Unit Description

Authors

Joe Starr, Ph.D.

I specialize in computational knot theory. I’m also a professional embedded software engineer.

Class Diagram

classDiagram
   prod_weighted --> production 
   prod_weighted *-- prod_weighted_config_t
  prod_weighted_config_t *-- prod_weighted_pair_t
   class prod_weighted{ }

   class prod_weighted_config_t{
   prod_weighted_pair_t* replacement_list
   int replacement_len 
   prod_weighted_pair_t* term_list
   int term_len
   }

   class prod_weighted_pair_t{
   char * string 
   int weight 
   }

   class production{<<interface>>}

Interfaces

Production

Libraries

None

Functionality

Public Structures

Configuration Structure

The configuration structure for the weighted production includes all the data needed for a basic string replacement production as well as a weight for each configured string.

This includes:

A pointer to a list of pointers to replacement strings and weights.
The number of replacement strings and weights.
A pointer to a list of pointers to terminal strings and weights.
The number of terminal strings and weights.

Public Functions

Resolve Function

The resolve function for the weighted production essentially follows the basic production flow. The only difference is a string is randomly selected based on its weighting.

For a list of string weight pairs $\LS \LP s_i, w_i\RP\RS_i^n $, the weighted selection of a string is accomplished by simulating an array of length $\Sigma w_i$. In the simulated array each string $s_i$ is represented $w_i$ times.

Terminate Function

The terminate function for the weighted production essentially follows the basic production flow. The only difference is a string is randomly selected based on its weighting.

For a list of string weight pairs $\LS \LP s_i, w_i\RP\RS_i^n $, the weighted selection of a string is accomplished by simulating an array of length $\Sigma w_i$. In the simulated array each string $s_i$ is represented $w_i$ times.

Validation

Resolve Function

Positive Tests

A valid configuration is passed to the function

A valid configuration for the production is passed to the function.

Inputs:

A valid configuration:
2 strings one with weight 1 and one with weight 2
1 string with weight 1

Expected Output:

A positive response, with the strings in the correct ratio.

Negative Tests

Bad Configuration

A null configuration for the computation is passed to the function.

Inputs:

A null configuration.
A null replacement list.
A zero length replacement list.
Weights whose sum overflows an uint64.

Expected Output:

A negative response.

Terminal Function

Positive Tests

A valid configuration is passed to the function

A valid configuration for the production is passed to the function.

Inputs:

A valid configuration:
2 strings one with weight 1 and one with weight 2
1 string with weight 1

Expected Output:

A positive response, with the strings in the correct ratio.

Negative Tests

Bad Configuration

A null configuration for the computation is passed to the function.

Inputs:

A null configuration.
A null terminal list.
A zero length terminal list.
Weights whose sum overflows an uint64.

Expected Output:

A negative response.