# Forum

• Aug 19
Re: [eiffel-users] C++ is losing its grip
Thanks for the link. It is probably best to avoid the Register, but read read it to correct a lot of guff they put around (and guff in comments). Here is the comment thread. It is interesting that karlkarl has been voted down about 10 to 1. But I also think it would be interesting to provide an
• Aug 19
Re: [eiffel-users] Re: C++ is losing its grip
I've had to write C++ code for many years...and I never had a grip. On Mon, Aug 19, 2019, 11:25 AM Finnian Reilly wrote: > Hi Ian > I think you are being diplomatic with your title. Perhaps what you really > meant is that C++ programmers are loosing their grip (on reality) 😃
• Aug 19
Re: C++ is losing its grip
Hi Ian I think you are being diplomatic with your title. Perhaps what you really meant is that C++ programmers are loosing their grip (on reality) 😃 I didn't feel like signing up to the register just to read the original post, but I found the news from "the horses mouth" i..e on dropboxes own
• Aug 18
C++ is losing its grip
This is a rather interesting article that DropBox is dropping C++ as a cross-platform language. https://forums.theregister.co.uk/forum/1/2019/08/16/dropbox_gives_up_on_sharing_c_code_between_ios_and_android/?post_received=3850154#c_3850154 I put in a long comment in reply to the regular C++
• Aug 18
An upcoming graphical application created with Eiffel and the Vision-2 libraries
Introducing Matyroshka Over the weekend I held a software reveal and digital art exhibition to show of my new Matryoshka software which I hope to release to the general public by the end of the year, or early 2020. I invited various professional artists, graphic designers and illustrators based
• Aug 18
RE: [eiffel-users] Re: Returning to Eiffel
No. -- BM From: eiffel...@googlegroups.com [mailto:eiffel...@googlegroups.com] On Behalf Of Bernd Schoeller Sent: Sunday, 18 August, 2019 01:43 To: eiffel...@googlegroups.com Subject: Re: [eiffel-users] Re: Returning to Eiffel Hello ECMA people ;-) Just a short question concerning
• Aug 18
Re: [eiffel-users] Re: Returning to Eiffel
I don't think this has been discussed. But it does not work anyway because we also want to be able to call this kind of features in regular object calls: c := {COLOR}.red c := my_color.red So, to follow your suggestion, it should have been: Current = Void or Current /= Void
• Aug 18
Re: [eiffel-users] Re: Returning to Eiffel
That's what I had setup too, though with a snafu: the program name is case sensitive in the XML file so at first StepThree did not match stepthree.exe. But still don't see the other presentation I hope to get. I wonder if there is a hidden switch in the WEL package that does not get properly set
• Aug 17
Re: [eiffel-users] Re: Returning to Eiffel
Hello ECMA people ;-) Just a short question concerning this: Had it been discussed to use 'Current = Void' instead of 'class' ? Why was this dismissed? Regards, Bernd On 29/07/2019 06:17, Bertrand Meyer wrote: This is a recent addition. See https://dev.eiffel.com/EiffelStudio_18.01_Releases.
• Aug 17
Re: [eiffel-users] Re: Returning to Eiffel
YOUR_EXE_NAME
• Aug 17
Re: [eiffel-users] Re: Returning to Eiffel
> Windows didn't seem to pick up the manifest, although tailored according > to > https://docs.microsoft.com/en-us/windows/win32/controls/cookbook-overview , > and dropped side-by-side to the exe, both in workbench mode and in a > finalized version. Still looking for an answer.
• Aug 16
Re: [eiffel-users] Re: Returning to Eiffel
You need the Windows manifest file in the same folder as the EXE. Stupid, I know, but there it is.
• Aug 16
Re: Returning to Eiffel
I created a small window layout in EiffelBuild and generate / compile it. The presentation looks vey different in the run time version than in the develpment presentation. EIffelBuild shows: [image: Main window in EiffelBuild.png] Runtime started out of EiffelStudio (native Windows, not
• Aug 15
Re: Newbie question on code reuse - using a previous project
Thanks for the input, guys. In my case I frequently have several 'experimental' applications, and rarely have a finished 'primary' from which to base the others. I tend to pick the last variant that is closest to my next idea and work from there. I do also have classes that rarely change, and
• Aug 13
Re: Newbie question on code reuse - using a previous project
Management library. Think of it as a library for creating "Swiss-army knife applications". Visit the link for details. You inherit EL_MULTI_APPLICATION_ROOT in your root class. An example of it's use in the root class of project toolkit.ecf: APPLICATION_ROOT Note: currently Eiffel-loop only
• Aug 13
Re: Returning to Eiffel
I guess I have found the relevant discussion to my question at Void-safety: Background, definition, and tools on Eiffel.org.
• Aug 13
Re: [eiffel-users] Re: Newbie question on code reuse - using a previous project
Together with good project organization and the appropriate culling out of classes into small libraries—one also has the notion of project "targets". I have a tool that I built for myself that creates a new project with a minimum of two targets—a primary project target and a test target. What
• Aug 13
RE: [eiffel-users] Re: Newbie question on code reuse - using a previous project
Happens all the time. Well, it happens. First, you should organize your originating project into what is, and isn't reusable. This is always a good exercise and leads to a more robust (read: compulsive) class-oriented/reusable-component mindset, from which you will not likely ever recover. The
• Aug 13
Re: Newbie question on code reuse - using a previous project
Slightly OT (a regular occurrence with me), I often find myself wanting to make a variant of a project, and it would be handy if there was a way to 'copy & rename' a project in a couple of clicks (assuming I haven't missed this option somewhere). At the moment I do this by creating a new project
• Aug 10
Re: Newbie question on code reuse - using a previous project
Hi Hank, As the others have responded, there is a cluster option and a library option. Myself—I tend to the library option, creating many small specialized libraries. I do this in a step-wise fashion—creating a cluster within my project to start and then migrating that cluster out into a
• Aug 10
Re: [eiffel-users] Re: Returning to Eiffel
Is this not why we have SCOOP? On Friday, August 9, 2019 at 2:33:47 PM UTC-4, colinpauladams wrote: > > Probably first_window is an attribute of the class. Then there is the > possibility of multi-threading to take into account (first_window might > become detached on another thread). > > On
• Aug 10
Configuration/version management
The topic of built-in support for configuration management within EiffelStudio comes up regularly. So far the internal view has been that each organization has its own approach to configuration management and that we don’t want to be imposing a particular method or tool. That point was made long
• Aug 10
A question about SCOOP and C
I have been looking through the SCOOP documentation and I couldn't find anything as it relates to making asynchronous calls to C routines via the external keyword. Is it possible? What is the relation of SCOOP to the C world?
• Aug 09
Re: [eiffel-users] Re: Returning to Eiffel
Probably first_window is an attribute of the class. Then there is the possibility of multi-threading to take into account (first_window might become detached on another thread). On Fri, 9 Aug 2019 at 19:20, Richard wrote: > Some words of wisdom, please > > From a
• Aug 09
Re: Returning to Eiffel
Some words of wisdom, please From a VisualEiffel example the main class below with a snippet of interest highlighted in blue. I attempt to replace it by the snippet highlighted in brown. The compiler is cautious on void saftey and marks my code with VUTA(2) (see below). My question: What is
• Jul 24
Eiffel: regular expressions how to do grouping

I'd like to do grouping of regular expressions with eiffel. How do I do something like

l_reg.compile ("^([0-9]{3}) (rabbit[0-9]).*")
l_groups := l_reg.groups ("123 rabbit1")
my_first_rabbit := l_groups.at (2)


Didn't find any example on groups, LX_DFA_REGULAR_EXPRESSION class and other googlings

• Jul 23
Eiffel: how do I do a system call?

Id like to uncompress a file with bzip2 myFile.bz2 which class do I have to use for that?

I tried to find it into base kernel documentation which made the most sense for me and didn't find it

• Jul 19
Eiffel: percent character into a string

How do I concatenate a percent % string to a string?

as either do not work

s := "%%" + s + "%"


I know its a special character but don't afford it neither do I find the doc...

## UPDATE

The answer was one of my attempts, but it could stay an issue of the compiler/editor. After putting the example into the same feature, compiling, and replacing the old code the compiler did not complain anymore, but still stays as syntax coloration strange

• Jul 19
Eiffel: syntax error on multiple Generic constraint

As per this documentation, I'm trying to constrain a Generic parameter to 2 classes and need a default_create creation procedure call in my implementation.

I'm getting a Syntax error from compiler on the select clause. Why is that so?

I thought first that calling default_create will call the G one which could be a merge/renaming/etc. but seems that on that level I have to call either one of both or both renamed which makes sense for me. But why does this syntax fail?

The context and my code is following:

deferred class
IDENTIFIABLE_CASH[G -> {IDENTIFIABLE[ANY],
DB_ENTITY select default_create end} create default_create end]

inherit
DB_SERVICE_CASH[G]

feature -- Access

cash_from_identifier (an_identifier: like {IDENTIFIABLE_DB_ENTITY[ANY]}.identifier): G
-- Returns firt entity found like given an_identifier (like operator is used)
local
l_qry: COMPOSED_SQL_QUERY
do
across
cash is l_item
loop
if l_item.identifier.is_equal(an_identifier) then
Result := l_item
end
end
if not attached Result then
create l_qry.make (item_prototype)
l_qry.add_constraint (create {FIELD_CONSTRAINT}.make (Void, identifier_db_column_name, {CONSTRAINT}.Like_operator, an_identifier))
if items.count > 0 then
Result := items.first
else
create Result
check
item_not_found: False
end
end

cash.extend (Result)
end
end

• Jul 03
Eiffel: Where can I find a reference with common features lists?

Am looking for typical

feature {NONE} -- Initialization (semantic)
feature -- Status Settings (semantic)
.....


Where can I find that list with semantic?

Didn't find it into ECMA

• Jun 29
Eiffel: best way to compare types without getting a catcall

Got a Catcall trying to compare 2 types, how could I do that avoiding passing through another not dedicated method (like to string, class_id or stuff like that)?

## SIT_UTIL

    class_name_lowercase (a_string: STRING): STRING
-- a copy lowercased and pruned from preceding '!'
do
Result := a_string
if Result.index_of('!', 1) = 1 then
Result := Result.substring (2, Result.count)
Result.to_lower
else
Result := Result.as_lower
end
ensure
instance_free: class
end


## CLIENT_CLASS

    relationship_from_secondary_type_equal (a_type: like relationships.item.secondary_type): detachable like relationships.item
-- Returns first instance of found relationship secondary type which equals given one
do
across
relationships as l_rel
until
Result /= Void
loop
--              if attached (a_type / l_rel.item.secondary_type) then -- Don't want conformance but equality

--              if attached (a_type.is_equal (l_rel.item.secondary_type)) then -- tried but as is_equal needs a like Current => Catcall
--              if attached (a_type.equal (a_type, l_rel.item.secondary_type)) then -- Catcall because b signature is like a
if {SIT_UTIL}.class_name_lowercase (a_type).is_equal({SIT_UTIL}.class_name_lowercase (l_rel.item.secondary_type)) then
Result := l_rel.item
end
end
check
not_found_relationship: Result /= Void
end
end

• Jun 29
Eiffel: a way to check type conformance with a given CLASS_NAME

I'm trying to do something as

work (a_father: FATHER)
do
if a_father.conforms_to ({DEVELOPER}) then
a_father.code
else
a_father.change_job ({DEVELOPER})
end
end


the compilation works, but in my implementation @runtime it doesn't pass. What did I mistype?

• Jun 29
Eiffel, multiple types conformance: a way to specify that a parameter is a descendent from A and B?

Is there a way (I'm sure there is out of runtime check...) to specify that a parameter or a variable in general conforms to multiple types? to avoid doing something such as

work (a_printer: PRINTER; a_scanner: SCANNER)
do
a_printer.print
a_scanner.scan
-- OR without second parameter
if attached {SCANNER} a_printer as l_scanner then
l_scanner.scan
else
throw RuntimeError
end
end

• Jun 11
€ Symbol from commandline (Arguments)
• Apr 20
Problems compiling Traffic library

I attempted to install the Traffic library for the book "A Touch of Class" but was not able to compile the examples. EiffelStudio complained about a base2.ecf file. Error code: VD00

General configuration parsing error. What to do: fix the configuration file.

Could not open file: \base2.ecf $EIFFELBASE2\base2.ecf base2.ecf is found in where Windows installed Eiffel: C:\Program Files\Eiffel Software\EiffelStudio 18.11 GPL\unstable\library\base2.ecf The offending line of code seems to be this in the Traffic configuration files: I have attempted to change this configuration file pointing directly to where the file is, using the actual path, to no avail. • Apr 05 Eiffel: passing argument to agent received as argument I'm really stuck in how to pass an argument to a second level of an Eiffel agent call. Hope my example is enough self explaining: main_call do b (agent d(?, ?)) end b (a_proc: PROCEDURE[STRING]) local l_something_else: INTEGER do l_something_else := 1 -- z("a_line", a_proc(l_something_else)) -- How can I pass at this stade l_something_else to the d procedure!!! end d (line: STRING; something_else: INTEGER) do -- do_some_stuff_with_line (line, something_else) do_nothing end z (a_line: STRING; a_proc: PROCEDURE[STRING]) do a_proc.call([a_line]) end  I would have liked to be able to do something like z("a_line", a_proc(?, something_else))  But its not possible, as I try with the agent keyword, the a_proc argument is not recognized! So what would be the syntax? I even tried to add an argument to a_proc with a_proc.set_operands but am lost with the OPEN_ARGS class ## Implementation case If you need a goal... just imagine I'd like to have 2 different implementations of the d function, and in my case its using UT_CSV_HANDLER that I'd like to have 2 different functions for each line of a CVS The following code gives a Non-compatible actual argument in feature call Feature: import_from_csv_impl Called feature: import_from_csv_impl (a_rest_request: REST_REQUEST; a_procedure: PROCEDURE [DS_ARRAYED_LIST [STRING_8], INTEGER_64, STRING_8]): [detachable like items] detachable SIT_LINKED_LIST [MEASURING_POINT] from MEASURING_POI... Argument name: ia_name Argument position: 2 Formal argument type: STRING_8 Actual argument type: INTEGER_64 Line: 258 ia_procedure.call (ia_measuring_point_id, ia_name) -> end (?, l_measuring_point_id, l_s) l_csv_handler.read_file (l_is, l_partially_closed)  The complete example: -- Main call import_from_abb_csv (a_rest_request: REST_REQUEST): detachable like items do Result := import_from_csv_impl (a_rest_request, agent impl_for_each_csv_line_import_from_abb_csv) end -- Second call import_from_csv_impl (a_rest_request: REST_REQUEST; a_procedure: PROCEDURE[DS_ARRAYED_LIST [STRING_8], INTEGER_64, STRING]): detachable like items local l_csv_handler: UT_CSV_HANDLER l_is: KL_STRING_INPUT_STREAM l_measuring_point_id: INTEGER_64 l_s: STRING l_partially_closed: PROCEDURE[DS_ARRAYED_LIST[STRING]] do l_s := "whatever" l_measuring_point_id := 12 create l_csv_handler.make_with_separator (',') l_partially_closed := agent (i_al: DS_ARRAYED_LIST[STRING]; ia_measuring_point_id: INTEGER_64; ia_name: STRING; ia_procedure: PROCEDURE[INTEGER_64, STRING]) do ia_procedure.call (ia_measuring_point_id, ia_name) end (?, l_measuring_point_id, l_s) l_csv_handler.read_file (l_is, l_partially_closed) end -- end call impl_for_each_csv_line_import_from_abb_csv (a_csv_line: DS_ARRAYED_LIST [STRING_8]; a_measuring_point_id: INTEGER_64; l_cu_name: STRING) do -- do_my_business end -- for information signature of read_file is: -- read_file (a_file: KI_TEXT_INPUT_STREAM; a_action: PROCEDURE [DS_ARRAYED_LIST [STRING]])  • Apr 05 Eiffel: type conformance, how to give a type instead of an instance ## General I don't understand why there are like 2 generating_type kinds, the one with exclamation point, and the other not. ## My case I have a function returning a DB_SERVICE[G] from a given instance from a collection of db_services so that from another service I can retrieve it and call it. When I pass an instance generating_type to that function, the conforms_to returns True, as when I give ({ENUMERATE}).generating_type it doesn't. Why is that so? -- Humanly unreadable if attached {ENUMERATE_DB_SERVICE} {SIT_ENVIRONMENT}.app_instance.db_service_from_entity_type (item_prototype.charge_unit_relationship.secondary_prototype.an_index_relationship.secondary_prototype.generating_type) as l_enum_dbs then -- Humanly readable but not working if attached {ENUMERATE_DB_SERVICE} {SIT_ENVIRONMENT}.app_instance.db_service_from_entity_type (({ENUMERATE}).generating_type) as l_enum_dbs then  My function db_service_from_entity_type (an_entity_type: TYPE[detachable DB_ENTITY]): detachable like db_services.item do across db_services as l_dbs until Result /= Void loop if l_dbs.item.item_prototype.generating_type.conforms_to (an_entity_type) then Result := l_dbs.item end end ensure service_found: attached Result end  ## Edit (20190405-11:26 UTC) As the screenshot shows, giving {ENUMERATE} instead of ({ENUMERATE}).generating_type doesn't work either • Mar 29 Eiffel: Creating a datetime with '' format Seems I'm wrong creating a datetime from string using this method, any idea why? The precondition violates on date_time_valid: date_time_valid (s, code) create l_date_time.make_from_string ("2019-03-28T15:28:02Z", "yyyy-mm-ddThh:mi:ssZ")  • Mar 10 Eiffel shortest statement for object creation and result of function If I'd like to add a DATE_TIME to a logger for example I'd like to avoid creating a local variable for that. Is there any similar statement as create {DATE_TIME}.make_now.formatted_out ("yyyy-mm-dd hh:mi:ss")  which is not possible? • Feb 18 Eiffel: a way to display assertion violation on runtime of executable As I have the choice on finalizing a project to keep assertions, I'd think that assertion violation would be shown or displayed on console (hopefully on stderr on linux). What would be the proper way to do such, like seems that I have to add it or enable something to get it... • Feb 11 Eiffel: how do I set the command line arguments of an autotest? Some of my tests needs something like {EXECUTION_ENVIRONMENT}.arguments.separate_character_option_value ('l')  to be attached (not Void), how do I set commandline arguments to eiffel autotest? • Feb 11 Eiffel: a proper way to inherit from a class and convert Current object to it It's not the first time I'm trying to inherit from a class and convert an object to it, in this case extend functionalities of HTTP_CLIENT_RESPONSE with valid_http_response => response.status = 200, valid_http_json_body => validate json content, etc... For that, I'd like to inherit from HTTP_CLIENT_RESPONSE and add features and create my custom DB_ENTITY_HTTP_CLIENT_RESPONSE from an HTTP_CLIENT_RESPONSE test_case local l_http_client_r: HTTP_CLIENT_RESPONSE l_db_entity_http_client_r: DB_ENTITY_HTTP_CLIENT_RESPONSE do l_http_client_r := execute_get("someURL") -- returns an HTTP_CLIENT_RESPONSE l_db_entity_http_client_r := l_http_client_r assert("valid response", l_db_entity_http_client_r.valid_response) end  it seems I've difficulties having the internal properties set... what would be the best way to do this? I had the same case trying to create a WATT class inheriting from NATURAL_32 which is an expanded. In my strategy, I tried to call in creator • a parent creation procedure • then call a deep_copy Here is the rest of my class attempt: class DB_ENTITY_HTTP_CLIENT_RESPONSE inherit HTTP_CLIENT_RESPONSE create make_from_http_client_response convert make_from_http_client_response ({HTTP_CLIENT_RESPONSE}) feature -- Initialization make_from_http_client_response (a_client_response: HTTP_CLIENT_RESPONSE) do make (a_client_response.url) deep_copy (a_client_response) end feature -- Status report valid_response: BOOLEAN do Result := status = 200 end  The only way I found working for now is by setting all attributes to other which is the semantic of deep_copy normally... make_from_http_client_response (a_client_response: HTTP_CLIENT_RESPONSE) do make (a_client_response.url) set_body (a_client_response.body) set_http_version (a_client_response.http_version) set_error_occurred (a_client_response.error_occurred) set_error_message (a_client_response.error_message) set_raw_header (a_client_response.raw_header) set_status_line (a_client_response.status_line) ... I surely forgot something... end  • Feb 10 Eiffel: is there a way with do_all or do_if to search for an element in a collection without having to write a whole feature? across collection as l_item until Result /= Void loop if l_item.item.name.is_equal ("foo") then Result := l_item.item end end  is there a way and if so which one to do something like collection.do_if (agent ...)  ## an example of use can be: search_item_with_id (an_id: INTEGER) -- Moves items cursor if not found is_after local l_found: BOOLEAN do from items.start until items.after or l_found loop l_found := items.item.primary_key = an_id if not l_found then items.forth end end ensure cursor_on_element_if_found: not items.after implies items.item.primary_key = an_id end  • Feb 01 Eiffel: ODBC Dealing with BIGINT ## Eiffel Seems I'm getting an INTEGER_32_REF from a BIGINT from ODBC with Eiffel DB_SELECTION.cursor. Sometimes I seem to have the adecuate value, but sometimes not... 946383958 => good INTEGER_32_REF (id->4 of following table) 9475984837 => 886050245 WRONG INTEGER_32_REF (id->4 of following table) 646383958 => good INTEGER_32_REF (id->3 of following table) 6475984837 => -2113949755 WRONG INTEGER_32_REF (id->4 of following table) ...  It seems to behave like not treating the BIGINT and giving the INTEGER_32_REF value directly interpreted from the DB value, typical case passing over the 2^32 ## Postgresql Having a table with following data as electricity_amount BIGINT NOT NULL DEFAULT 0 id | a_date | amount | electricity_amount | consumption_sector_id | electricity_rate_id ----+------------+-----------+--------------------+-----------------------+--------------------- 1 | 2019-01-01 | 746383958 | 7475984837 | 1 | 1 2 | 2019-02-01 | 846383958 | 8475984837 | 1 | 1 3 | 2019-03-01 | 646383958 | 6475984837 | 1 | 1 4 | 2019-04-01 | 946383958 | 9475984837 | 1 | 1  • Jan 31 Eiffel: non-compatible actual argument in feature call I don't understand why it is so. • If I say attached {G} it works • If I say nothing which would be the expected behavior for me calling_entity: detachable RELATED_DB_ENTITY should be conform (once attached) to G which is -> DB_ENTITY • If I say DB_ENTITY it doesn't • If I say RELATED_DB_ENTITY either does it pass Why do I have to specify {G}??? ## SIT_HANDLER class SIT_HANDLER[G -> DB_ENTITY create default_create, make_from_db_service, make_from_json end] feature -- some_feature do if attached {G} l_rest_request.calling_entity as l_calling_entity then db_service.set_item_prototype (l_calling_entity) -- Complains here!!!!!!!!!!!! db_service.load_with_relationships (l_rest_request) ... end end -- class  ## REST_REQUEST class REST_REQUEST feature -- Access calling_entity: detachable RELATED_DB_ENTITY -- RELATED_DB_ENTITY inherits DB_ENTITY ... end -- class  ## DB_SERVICE class DB_SERVICE [G -> DB_ENTITY create default_create, make_from_db_service, make_from_json end] feature -- Status setting item_prototype: G set_item_prototype (v: like item_prototype) do item_prototype := v ensure item_prototype = v end ... end -- class  • Jan 30 Eiffel: setting a constant with reference to other class constant How to set a constant refering to another class constant in Eiffel? Something like that doesn't compile unfortunately Default_log_level: like {MY_LOGGER}.log_level = {MY_LOGGER}.Log_level_info  • Jan 27 Eiffel: REAL_32.to_double gives a strange value Trying to transform a real_32 to real_64, I'm getting real_32: 61.55 real_64: 61.54999923706055  Am I wrong with the to_double function? • Jan 26 Eiffel: multilines string formating Didn't find a better way to format a multiline string than this way... seems complicated. What would be the best way to format this type of code? l_qry := "SELECT% % * % %FROM % % enumerate % %WHERE % % " + {like item_prototype}.Primary_key_db_column_name + " = " + l_category_id + " % %UNION % % SELECT % % e.* % % FROM % % enumerate e % %INNER JOIN % % enumerates_leaves s ON s." + {like item_prototype}.Primary_key_db_column_name + " = e." + {like item_prototype}.Category_db_column_name + " % %) SELECT * FROM enumerates_leaves WHERE enumerates_leaves." + {like item_prototype}.Category_db_column_name + " IS NOT NULL;"  • Jan 26 eiffel: does the across structure move the cursor of current iterable structure? I was wondering if the across structure uses an own cursor or a separated one? does it ensure that cursor hasn't moved and if so how can it be expressed for other examples? • Jan 25 Eiffel: how to use old keyword in ensure contract clause with detached How to use the old keyword into ensure clause of a feature, the current statement doesn't seem to be valid at runtime relationships: CHAIN -- any chain some_feature do (...) ensure relationship_added: attached relationships as l_rel implies attached old relationships as l_old_rel and then l_rel.count = l_old_rel.count end  ## For the whole case, following screenshots demonstrate the case start of routine execution end of routine execution • Jan 24 Eiffel: void safety, a concise way to test if an object exists and then call its feature I was wondering if there is a clearer statement then if not attached foo then create foo end if attached foo as l_foo then l_foo.bark end  as if not attached foo then create foo foo.bark else foo.bark end  would repeat the foo.bark and obviously I want to avoid it... and even the last statement won't compile with void-safety as foo on else could be void... • Jan 24 Eiffel: a way to ensure db_cursor: DB_RESULT has not moved I'm looking for a way to ensure that cursor: detachable DB_RESULT from DB_SELECTION class hasn't moved. I didn't find any method to get access to it. Does the following statement ensure it?  ensure cursor_not_moved: a_db_service.cursor.is_equal(old a_db_service.cursor)  The item method for example doesn't seem to ensure that even if it is only consulting a value of a given row index • Jan 13 Eiffel: Error: variable is not properly set. in make calling default_create or any parent calling/redefining default_create Not sure exactly, but it makes various time I got a Error: variable is not properly set. in creation procedures' calling order. I figured out that creating class attributes before calling default_create seemed to solve the problem. Why is that so? It doesn't seem that default_create calls something in my make routine??!!! Try to make an example even if I don't think I can reproduce it with a simple example... ## Working class A feature attr: B make do create attr default_create end end  ## Error: variable is not properly set. class A feature attr: B make do default_create create attr end end  • Jan 13 Eiffel: change the signature of a inherited feature How is the correct way to change the signature of a feature in Eiffel if any? if there is no option as I understood, how would be the correct way to define in a parent class that there will be a feature to be able to select but still don't know arguments number and types (types are resolvable with polymorphism...) Is the only available playing with polymorphism having an argument into class a to select of type ANY? ## class SELECTABLE class SELECTABLE select deferred end end -- class  ## class DB_SERVICE class DB_SERVICE inherit SELECTABLE (...) feature -- Status setting select (a_db_connection: DB_CONNECTION) local l_qry: STRING do item := first_item_from_qry (l_qry) end end -- class  • Jan 11 Eiffel: Error: type is based on unknown class Trying to implement some test cases on EWF application with rest web services and JSON objects, I'm gettint a Error: type is based on unknown class. after adding my first class inheriting from EQA_TEST_SET Seems pretty complicated to implement test cases for a simple curl -v --header "Content-Type: application/json" --request POST --data '{"id":11,"name":"someName","enumerate":{"id":5}}' http://localhost:9997/someEntity curl command! How can I do that? Where is there some example? I'm trying to copy-paste the example from $ISE_LIBRARY/contrib/library/web/framework/ewf/wsf/tests/src/test_wsf_request.e as a base, but for the moment....

I can find the class when browsing the dependencies as shown in screenshot, but the compiler not! strange behaviour!

## My app_ewf_app.ecf

<?xml version="1.0" encoding="ISO-8859-1"?>
<system xmlns="http://www.eiffel.com/developers/xml/configuration-1-19-0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.eiffel.com/developers/xml/configuration-1-19-0 http://www.eiffel.com/developers/xml/configuration-1-19-0.xsd" name="sit_ewf_app" uuid="0AB55F0B-014A-4775-B93F-ACC31C9300D5">
<target name="common" abstract="true">
<file_rule>
<exclude>/CVS$</exclude> <exclude>/EIFGENs$</exclude>
<exclude>/\.svn$</exclude> </file_rule> <option warning="true"> <assertions precondition="true" postcondition="true" check="true" invariant="true" loop="true" supplier_precondition="true"/> </option> <capability> <catcall_detection support="none"/> <concurrency support="scoop"/> <void_safety support="all" use="all"/> </capability> <library name="base" location="$ISE_LIBRARY\library\base\base-safe.ecf"/>
<library name="http" location="$ISE_LIBRARY\contrib\library\network\protocol\http\http-safe.ecf"/> <library name="json" location="$ISE_LIBRARY\contrib\library\text\parser\json\library\json.ecf"/>
<library name="lexical" location="$ISE_LIBRARY\contrib\library\gobo\library\lexical\library.ecf"/> <library name="logging" location="$ISE_LIBRARY\library\runtime\logging\logging.ecf"/>
<library name="odbc" location="$ISE_LIBRARY\library\store\dbms\rdbms\odbc\odbc.ecf"/> <library name="store" location="$ISE_LIBRARY\library\store\store.ecf"/>
<library name="time" location="$ISE_LIBRARY\library\time\time.ecf"/> <library name="wsf" location="$ISE_LIBRARY\contrib\library\web\framework\ewf\wsf\wsf-safe.ecf"/>
<library name="wsf_extension" location="$ISE_LIBRARY\contrib\library\web\framework\ewf\wsf\wsf_extension.ecf"/> <cluster name="database" location=".\database\" recursive="true"/> <cluster name="entity" location=".\entity\" recursive="true"/> <cluster name="error" location=".\error\" recursive="true"/> <cluster name="handler" location=".\handler\" recursive="true"/> <cluster name="logger" location=".\logger\" recursive="true"/> <cluster name="misc" location=".\misc\" recursive="true"/> <cluster name="relationship" location=".\relationship\" recursive="true"/> <cluster name="rest" location=".\rest\" recursive="true"/> <cluster name="service" location=".\service\" recursive="true"/> <cluster name="sit-json" location=".\sit-json\" recursive="true"/> <!-- TESTS --> <cluster name="tests" location=".\tests\" recursive="true"/> </target> <target name="ewf_app_any" extends="common"> <root class="EWF_APP" feature="make_and_launch"/> <capability> <concurrency support="scoop"/> </capability> <library name="cgi" location="$ISE_LIBRARY\contrib\library\web\framework\ewf\wsf\connector\cgi-safe.ecf"/>
<library name="libfcgi" location="$ISE_LIBRARY\contrib\library\web\framework\ewf\wsf\connector\libfcgi-safe.ecf"/> <library name="standalone" location="$ISE_LIBRARY\contrib\library\web\framework\ewf\wsf\connector\standalone-safe.ecf"/>
<cluster name="launcher" location=".\launcher\">
<cluster name="any_launcher" location="$|any\"/> </cluster> <cluster name="src" location=".\src\" recursive="true"/> </target> <target name="ewf_app_standalone" extends="common"> <root class="EWF_APP" feature="make_and_launch"/> <capability> <catcall_detection support="none"/> <concurrency support="scoop"/> <void_safety support="all"/> </capability> <variable name="httpd_ssl_disabled" value="true"/> <library name="default_standalone" location="$ISE_LIBRARY\contrib\library\web\framework\ewf\wsf\default\standalone-safe.ecf"/>
<library name="eel" location="$ISE_LIBRARY\contrib\library\text\encryption\eel\eel.ecf"/> <library name="ewsgi" location="$ISE_LIBRARY\contrib\library\web\framework\ewf\ewsgi\ewsgi.ecf"/>
<library name="http_client" location="$ISE_LIBRARY\contrib\library\network\http_client\http_client.ecf"/> <library name="testing" location="$ISE_LIBRARY\library\testing\testing-safe.ecf"/>
<cluster name="launcher" location=".\launcher\">
<cluster name="default_launcher" location="$|default\"/> </cluster> <cluster name="src" location=".\src\" recursive="true"/> </target> <target name="ewf_app_cgi" extends="common"> <root class="EWF_APP" feature="make_and_launch"/> <capability> <concurrency support="scoop" use="none"/> </capability> <library name="default_cgi" location="$ISE_LIBRARY\contrib\library\web\framework\ewf\wsf\default\cgi-safe.ecf"/>
<cluster name="launcher" location=".\launcher\">
<cluster name="default_launcher" location="$|default\"/> </cluster> <cluster name="src" location=".\src\" recursive="true"/> </target> <target name="ewf_app_libfcgi" extends="common"> <root class="EWF_APP" feature="make_and_launch"/> <capability> <concurrency support="scoop" use="none"/> </capability> <library name="default_libfcgi" location="$ISE_LIBRARY\contrib\library\web\framework\ewf\wsf\default\libfcgi-safe.ecf"/>
<cluster name="launcher" location=".\launcher\">
<cluster name="default_launcher" location="\$|default\"/>
</cluster>
<cluster name="src" location=".\src\" recursive="true"/>
</target>
<target name="ewf_app" extends="ewf_app_any">
</target>
</system>


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