2 Extract marked strings in your code

With the previous example, you may extract the translations:

(import (po-lib))

(define (main)
  "Say the line."
  (display (gettext "Hello, world!"))
  (newline))

(dynamic-xgettext
  #f
  "myproject"
  "0.0"
  "msgid-bugs@myproject"
  main)

What this will do is return a list of template translations, starting with a header with all the information, and then all translations that were used when calling main with no argument.

Function: dynamic-xgettext domain project-name project-version bug-report-address f ¶

Return multiple values: a list of template translations with a header first, and all values returned by f called with no arguments.

The extraction is dynamic, because strings within dead code will not be detected. It may be difficult to exercise all the translations in a complex program however.

Macro: with-marked-strings domain code ... ¶

Prematurely register all the occurences of calls to gettext or mark-string and then expand code in the same lexical scope. Even the messages in deep rarely used code branches will thus be marked for translations, provided the lexical scope of the expansion of with-marked-strings is reached during the dynamic-xgettext invocation.

For instance,

(dynamic-xgettext #f "example" "0.0.0" "test@example.org"
  (lambda ()
    (when #f
      (display (gettext "Oh no, a rare condition occured!")))))

will return a translation with only the header template, because the useful branch is never reached, while

(dynamic-xgettext #f "example" "0.0.0" "test@example.org"
  (lambda ()
    (with-marked-strings #f
      (when #f
        (display (gettext "Oh no, a rare condition occured!"))))))

will return 2 translations templates: the header template, and the message “Oh no, a rare condition occured!”.