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## 'Logo' printed from http://nrich.maths.org/

Release Notes
Version 0.6

- Ran regression tests again and discovered that v0.5 had indeed
regressed due to problems with returning values from procedures.
v0.6 fixes these.
- Boolean and Logical operations should be added
- Next release should adddress the two major problems of infix
operator precedence and better handling of recursion depth. A new
tokeniser is in the works for this.

Version 0.5

- Added Pause/Resume to Output panel too.
- New primitives: abs arccos cos radarccos radcos arcsin sin
radarcsin radsin arctan tan radarctan radtan exp ln log10 pi power
sqrt setspeed speed
- show and print nowunderstand parenthesised calls as in (show 1
2 3 4 "five), which displays the list [1 2 3 4 five]
- Fixed a race bug in turtle animation
- Added support for comments . These start with a semicolon and
continue to the end of line.
- Added numeric range checking to primitive calls. e.g. (arccos
-2) will print 'arccos doesn't like -2 as input'.

Version 0.4

- Turtle movements are now animated so you can see them
happening.
- Added Turtle speed control. The fastest speed (10) skips the
animation.
- Added Pause/Resume button
- Fixed bug in 'left'

Version 0.3

- Fixed Run button behaviour

Version 0.2

- (sum 1 2 3) and (product 1 2 3 4) now work. Note that (+ 1 2 3)
returns a syntax error because + is an infix operator. (1 + 2 + 3)
is the equivalent syntax for +. (* is similar)
- Print and Show now mirror MSWLogo behaviour correctly
- There needs to be a separate command panel
- Need Single Step
- Hitting the Run button while the program is running confuses
it.

Version 0.1

- Operator precedence is not supported yet. Use parenthesis. e.g.
(2*3)+4
- The code reader does not distinguish unary minus (negative
numbers) from binary subtraction well and can get confused. Use
parenthesis.
- Recursion is only supported to a depth of 255 calls.
- Load and Save only allow you to save one program
- There is no inbuilt help system yet
- (sum 1 2 3) only sums 1 and 2
- Quite a few primitives are still missing