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more ramblings in readme

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maartenkeijzer 2005-10-06 22:26:59 +00:00
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eo/contrib/mathsym/README
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@ -70,6 +70,32 @@ The directory 'fun' contains the functionality for the function and terminal set
with ERC's etc. fun/FunDef.cpp contains the definition of the functionality. Stuff can be
added here, but best to contact me if you miss particular functions.
With the sym and the function set in place, some fairly nice overloading is possible. A quick tour:
To create a variable that reads the first value from the inputs, do:
Sym var = SymVar(0);
To create a constant of value 0.4432, do
Sym cnst = SymConst(0.4432);
The constants are also stored uniquely so that:
Sym cnst2 = SymConst(0.4432)
will lead to:
cnst == cnst2
to be true (this happens without value compare, they point to the same element in the hashtable)
To add two values, do
Sym sym = var + const;
This will create a tree with tree nodes. All other operations work identically.
=== Evaluation (eval/) ===
The second important thing is evaluation. Although Syms can be evaluated through an interpreter,
@ -118,7 +144,7 @@ The three compilation functions can be found in eval/sym_compile.h
A limiting factor in tinycc is that the struct TCCState that is used to hold the compilation context,
is not really self-contained. This unfortunately means that with every call to 'compile' ALL previous
pointers that have been produced are invalidated. I'm still looking at ways to circumvent this.
pointers that have been produced become unsafe for use. I'm still looking at ways to circumvent this.
To work with mathsym, a few small changes in tccelf.c were necessary, check README.TCC for details.