Lab 3, Part 1: Using Oz/Mozart IDE

Transcription

1 Lab 3, Part 1: Using Oz/Mozart IDE February 22, 2012 Using Oz/Mozart can be done in 2 ways: 1. interactive programming with OPI (Oz Programming Interface) (oz) 2. compiling Oz programs with Oz compiler (ozc) and running with Mozart VM (ozengine) The first method is very handful when learning Oz and the second is used for creating executable programs on disk. We first learn how to use OPI and later how to compile and run Oz programs. 1 Using the OPI The OPI uses the Emacs editor as the programming front-end. In order to succesfully use OPI you have to study the basics of Emacs editor, e.g. how to copy/paste text or open/save files. Type oz on the command line which opens Emacs editor (see Figure 1) with a buffer 1 in Oz mode 2. The other buffer is the output of Oz interactive compiler. 1.1 Emacs basics In this section we will learn how to use basic Emacs functionality. You can type text in Emacs buffer just like in any contemporary text editor. However, the way to do other actions in Emacs is quite different. It is not better or worse, just different, get used to it :) Exit Open File Exit Emacs from the main menu. As you can see it has keyboard shortcut hint (C-x C-c) 3 that you can use instead. If you do not have unsaved (file related) buffers or active processes the Emacs quits immediately. In our case there are some Oz tools running, so you will be asked for confirmation in minibuffer 4. Type yes and press Enter to exit. Try it with C-x C-c but wait for a second after you press C-x. As you will see, C-x will appear in the minibuffer which shows things you typed up to this moment. Now press C-c to complete the key sequence and exit Emacs. As you will see key sequences are very common in Emacs. 1 buffer in Emacs is a document instance which may(or may not) be related to a file on disk 2 mode in Emacs defines buffer look (e.g. syntax highlighting) and behavior (e.g. keyboard shortcuts) 3 hold Control key and press x and c keys in sequence 4 minibuffer is one-line buffer at the bottom 1

2 Figure 1: OPI just after opening Copy/paste In other text editors Shift key is usually used to select text for copying. In Emacs you define region 5 1. by setting the mark by pressing C-SPC to define start of the region and then 2. moving the point 6 to define end of the region. The selected text will be highlighted as on the Figure 2. Now press M-w 7 for copying or C-w for cutting. Move to another location and press C-y 8 for pasting. You can also use left mouse button to select region and Edit menu to copy/paste text. Cancelling It is often required to cancel some actions you started. For example, you wanted to copy text, so you pressed C-SPC and moved the point but suddenly decided not to copy it. In such (and many other) cases C-g is helpful. In some cases C-g does not help then try ESC-ESC-ESC (escape button three times). Undo/redo The undo in Emacs is done with C-_ (Control underscore) 9. Unlike other editors redo in Emacs is the undo of undo, so to redo after undo 5 selected text in Emacs is called region 6 the position of text cursor in Emacs is called point 7 hold the Alt key and press w, M stands for Meta which is Alt key for PC 8 y stands for yank, which is how pasting is called in Emacs 9 on estonian keyboard press Control Shift - 2

3 Figure 2: Region, highlighted with yellowish background 1. press some other key other than C-_ (e.g. C-g or right arrow) to cancel undoing 2. press C-_ again to redo The behavior is different than with typical undo/redo functionality but you only notice it if doing undo/redo of the same text several times. Searching text C-s starts incremental search, type phrase to search, C-s for next match, any other key to stop search at current position, C-g to cancel search. C-r does the reverse search. Saving/loading files Saving buffer in Emacs is done with C-x C-s and giving file name in minibuffer (see Figure 3). Press TAB to auto-complete file name, press TAB again to get the list of possible completions, press TAB again if the list is too long. Finish typing file name and press Enter to save the buffer or C-g to cancel saving. Visiting 10 (loading) file in Emacs is done with C-x C-f. As with saving you can use TAB for completion. Working with buffers There are usually many buffers opened in Emacs at the same time. Type C-x b to switch buffer in current window, insert buffer s name, use TAB for completion as with files. To close a buffer type C-x k, insert buffer name (current buffer is default), and press Enter. If the buffer is connected with file but not saved then you ll be asked for confirmation. Look under Buffers main menu for some more commands. Working with windows There are 2 windows in the Emacs frame 11 upon start of oz. One window can only contain (part of) one buffer. 10 visit is like load except that it creates new file if one does not exist 11 Emacs frame is OS window and Emacs window splits Emacs frame into parts 3

4 Figure 3: Saving buffer in Emacs Type C-x 2 to split current window horizontaly into 2 windows. Use C-x o to move between windows. Use C-x 3 to split current window vertically. Type C-x 1 to leave only one (current) window in frame. Use mouse to move between windows or resize windows. Executing commands Emacs is written almost completely in Emacs lisp (elisp). It has many commands that you can run interactively type M-x and insert command into minibuffer, e.g. goto-line, then enter line number and press Enter. Getting help C-h is a standard prefix for help commands in Emacs. For example, C-h m describes current mode (including keyboard shortcuts). (Type C-x o to jump to the window with help buffer, C-x k to close the help buffer) Type C-h? to see possible help options. C-h t opens fine Emacs tutorial. 1.2 OPI basics Work through the online tutorial about OPI tutorial/node2.html Notice that you can indent line with TAB anywhere on the line 4

5 indent region by selecting the region and pressing C-M-\ 12 2 Running Oz compiler and VM It is possible to compile and run usual statements with ozc -e and compile and pickle expressions with ozc -c. The problem is that none of them have access to the sytem modules. 2.1 Compile a functor You need to define and compile functors (module definitions in Oz) which are compiled by ozc and later read and linked by ozengine to system libraries. 1. Visit Oz file hello.oz (C-x C-f ) and type in the program functor import System Application define {System.show Hello } {Application.exit 0} end 2. Save the file (C-x C-s) 3. run ozc -c hello.oz to get hello.ozf with Oz functor 4. run ozengine hello.ozf to execute the program 2.2 What is functor Functors are just syntactic sugar for special expression in Oz. If you wonder what functor is then you can use ozc --expression -o - -E hello.oz to output functor expression in Oz kernel language to standard output. Do not be scared, the definition will be more clear after the next lab is completed. 3 Using Mozart documentation On the Mozart/Oz documentation page there are several interesting tutorials 1. Oz tutorial for starting learning Oz 2. Distributed Programming in Mozart for the second half of this course 12 on estonian keyboard press 4 keys: Control Alt AltGrp + 5

6 3. Application Programming some example applications, mainly distributed, which show how to program with Mozart functors 4. High-level Window Programming with QTk Mozart GUI built on top of Tk 5. Window Programming with Tk lower level GUI interface 6. Open Programming in Mozart files, sockets, etc several reference manuals 1. The Oz Base Environment procedures for built-in types, e.g. String.toInt, List.append, List.forAll, List.foldL, etc. 2. System Modules command line arguments, operating system functions like time, files and sockets, GUI programming and many more 3. The Mozart Standard Library some additional helpful libraries but not too much 4. Some documentation on Programming Environment and Tools, eg debugger and profiler 5. Loop support syntactic sugar for looping constructs that work with recursion Several things to notice in the documentation Base environment modules, e.g. Float or List, do not need to be imported Some procedures are bound to global variables by default, e.g. List.forAll is bound to ForAll, which is shorter alternative this can be seen from the documentation: if its name starts from upper case then it is bound to the global variable with the same name Some procedures are bound to global variables from non-base modules, but in OPI only! System.show is bound to Show Browser.browse is bound to Browse Documentation marks parameter types with symbols and required/output parameters with + and? read Type Structure and Description Format 6