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Dylan and OIL(SCP)
Hi,
Recently because of work, I learned i2 supply chain planner
(SCP) product.
In SCP, there is an interactive scripting language OIL (object
interaction language).
I like the syntax very much. Maybe we can support similar syntax in
Dylan.
I think that everyone know how slot reference works in Dylan.
(<=> is equivalent.) For getter,
A.B <=> B(A).
For setter,
A.B := C <=> B(A) := C <=> B-setter(C, A).
For the getter, it is the same as Dylan. For the setter,
A.set_B(C) <=> set_B(A,C).
There is no A.B := C syntax in SCP.
In SCP, one of the reason which I like their syntax because it is easier
to write deep class hierarchy.
For example, in SCP
(Expression A)
supply_chains.find("My supply chain").plans.find("Actual
plan").horizon.start
is equivalent to
(Expression B)
start(
horizon(
find(
plans(
find(supply_chains,
"My supply chain")
), "Actual plan")
)
)
In my opinion, Expression A is much easier to read and write than
Expression B.
In fact, it seems to me that, Expression A is not allowed in Dylan.
QUESTION: More explicitly, can we define A.B(C) is Dylan?
I think: Since Dylan uses method dispatch, we need to define B(A,C)
method. We can't define B(C) as member function to class A.
If we need to write valid Dylan syntax, it will be similar to Expression
B.
In fact, Expression A can be understood by listener if the following
expressions
are equivalent.
A.B(C,...) <=> B.(A, C, ...).
I don't know how difficult it is to modify the compiler to use this kind
of syntax.
There are several points that I think we can make Dylan more dynamic.
1. Has load-file("file_name.dylan").
I really like these features.
2. More dynamic to evaluate the Dylan codes.
For example,
define B = "foe";
define code = "A." & B & " := C;";
(Assume & is concatenating.)
evaluate(code) will yield
A.foe : = C;
This kind of feature appears in Perl.
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