Thinkums

Execution

co-routines
either call directly and yield a specific result, or just use as xxx
threads
...

Limitations

Values may have limitations (constraints), types derived from other types which only have a greater set of contraints are called subtypes.
discriminant values.
How to test parameterized modules if the params match the constraints? Like is this an enum and does it have a 'equals'?

Primitive properties

.base (base type? ADA)
.succ(), .pred() next/prious value of
Have an explicit modular thing to allow wraparounds?

Comparing

Is 'x' a wrapper for its value (like strings), or is 'x' a specific thing with identity unlike another 'y' which has identical values.

Value names and constness

Make distinction between const values which can be copied into source, and const variables which can't (defined in lib and lib can change...)

Floating point

David Goldberg, "What Every Computer Scientist Needs To Know About Floating Point Arithmetic," ACM Computing Surveys, vol. 23, pp. 5-48, 1991.

VMs

Read about 'mono' (qv .Net)

Loop access

By default 'current element' in a loop is weakly 'const'. Declare as alterable to overwrite (and change the value of the current element)

Functions

method def
'final', always virtual, private (always static)>/dd>
alias
...
'weak' pointers/functions
...
part
To label stuff (?)
Access
priority
indirect
The last argument of the function must be an object of type Function. When the indirect function is called, then the function passed as the last argument is called instead. The function to be called is expected to have a prototype compatible with the indirect one.
Casting related flags (for more details, read the introduction to Pliant casting mechanism):
implicit
extension
reduction
explicit
Junction
A 'scalar' which has more than one value.
These values an be The operation will be executed on each item, but with

Program Specialization and Partial Evaluation

Program specialization, also known as partial evaluation, is an automatic tool for program optimization, similar in concept to but in several ways stronger than a highly optimizing compiler. It is a source-to-source staging transformation: program pgm together with partial data s are transformed into an often faster specialized version pgm-s by precomputing parts of pgm that depend only on s.

Ideas from Blue

Builtin to indicate compiler extension (floats?)
Type-equality
set support
'super' calls different not dot notation? How about module.routine?

Ideas from C#

Enum as always prefixed with their enum type name: enum foo (bar); foo.bar;
'Collection' objects which can do foreach
Attributes???
Namespace support
Delegates are vulnerable (see here

Ideas from D

Synchronized functions and blocks (using a mutex)
Reread later: modules

Ideas from Ruby

Inplace change indicated by '!'