Origami is the Japanese art of paper folding, creating shapes like animals just by folding paper. Origami instructions have a lot in common with computer programs. They are sequences of instructions that must be followed exactly and in the right order.
Origamists (people who do origami) follow origami instructions. Computers also follow instructions – ones given in programs. Instructions that must be followed, whether by a computer or a human, have to be very clear and precise. English and other human languages aren’t very good for this. It is too easy to misunderstand what you are actually meant to do. Both origami instructions and programs are therefore written in special languages.
The symbols used in origami diagrams are agreed world-wide so that any origamist can follow them. For example, a looping arrow at the side of a diagram means turn the whole piece of paper over. A dashed line means create a ‘valley fold’ along the line. That means fold the paper up into a mountain valley shape (see the diagram) before flattening the two parts together. Arrows show where the paper is to be folded to. Having symbols that mean precise, agreed things also means that an origami design can be created by anyone, whatever language they actually speak: Japanese, English, Arabic …
Computers follow instructions too
Programming languages solve the same problems. Different kinds of computer have their own basic set of instructions – their own machine language. That is the language they can actually follow. Programs are written in ‘high-level’ programming languages. They are languages halfway between human languages and computer languages (see Sorry to Bug You, page 6). They use words and symbols like ‘=’ or ‘IF’ that have special meanings in the language just as Origami symbols have special meanings.
An example valley fold instruction
Can you follow the sequence of steps exactly and make this Origami Bunny? You start with a square sheet of paper.