OpenEuphoria

Re: Structures; etc.

• Posted by Lee West <leewest at ALTAVISTA.COM> Jan 31, 2000
• 506 views

Hi All,

I've been following the recent commentary on structures and OOP, especially
as it relates to preprocessors. Personally, I don't understand some of the
concerns that invoking these techniques via a preprocessor would somehow
negatively impact Euphoria's processing speed... or cause the "type"
command to be used. I have put together a simple example of a record
structure that could be processed by a preprocessor and the Euphoria code
that would result. It certainly doesn't require that the "type" command be
used, therefore, I can't see where the performance degradation would occur.

As to whether this is preferable or even desirable... I'll let you decide.
But it does present an alternative to the, so called, MISSING language
elements of Euphoria, without the performance penalties that may occur if
they were incorporated into the Eu code itself. I believe an implementation
of this type is completely feasible, and can even see the possibility of a
full implementation of an OOP option as well. I'd love to hear your
thoughts. The example follows:

-----------------------
-- Define a record type
record Employee
  Phone        integer
  -- This is an embeded record type in the Employee record
  record Name
    First      string
    Last       string
  end record
  Amount       real
  WeeklyCnt    array[1..4] of integer
end record

-- Define a record variable of the type Employee
eeRecord Employee

-- Define a pointer to the record
RecNo pointer

-- Create a new instance of the record type
RecNo = eeRecord.New

-- Populate the new record using DOT notation
eeRecord[RecNo].Phone        = 1112223333
eeRecord[RecNo].Name.First   = "John"
eeRecord[RecNo].Name.Last    = "Doe"
eeRecord[RecNo].Amount       = 1000.00
eeRecord[RecNo].WeeklyCnt[1] = 25

-- Create another instance of the record type
RecNo = eeRecord.New

-- Populate the new record
eeRecord[RecNo].Phone        = 2223334444
eeRecord[RecNo].Name.First   = "Jane"
eeRecord[RecNo].Name.Last    = "Doe"
eeRecord[RecNo].Amount       = 2000.75
eeRecord[RecNo].WeeklyCnt[3] = 25

--------------------------------------------
-- PreProcess the above code and generate --
-- the following Euphoria code            --
--------------------------------------------

-- Define the variables
sequence temp, eeRecord
constant
  Phone     = 1,
  Name      = 2,
  NameFirst = 1,
  NameLast  = 2,
  Amount    = 3,
  WeeklyCnt = 4

-- Define the record counter
integer RecNo
RecNo     = 0

-- Initialize the record and record template
eeRecord = {}
temp     = {0,{"",""},0.0,{0,0,0,0}} -- Based on the record definition

-- Populate the first eeRecord
eeRecord = append(eeRecord,temp)
RecNo += 1
eeRecord[RecNo][Phone]           = 1112223333
eeRecord[RecNo][Name][NameFirst] = "John"
eeRecord[RecNo][Name][NameLast]  = "Doe"
eeRecord[RecNo][Amount]          = 1000.00
eeRecord[RecNo][WeeklyCnt][1]    = 25
-- Populate another occurrence of the eeRecord
eeRecord = append(eeRecord,temp)
RecNo += 1
eeRecord[RecNo][Phone]           = 2223334444
eeRecord[RecNo][Name][NameFirst] = "Jane"
eeRecord[RecNo][Name][NameLast]  = "Doe"
eeRecord[RecNo][Amount]          = 2000.75
eeRecord[RecNo][WeeklyCnt][3]    = 15

-- Print the record
include print.e
print(1,eeRecord)
-- The following is printed
-- {{1112223333,{"John","Doe"},1000,{25,0,0,0}},{2223334444,
{"Jane","Doe"},2000.75,{0,0,15,0}}}


Thanks. Lee.