WEBVTT 00:00:00.700 --> 00:00:07.909 By the end of this lesson, you will have a small HHY program saved on your computer and running from the 00:00:07.909 --> 00:00:08.252 terminal. 00:00:08.402 --> 00:00:16.402 We will install the command, check which version we are using, create a dot hhy file, and run it twice. 00:00:16.552 --> 00:00:20.584 The goal is a repeatable starting point for every later lesson. 00:00:20.734 --> 00:00:26.686 Keep the terminal open beside your editor so each small change gets immediate feedback. 00:00:28.840 --> 00:00:37.915 The documented installer supports Apple silicon macOS, Linux on sixty four bit Intel or AMD, and Linux on 00:00:37.915 --> 00:00:38.419 arm. 00:00:38.569 --> 00:00:43.731 Use the installation section of the manual if your machine needs another route. 00:00:43.881 --> 00:00:51.220 These commands are shell commands, so enter them in a terminal, not inside the HHY source file. 00:00:51.370 --> 00:00:53.994 You need network access for the download. 00:00:54.144 --> 00:00:59.733 The default install uses your own home directory and does not require sudo. 00:01:01.880 --> 00:01:06.637 Download the official installer and run it with the course version selected. 00:01:06.787 --> 00:01:11.758 Saving the installer first also lets you inspect it before execution. 00:01:11.908 --> 00:01:19.033 The version variable here applies to the installer command; it keeps this course on one known baseline. 00:01:19.183 --> 00:01:26.299 The installer detects the platform, downloads the release and its checksum, and verifies the archive 00:01:26.299 --> 00:01:27.247 before installing. 00:01:27.397 --> 00:01:31.579 Wait for it to finish successfully before moving to the next command. 00:01:33.730 --> 00:01:40.642 Add the default command directory to this terminal session, then ask the shell where it finds hhy. 00:01:40.792 --> 00:01:42.477 Finally, print the version. 00:01:42.627 --> 00:01:46.873 For these examples the target is one point seven point zero. 00:01:47.023 --> 00:01:51.695 If a different installation appears first, the path check helps you notice it. 00:01:51.845 --> 00:01:54.341 The export lasts for this shell session. 00:01:54.491 --> 00:02:00.443 To keep it for future terminals, add that export to the startup file appropriate to your shell. 00:02:02.590 --> 00:02:05.811 Create a small folder and open it in your editor. 00:02:05.961 --> 00:02:11.615 Save the two line program as hello dot hhy, using a plain text file. 00:02:11.765 --> 00:02:16.927 The extension matters because it helps you and the tooling recognize the source. 00:02:17.077 --> 00:02:23.307 An editor integration is helpful for highlighting, but the command line is enough for this lesson. 00:02:23.457 --> 00:02:29.985 Keep source code in the file and shell commands in the terminal; they are different inputs with different 00:02:29.985 --> 00:02:30.347 jobs. 00:02:32.500 --> 00:02:37.385 The first line creates a binding named language and gives it a string value. 00:02:37.535 --> 00:02:39.157 The second calls print. 00:02:39.307 --> 00:02:42.379 The plus signs join strings into one message. 00:02:42.529 --> 00:02:49.633 We use explicit concatenation in these examples so the result is reproducible on the tested runtime. 00:02:49.783 --> 00:02:52.940 There is no need to memorize every detail yet. 00:02:53.090 --> 00:03:00.063 For now, identify the name, the quoted text, and the function that sends the completed message to the 00:03:00.063 --> 00:03:00.450 terminal. 00:03:02.600 --> 00:03:05.224 Save the file before running these commands. 00:03:05.374 --> 00:03:12.905 Check asks HHY to validate syntax and core semantics; execution actually runs the program. 00:03:13.055 --> 00:03:20.148 A successful check is useful, but it does not prove that every future file read or network request will 00:03:20.148 --> 00:03:20.521 work. 00:03:20.671 --> 00:03:23.103 Here our program only prints text. 00:03:23.253 --> 00:03:27.413 You should see Hello, HHY, with an exclamation mark. 00:03:27.563 --> 00:03:33.622 The run subcommand is another spelling: hhy run followed by the same file name. 00:03:35.770 --> 00:03:40.634 If the shell says command not found, investigate the command path first. 00:03:40.784 --> 00:03:44.731 That error happens before HHY reads your program. 00:03:44.881 --> 00:03:54.225 If HHY cannot find hello dot hhy, check the current directory with pwd and list the files with ls. 00:03:54.375 --> 00:03:59.452 A file called hello dot hhy dot txt is a different name. 00:03:59.602 --> 00:04:05.042 Separating shell problems from program problems will save time throughout the course. 00:04:05.192 --> 00:04:09.224 Correct one thing, then repeat the smallest relevant command. 00:04:11.370 --> 00:04:15.551 For the exercise, change the greeting and add a second print call. 00:04:15.701 --> 00:04:19.093 Save, run, and compare the output with your prediction. 00:04:19.243 --> 00:04:26.229 Then close and reopen the terminal and make sure hhy is still discoverable; if needed, finish the 00:04:26.229 --> 00:04:28.694 persistent path setup for your shell. 00:04:28.844 --> 00:04:34.583 The downloadable example contains the original program and its expected output. 00:04:34.733 --> 00:04:41.538 Next we will use bindings, values, and collections to represent something more useful than a greeting.