CompAnn--User Manual

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CompAnn—User Manual

This is the user manual for CompAnn and Anne language description. Technical details and internals are described in another document.

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1 cann—The Anne Compiler

cann is the compiler that translates the programming language Anne (see Anne) into neural networks. cann is a command-line utility.

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1.1 Basic Usage

cann's usage is very basically oriented at gcc's:

cann [FLAGS] INPUT -o OUTPUT [--sam-dump SAM]

This call compiles the Anne-file INPUT and saves the resulting network to OUTPUT. Optionally (mainly for debugging of the compiler itself) can be requested to dump the SAM tree (as readable text) to the file SAM.

General options allowed as FLAGS:

Displays copyright- and version-information for cann.
Displays a short usage-summary.

Additionally allowed are the flags for optimization, See cann Optimization.

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1.2 Requesting Optimization

To enable compiler optimization fully or partially (only some algorithms), the following flags can be used:

Enable all optimization algorithms.
Enable BitSharing.
Enable Compactor optimization.

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2 rann—The ANN-Interpreter

rann is an interpreter for programs in form of ANNs generated by cann.

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2.1 Usage of rann

The usage of rann is basically the following:


This call loads the network ANN and executes it. The input arguments passed to the network can be specified directly on the command-line as a sequence of numbers as ARGUMENTS. If that is not or only partially done, the program will ask interactively for the missing values. After the successful execution all output-values are written to stdout.

Flags allowed:

Display copyright- and version-information for rann.
Display a short usage-summary.
Enables collecting of runtime-statistics (see rann Statistics).

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2.2 Collecting Runtime-Statistics

rann is able to collect runtime-statistics during the execution of ANNs. This is great for testing and optimizing the performance of both the compiler itself (and the effectiveness of optimizations) and the Anne-sources of the ANNs.

If statistics are enabled via the command-line flag (see rann Usage), the collected values are dumped to stdout after the execution. Values collected:

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3 The Programming Language Anne

Anne is a procedural, structured programming language specifically designed to be compilable into ANNs. The syntax is vaguely based on C but often differes from C or refers to language constructs not existent in C; the description of very C-like syntax however is kept very briefly.

All identifiers, keywords and things like that are handled case-sensitive.

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3.1 Basic Language Elements

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Comments are in Anne both in classical C-multi-line-syntax and in one-line syntax as per C++ and Java possible:

     /* This is a
     multi-line comment */
     // This is a one-line comment

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3.1.2 Literals for Numbers and Booleans Numbers

Numbers must be notated in decimal notation without sign or decimal point, that is, simply a sequence of digits:

     c=04567; // Possible, but nicht octal!
     d=0xABC; // Invalid
     e=-.5e2; // Invalid Booleans

For boolean values the corresponding numbers 0 and 1 can be used as well as the “constants” true and false.

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3.1.3 Identifiers

IDs are identifiers for “named things” like variables or calls. They may consist of alpha-numeric characters, but the first character must not be a digit.

Valid IDs are `abc123', `DanielKraft' or `fooBar', invalid are `0fun', `abc.def' or `daniel_kraft'.

Also invalid are reserved keywords as those are recognized by the parser as keywords and not IDs.

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3.1.4 Types

At the moment there's only one flavour of data-types in Anne: unsigned integers with arbitrary bit-size. The corresponding type is identified by uintn, where n is the desired number of bits.

With two's complement notation and some corresponding operators one can however also use those numbers as signed if needed.

     variable uint16 a; // 16-bit unsigned integer (uint16_t)
     variable uint1  b; // boolean value
     variable uint64 c; // 64-bit unsigned integer (uint64_t)
     variable uint4  d; // 4-bit unsigned integer, range 0-15

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3.1.5 Reserved Keywords

The following words are reserved in Anne having some special meaning described in other sections of this manual:

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3.2 Basic Structure of an Anne Program

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3.2.1 Input- and Output-Arguments

The head of an Anne-program lists all input- followed by the output-arguments of the program. Such a definition follows the syntax:

     inout type name;

where inout is depending on the type of definition either input or output, type the data-type of the defined argument and name the ID used to reference it later.

     input uint4 inNum;
     input uint1 inBool;
     output uint16 outNum;
     output uint1 outBool;

If no input- or output-arguments are needed, the corresponding definitions part can be skiped.

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3.2.2 Callback Definitions

After the arguments one can define callbacks to be used in the program. A callback is somewhat a “native” method that has to be implemented by the runtime-environment and can be used for more complex interaction as is possible by simply passing arguments. The syntax for such a definition is:

     callback name(in1, in2...) -> (out1, out2...);

name is the identifier for the callback, inN the type of the N-th callback input-argument and outN the type of the N-th output argument. If there's exactly one output argument the parentheses can be omitted. For a callback entirely without output arguments that's not possible!

     callback sum(uint4, uint4) -> uint5;
     callback nothing() -> ();
     callback swap(uint8, uint8) -> (uint8, uint8);

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3.2.3 Global Variables

At this point global variables may be defined; the syntax is the same as for argument definitions (see Anne InOutArgs), but variable is used as keyword.

     variable uint6 flags;

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3.2.4 The Main Code

Not like most other languages where the main code is either in a special marked area (or a function like main) or the code present outside of every procedure, in Anne there has to be exactly one statement (see Anne Statement) after the header that is used as entry-point. This of course can be a code block (Anne Block) to allow a sequence of statements as program code.

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3.3 Expressions—Values in Anne

An expression is everything that has a value (sometimes called Rvalues); they are no commands or statements of themselves but parts of those.

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3.3.1 Constant Values

A literal (see Anne Literal) can be used as expression:

     a=42;   // ``42'' is an expression
     b=true; // as is ``true''

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3.3.2 Variable References

A variable (and equivalently an input- or output-parameter) can be referenced by its name; the value of an expression like this is of course the variable's value.

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3.3.3 Operations and Calculations

Of course Anne also allows operations and calculations by combining sub-expressions with operators. Possible operators in decreasing order of priority:

Value of a—parentheses can be used to override default priority.
Binary “not” of a.
The numerically negative value of a.
a incremented by one (a+1).
Binary “XOR”, “and” or “or” of a and b.
Arithmetic sum or difference of a and b.
Left- or right-shift of a by n binary digits—n has to be a compile-time constant.
0 or 1 depending on the comparison's result.
0 or 1 depending on the comparison's result.

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3.4 Lvalues—Targets for Assignments

Lvalues are “objects” that can be assigned a (new) value, but they do not necessarily have to also have a value (that is, they need not be Rvalues). Not even after an assignment has taken place.

However, in Anne only variable-references are possible Lvalues (see Anne Expression Variable) which are expressions, too, so this detail is “hidden”.

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3.5 Statements—Commands in Anne

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3.5.1 Assignments

Assignments are written in Anne as in many other programming languages; an expression gets assigned to an lvalue.


Short-hand assignments as in C-like languages are also possible, here of course the target must be lvalue and expression together. Possible operators for this are: &, |, ^, +, -, << and >>.


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3.5.2 Calling Procedures

A Call (to a procedure or callback) can be used as statement, too, optinally the return-values can be assigned to some lvalues after the call returns.

The call itself is written as usual, and if return-values are expected, the operator -> followed by the lvalue-targets (in parentheses if more than one) should follow it. It is both possible to specify less lvalues than there are return-values and to skip some return-values in the middle of the list.

     sum(3, 4) -> a;
     swap(a, b) -> (a, b);
     swap(4, 3) -> (, c); // c is now 4

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3.5.3 If-Then-Else Conditionals

If-Then- and If-Then-Else statements are the constructs for conditional execution in Anne. The syntax is similar to C:

     } else

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3.5.4 Loops in Anne

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While-Loops are loops whose body is repeated as long a certain condition is true:

     // While until overflow

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Do-While-Loops are also repeated until some condition gets false, but this condition is checked at their end so they get executed at least once:

     // Infinite loop

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3.5.5 Jumps and Loop-Controlling

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Labels name jumping targets; unlike in C they need not be followed by a statement as they generate their own NOP statement (that has no performance costs of course).

See Anne Goto for example.

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The keyword goto followed by a label name allows for direct, simple jumps:

       goto ende;
     goto label;

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The command break ends a loop currently executed immediatelly, it's simply a jump after the loop's end.

An optional constant n specified along with break determines which of a set of nested loops will be ended. The inner-most n loops will be cancelled.

           break 2;

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continue cancells the current loop iteration and proceeds immediatelly with the next iteration. Like with break a constant may be specified to identify one of several nested loops, See Anne Break.

     // Infinite loop

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3.5.6 Blocks

Often its useful to place a sequence of statements instead of a single one at some position (for instance if the body of a loop or conditional should consist of more than one statement). This is done via a block notated in curly braces:


Inside a block local variables may be declared (similarly to global variables, see Anne VarDecls); those are valid only inside that block. If other variables of the same name are already declared in a parent scope, they are shadowed by the new ones.

       variable uint4 local;
         variable uint8 local;
         local=128; // 8-bit variable
       local=128;   // Overflow, only 4 bits here
       variable uint6 i;

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3.5.7 Multi-Threading Asynchronous Execution

The simplest form of multi-threading on the Anne-level is asynchronous execution; here, some statement is simply executed in parallel to the current line of execution (that of course can be a block, too, see Anne Block).

This form is very cheap as there are no runtime- and space-costs, but it is not suitable for all purposes.

Such a asynchronous statement is introduced with the keyword asynchronous:

     // Both assignments in parallel, only the time of one needed!
     b=42; Parallel Execution

For parallel execution, two or more statements are really executed in parallel; the program continues after the block once all those statements are finished.

This flavour of multi-threading costs a bit runtime and a few neurons, but is much more flexible and safe than asynchronous execution. Here one need not know at compile-time which of the parallel lines will be the longest.

Such a block is written after the keyword parallel in curly braces. All statements that are directly within this block are executed in parallel.

     // Three assignments of different durations in parallel

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Appendix A GNU Free Documentation License

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replace the "with...Texts." line with this:

    with the Invariant Sections being LIST THEIR TITLES, with the
    Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.

If you have Invariant Sections without Cover Texts, or some other
combination of the three, merge those two alternatives to suit the

If your document contains nontrivial examples of program code, we
recommend releasing these examples in parallel under your choice of
free software license, such as the GNU General Public License,
to permit their use in free software.