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Berkeley Logo has limited support for non-English-speaking users. Alas, there is no Unicode support, and high-bit-on ASCII codes work in some contexts but not others.
If you want to translate Berkeley Logo for use with another language, there are three main things you have to do:
1. Primitive names 2. Error (and other) messages 3. Documentation
For primitive names, the easiest thing is to provide a startup file that
defines aliases for the English primitive names, using
COPYDEF "AVANT "FORWARD
This should take care of it, unless your language's name for one primitive
is spelled like the English name of a different primitive. In that case
you have to turn
REDEFP on and be sure to copy the non-conflicting name
before overwriting the conflicting one!
"Primitives" that are actually in the Logo library, of course, can just be replaced or augmented with native-language-named Logo procedures and filenames.
Of course Logo programs will still not look like your native language if the word order is dramatically different, especially if you don't put verbs before their objects.
For error messages, there is a file named ‘Messages’ in the
‘logolib’ directory with texts of messages, one per line. You can
replace this with a file for your own language. Do not add, delete, or
reorder lines; Logo finds messages by line number. The sequences
%t in these messages represent variable parts of the
message and should not be translated. (%p
SHOWs it – that is, the difference is about whether or not
brackets are shown surrounding a list. %t means that the variable part is a C
text string rather than a Logo object.) If you want to change the order of
two variable parts (no reorderable message has more than two), you would for
example replace the line
%p doesn't like %s as input
%+s is a lousy input to %p
The plus sign tells the message printer to reverse the order; you must
reverse the order of %p and %s, if both are used, to match. The plus
sign goes just after the first percent sign in the message, which might
not be at the beginning of the line. The sequence
\n in a message
represents a newline; don't be fooled into thinking that the
n is part
of the following word.
Some messages appear twice in the file; this isn't a mistake. The two spaces
I don't know how\ \ to aren't a mistake either.
The message containing just
%p is for user-provided error messages in
THROW "ERROR. The message "
\ \ in %s\n%s" is the part of all
error messages that indicates where the error occurred if it was inside a
procedure; you might want to change the word
in to your language.
%s defined\n is what
LOAD prints for each procedure defined
if the variable
to %p\nend\n\n" is what
EDIT puts in the temporary file if
you ask to edit a procedure that isn't already defined.
Also in the ‘Messages’ file are lines containing only one word each; the
first of these is the word
true. Some of these words are recognized by
Logo in user input; some are generated by Logo; some are both. For example,
FALSE are recognized as Boolean values by
IFELSE, and are also generated by Logo as outputs from
the primitive predicates such as
EQUALP. The word
recognized as the end of a procedure definition, and may be generated when
Logo reconstructs a procedure body for
EDIT. I've used
capital letters in this paragraph for easier reading, but the words in the
‘Messages’ file should be in lower case.
If you replace these with non-English words, Logo will recognize both the
English names and your alternate names. For example, if you replace the
vrai then Logo will understand both of these:
IF "TRUE [PRINT "YES] IF "VRAI [PRINT "YES]
UseAlternateNames determines whether Logo will
generate other-language names – for example, whether predicate
functions return the other-language alternates for
FALSE. This variable is
FALSE by default, meaning that the
English words will be generated.
You might wish to have English-named predicate functions generate English
FALSE, while other-language-named predicates generate
the alternate words. This can be done by leaving
false, and instead of defining the other-language predicates with
COPYDEF, do it this way:
to french.boolean :bool if equalp :bool "true [output "vrai] if equalp :bool "false [output "faux] output :bool ; shouldn't happen end to make.french.predicate :french :english :arity define :french `[[[inputs] ,[:arity]] [output french.boolean apply ,[word "" :english] :inputs]] end ? make.french.predicate "egal? "equal? 2 ? pr egal? 3 4 faux ? pr egal? 4 4 vrai ? pr equal? 3 4 false ? pr equal? 4 4 true
The third input to
make.french.predicate is the number of inputs that
the predicate expects. This solution isn't quite perfect because the infix
>) will still output in English. If
you want them to generate alternate-language words, set
Some of the words in this section of the ‘Messages’ file are names of
Logo primitives (
.MACRO). To translate these
names, you must use
COPYDEF as described earlier, in addition to
changing the names in ‘Messages’. You should be consistent in these two
steps. Don't forget the period in
For documentation, there are two kinds: this manual and the help files.
The latter are generated automatically from this manual if you have a
Unix system, so in that case you need only translate this manual,
maintaining the format. (The automatic helpfile generator notices
things like capital letters, tabs, hyphens, and equal signs at the
beginnings of lines.) The program
makefile.c may require modification
because a few of the primitive names are special cases (e.g.,
the only name with digits included).
If you don't have Unix tools, you can just translate each helpfile
individually. A period in a primitive name is represented as a
the filename; there are no files for question marks because the
command looks for the file named after the corresponding primitive
that ends in
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This document was generated by Brian Harvey on September, 3 2008 using texi2html 1.78.