSTFcFdu6cQJie4guzsPMUi5kBYUk.tar.br" }
+
+main! = |_|
+    if Bool.true then
+        return Err(Exit(1,"This is a test error message"))
+    else
+        Ok({})