Limits and the game's editor

A thousand instructions, four hundred buffer characters, 256 draw commands — limits are worth knowing before you hit them

mediumYou need: Writing in the game, What an instruction costs

The limits you run into

What	Limit
instructions in a program	1000
labels in the text form	500
characters in the print buffer	400
draw commands before drawflush	256
a processor’s links	by the block’s radius, not by count
slots in a memory cell	64, in a memory bank — 512

A thousand instructions is a lot: nobody writes that many by hand. The people who hit it are those who assemble a program with something else — a compiler or a generator.

Silent failure

The excess does not fit, silently. Line one thousand and one simply will not go into the program, draw command two hundred and fifty-seven will not go into the buffer, character four hundred and one will not go into the text. And there will be no error.

So a long program is checked by the fact: look at the last line in the editor — is it there? The print buffer — sensor @bufferSize? Drawing — count the commands yourself.

The game’s editor and everything else

The processor window is a block editor: dragging, dropdowns, jump arrows. It is good while the program fits in your head, and agony when it has three hundred lines.

That is why it has a second door — “Edit code”: the same thing as text. In it:

• a program can be pasted in whole from the clipboard;
• labels work instead of line numbers;
• bulk changes are easy — search and replace in any text editor.

Note

Text and blocks are the same program. On opening, the block editor parses the text; on saving it assembles the text again out of blocks, and whatever it did not understand turns into an empty line. That is exactly how labels, comments and extra spaces disappear.

How to move a program

Where to	How
to another processor on the same map	copy the text through “Edit code”
to another map	the same — text is not tied to a map
together with the blocks	as a schematic: the processor is copied along with its program and links

A schematic is the only way to move a program with its links: the names cell1, duo1 are preserved in it if the blocks move along. Text copied on its own remembers no links at all: you will have to set them up again, and the order will be different.

Silent failure

Links do not survive copying text. cell1 is not a block’s name but a number in this processor’s link list. Move the program and cell1 now points at whatever is connected first, and that could be anything.

It is worth checking straight away: getlink and @links will show how many links there are and which.

What the game’s editor does not have

• a search through the program. In three hundred lines you have to look with your eyes;
• comments that survive. You can write a comment: in the text form the game skips everything after # to the end of the line. But open the program as blocks and save it, and the editor assembles the text anew — out of blocks — and the comments disappear along with the labels;
• a debugger. There is only the variable window; there are no breakpoints and no stepping through lines — you have to imitate them yourself, with wait and printing to a message block;
• an edit history. There is no undo: erased is erased.

Hence the habit of the experienced: keep the program as text outside the game, edit it in an ordinary editor and paste it in whole.

Remember

• The limits: 1000 instructions, 500 labels, 400 buffer characters, 256 draw commands.
• Everything in excess is dropped silently.
• “Edit code” is the same program as text; labels live only there.
• A program is moved as text, and links only as a schematic.
• Comments (#) live only in the text and are lost when saving from blocks.
• There is no search, no debugger and no undo in the editor.