Curly braces are now used in Squeak to construct runtime-evaluated collections. For those of you who may not have seen it, Squeak lets you do the following:
1) Runtime-evaluated Collection Brace stacks can be used to create runtime-evaluated arrays almost as easily as literal arrays:
{a. b-3. c squared}
is equivalent to:
Array with: a with: b-3 with: c squared
except that a brace expression can be arbitrarily large without exceeding available with:with:... messages, and without exceeding available stack size.
Any type of collection can be used by adding an as: message:
{a. b-3. c squared} as: OrderedCollection
2) caseOf: statements
Another use of curly braces is to build a runtime collection of block associations for caseOf: statements:
stateMachineState caseOf:
{ [1] -> [(firstByte << 2) bitOr: (secondByte >> 6)].
[2] -> [(firstByte << 6) bitOr: (secondByte >> 2)]}.
Documentation (Redirection)