Implement Conversion of Espon Plaintext format

Epson has an example format for receipts that looks like it can be parsed and converted into binary format.

See: https://download4.epson.biz/sec_pubs/pos/reference_en/escpos/receipt.html

If anyone wants to take a stab at it and send a pull request, I'm happy to bring it in.

Rough idea for the parsing:

Remove comments (start with '//)
Split on whitespace but honor whitespace in quotes.
Quoted tokens are string literals
Check the token against a map (Example, ESC would convert to 1B)
Check if the token starts with 0x and convert from the hex.
Otherwise token is decimal

Map

'// ============================================================================
'// Issuing receipts
'// ============================================================================

'// Initialize printer
    ESC "@"

'// --- Print stamp --->>>
'// Set line spacing: For the TM-T20, 1.13 mm (18/406 inches)
    ESC "3" 18
'// Set unidirectional print mode: Cancel unidirectional print mode (Unnecessary
'// in the TM-T20, so it is comment out)
'//   For models equipped with the ESC U command, implementation is recommended.
'//   Designate unidirectional printing with the ESC U command to get a print
'//   result with equal upper and lower parts for the stamp frame symbol
'//    ESC "U" 1
'// Select justification: Centering
    ESC "a" 1

zachzurn / thermal

Implement Conversion of Espon Plaintext format #22