Related Syntax
Data type conversion

You can convert data from one type to another in OmniMark in a number of ways.

String-to-number conversion

You can convert a string to an integer value simply by using the string value where an integer is expected. OmniMark coerces the string value to an integer automatically. The string used must contain only decimal digits.

  ; stream-to-integer.xom
  process
     local stream foo initial {"6"}
     local integer bar initial {7}
     set bar to bar + foo
     output "Bar = " || "d" % bar
  ; Output: Bar = 13

You can convert a string representation of a BCD number to a BCD by preceding the string value with the keyword bcd:

  ; stream-to-bcd.xom
  include "ombcd.xin"
  process
      local stream foo initial {"12.75"}
      local bcd bar initial {"0.25"}
      set bar to bar + bcd foo
     output "Bar = " || "d" % bar
  ; Output: Bar = 13

You can convert a string representation of a floating point number to a float OMX type using float.

  ; stream-to-float.xom
  include "omfloat.xin"
  process
      local stream foo initial {"6565.32e+4"}
      local float bar
      set bar to float foo
      output "Bar = " || "d" % bar
  ; Output: "Bar = 65653200"

Number-to-string conversion

You can convert an integer to a string expression using the "d" format item.

  ; integer-to-string.xom
  process
     local integer foo initial {6}
     output "Foo formatted as a string: " || "d" % foo
  ; Output: "Foo formatted as a string: 6"

The "d" format item has many format modifiers that allow you to specify how the number is displayed. For instance, to display a number as two hexadecimal digits, you would use the sequence "16ru2fzd". This sequence means:

• "16r" - display using radix (or base) 16 -- hexadecimal
• "u" - display using uppercase letters for digits over 9
• "2f" - display with a width of 2 digits
• "z" - pad the display with leading zeros
• "d" - the "d" format item

Thus the following code will print "FD":

  process
     local integer foo initial {253}
     output "Integer formatted as string with hex, uppercase, 2 digits, padded: "
         || "16ru2fzd" % foo
  ; Output: "Integer formatted as string with hex, uppercase, 2 digits, padded: FD"

You can convert a BCD value to a string using the BCD template formatting language.

For instance, the following code outputs "$5,729.95":

  include "ombcd.xin"
  process
      local bcd total
      set total to bcd 5729.95
      output "<$,NNZ.ZZ>" % total

You can convert a floating point value to a string using float:

  include "omfloat.xin"
  process
      local stream foo initial {"6565.32e+4"}
      local float bar
      set bar to float foo
      output "d" % bar
  ; Output: 65653200.000000000000000

Converting to and from ASCII values

To get the ASCII code (or EBCDIC code on machines that use it) for an individual character, you can use the binary operator:

  process
     local stream foo initial {"G"}
     output "The ascii code for "
         || foo
         || " is "
         || "d" % binary foo
         || "."

To output the character that corresponds to an ASCII code, use the "b" format item:

  process
     local integer foo initial {71}
     output "The character corresponding to ascii code "
         || "d" % foo
         || " is "
         || "b" % foo
         || "."
  ; Output: "The character corresponding to ASCII code 71 is G."

A simple hex dump program

Here is a simple hex dump program that uses some of these conversion methods to print out side-by-side ASCII and hex representations of a file. In the ASCII representation, unprintable characters are represented by periods:

  declare #main-input has binary-mode
  macro format-2digit-hex is "16ru2fzd" macro-end

  process
      submit #main-input


  find any{1 to 16} => chars
      local integer i initial {0}
      repeat scan chars
          match [" " to "~"]+ => visible
              output visible
          match any
              output "."
      again

      output " " ||* (16 - length of chars)

      repeat scan chars
          match any => char
              output " " || format-2digit-hex % binary char
              increment i
              output " -" when i=8
      again
      output "%n"

Number-to-number conversion

You can convert an integer to a BCD by simply putting "bcd" before the integer name, as shown in this program:

  ; integer-to-bcd.xom
  include "ombcd.xin"
  process
      local integer dollars initial {2}
      local bcd total
      set total to bcd dollars + bcd 729.95
      output "<$NNZ.ZZ>" % total
  ; Output: "$731.95"

You can convert an integer to a floating point data type by simply putting "float" before the integer name, as shown in this program:

  ; integer-to-float.xom
  include "omfloat.xin"
  process
      local integer dollars initial {2}
      local float total
      set total to float dollars + float 729.95
      output "$" || "d" % total
  ; Output: "$731.95"

For information on how to represent hex numbers, octal numbers and others in which you convert a string to a number, see base.

Related Syntax    base    binary

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