`1` ```exercism fetch lua ocr-numbers ```

# OCR Numbers

Given a 3 x 4 grid of pipes, underscores, and spaces, determine which number is represented, or whether it is garbled.

# Step One

To begin with, convert a simple binary font to a string containing 0 or 1.

The binary font uses pipes and underscores, four rows high and three columns wide.

 ```1 2 3 4``` ``` _ # | | # zero. |_| # # the fourth row is always blank ```

Is converted to "0"

 ```1 2 3 4``` ``` # | # one. | # # (blank fourth row) ```

Is converted to "1"

If the input is the correct size, but not recognizable, your program should return '?'

If the input is the incorrect size, your program should return an error.

# Step Two

Update your program to recognize multi-character binary strings, replacing garbled numbers with ?

# Step Three

Update your program to recognize all numbers 0 through 9, both individually and as part of a larger string.

 ```1 2 3 4``` ``` _ _| |_ ```

Is converted to "2"

 ```1 2 3 4``` ``` _ _ _ _ _ _ _ _ # | _| _||_||_ |_ ||_||_|| | # decimal numbers. ||_ _| | _||_| ||_| _||_| # # fourth line is always blank ```

Is converted to "1234567890"

# Step Four

Update your program to handle multiple numbers, one per line. When converting several lines, join the lines with commas.

 ```1 2 3 4 5 6 7 8 9 10 11 12``` ``` _ _ | _| _| ||_ _| _ _ |_||_ |_ | _||_| _ _ _ ||_||_| ||_| _| ```

Is converted to "123,456,789"

## Running the tests

To run the tests, run the command `busted .` from within the exercise directory.

## Further information

For more detailed information about the Lua track, including how to get help if you're having trouble, please visit the exercism.io Lua language page.

## Source

Inspired by the Bank OCR kata http://codingdojo.org/cgi-bin/wiki.pl?KataBankOCR

## Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.