iteration-composition.xml Iteration, composition Traditional loop constructs (while, until, etc.) plus the Lisp "named let" (a generalization of FOR) plus functional iteration (repeated invocation of a function) and function composition.
list-utilities.xml List utilities Some standard functions on lists (append, reverse, etc.)
stream-tools.xml Streams (lazy lists) A variation on the list data type in which each list item aren't computed until it's needed, so you can construct million-item lists without really taking up all that time or memory, or even infinite-sized lists. (A block that reports all the prime numbers is included as an example.)
variadic-reporters.xml Variadic reporters Versions of +, x, AND, and OR that take more than two inputs.
httpBlocks.xml Web services access (https) An extended version of the HTTP:// block that allows POST, PUT, and DELETE as well as GET requests, allows using the secure HTTPS protocol, and gives control over headers, etc.
word-sentence.xml Words, sentences One of the big ideas in Logo that they left out of Scratch is thinking of text as structured into words and sentences, rather than just a string of characters. This library (along with the JOIN WORDS block in the Tools library) brings back that idea.
cases.xml Multi-branched conditional (switch) Like "switch" in C-like languages or "cond" in Lisp. Thanks to Nathan Dinsmore for inventing the idea of a separate block for each branch!
leap-library.xml LEAP Motion controller Report hand positions from LEAP Motion controller (leapmotion.com).
setrgb.xml Set RGB or HSV pen color Set or report pen color as RGB (red, blue, green) or HSV (hue, saturation, value).
penTrails.xml Save and restore pictures drawn by pen Save and restore lines drawn and costumes stamped on the stage, or make a sprite costume from saved pen trails.
try-catch.xml Catch errors in a script Run a script; if an error happens, instead of stopping the script with a red halo, run another script to handle the error. Also includes a block to cause an error with a message given as input. Also includes a block to create a script variable and give it a value.
multiline.xml Allow multi-line text input to a block In general, text inputs allow only a single line. The MULTILINE block accepts multi-line text input and can be used in text input slots of other blocks.
