290 questions
0
votes
2
answers
56
views
Error: Non-compatible actual argument in a feature call in Eiffel code for reading and writing files
I am working on a program in Eiffel that reads data from an input file, processes it, and writes the results to an output file. The input file contains: ID, name, birthdate, address, and the number of ...
- 1
0
votes
1
answer
67
views
Writing a project in EiffelStudio that simulates a dice roll
I am attempting to simulate a dice roll using the RANDOM class in the BASE library. With my current code, it only ever prints out 5.
class
APPLICATION
create
make
feature
make
...
- 11
1
vote
1
answer
68
views
why here 'or' follows with an 'else', what kind of branches do they make?
I saw a really confusing statement when I read OMOHUNDRO's article about balltree construction algorithms:
--...
if pq.empty or else
btm.bvol <= pq.top.bvol then done:=true
--...
I don't know how ...
- 431
1
vote
1
answer
86
views
How to use convert for creation
Using "Void safety - complete", my code:
class TENSOR_SHAPE
create
default_create,
from_tuple
convert
from_tuple ({TUPLE [INTEGER]})
feature -- Initialization
from_tuple (...
- 23
1
vote
2
answers
115
views
How to print unicode to console in Eiffel?
Evidently in python:
print u'\u0420\u043e\u0441\u0441\u0438\u044f'
outputs:
Россия
How do I do this in Eiffel?
- 23
0
votes
0
answers
98
views
Why does my Cecil / Eiffel code not find the 'apply' procedure in class PROCEDURE?
I want a C routine, which is supplied with an Eiffel 'agent' to call the routine 'apply' in the class PROCEDURE.
int c_nng_aio_set_procedure_target(void *item, EIF_OBJECT target) {
void **pptr = (...
0
votes
2
answers
227
views
Eiffel Studio ARM Apple Silicon M1
I am hoping to create some software with Eiffel & Eiffel Studio
I have a Mac mini with the Apple M1 Arm Processor.
Is there a port of EiffelStudio to native Mac M1?
Does Eiffel Studio support ...
- 41
1
vote
1
answer
86
views
EiffelStudio finalize with contracts enabled
How to produce the Finalized executable with contract checking enabled? It is possible to keep the check statements intact, but can we keep all the pre/postconditions and class invariants?
I need this ...
- 425
1
vote
1
answer
84
views
Implementing a common attribute in recursive data type like TREE
When implementing a recursive data structure like TREE, I need a common attribute per TREE, and I wonder how to implement it:
Adding the attribute to a TREE node, replicates the attribute for every ...
- 4,315
3
votes
3
answers
97
views
Result attached or exception
Let's say that I have a function f which should return an attached T by calling g. However, g returns a detachable T. If g results in a Void, I want to raise an exception like this:
f: T
do
if ...
- 425
1
vote
1
answer
99
views
Exit program in Eiffel
Is there a way in Eiffel to exit a program, possible with a defined exit code like exit in C?
In my case I would like to just end the program like exit(0) would do.
- 425
1
vote
2
answers
90
views
referencing typed element of tuple
Discovering late (used to define classes instead) TUPLES and looking through the documentation I was wondering if there is a mechanism to get the right type of a given TUPLE.
The goal is both ...
- 5,073
0
votes
1
answer
45
views
rescue how to raise further or forget an exception
How do I raise an exception further in eiffel? I have 3 cases
I want to retry
a_feature
local
l_retries_count: INTEGER
do
some_potential_failing_feature
rescue
if ...
- 5,073
1
vote
1
answer
129
views
How to inherit from HASH_TABLE in Eiffel?
I want to make a derived class of HASH_TABLE which implements a few additional features. I tried implementing it like this:
class HASH_TABLE2[G->HASHABLE]
inherit
HASH_TABLE[G,G]
rename
...
- 101
2
votes
2
answers
29
views
how to retreive the value of a custom header into a WSF_REQUEST
I'm looking how to get a custom header value from a received WSF_REQUEST. I read the docs quickly and didn't find the answer.
'Authorization': 'Bearer my_long_token'
- 5,073
1
vote
0
answers
177
views
How to compile using EiffelStudio? VD43 Precompiled file is missing or unreadable (...)/driver.exe - External C compilation failed
After installing EiffelStudio I can't compile and run any project because I always get VD43 warning and C Compiler Error.
2 VD43 Precompiled file is missing or unreadable. File 'c:\users\username\...
- 101
1
vote
1
answer
37
views
How to enable debug into estudio
I tried to enable the debug syntax into estudio without afording it. In this case it is from a library and it doesnt enter into the
debug
io.put_string ("any debug statement here")
end
...
- 5,073
0
votes
1
answer
27
views
Strategy to reuse created DB_SERVICES and other instances into an EWF_APP by thread
Into my EWF_APP[EWF_APP_EXECUTION] the EWF_APP_EXECUTION inherits from WSF_FILTERED_ROUTED_EXECUTION defining setup_router.
To be able to access informations globally by thread (as far as I understand ...
- 5,073
0
votes
0
answers
38
views
how could a check not been done with all assertions set to true?
Running a debug session with estudio with all assertions set to true (I checked into cluster, common target, specific target, etc.) pass over a check assertion?
I also tried to remove EIFGENs and ...
- 5,073
0
votes
1
answer
28
views
where rescue should be called in an EWF_APP to be able to close a database connection
Inheriting from WSF_FILTERED_ROUTER_EXECUTION I redefine the clean to be able to close DB Connections. But when there is an assertion failure, I don't know where to call the clean on a rescue clause. ...
- 5,073
0
votes
2
answers
47
views
READABLE_STRING_GENERAL vs STRING
When to use which type of STRING in eiffel? I saw using READABLE_STRING_GENERAL and having to l_readable_string.out' to convert it to STRING`
- 5,073
0
votes
1
answer
71
views
number of seconds since epoch in eiffel for a DATE_TIME object
how would you calculate the number of seconds since epoch in eiffel for a DATE_TIME object?
What is the proper way to do it with the current libraries?
- 5,073
0
votes
2
answers
42
views
how would you calculate the number of seconds since epoch in eiffel for a DATE_TIME object
how would you calculate the number of seconds since epoch in eiffel for a DATE_TIME object?
- 5,073
0
votes
1
answer
372
views
Understanding Eiffel loop variant/invariant
I was trying to have a structure which talks himself about variants and invariants into Eiffel loops, but don't understand the variant part!
from
l_array := <<1,2,30,60>>
l_index :=...
- 5,073
0
votes
1
answer
45
views
What is the best way to declare a constant into a class that can be redefined
What is in eiffel the best way to have a constant which can be redefined?
class A => color: STRING = "green"
color B inherit A => cannot redefine
while having a function which only ...
- 5,073
0
votes
1
answer
65
views
eiffel: cluster has two classes with the same name
How to deal with cluster has two classes with the same name with eiffel studio?
when I want to choose between 2 versions?
Where can I find documentation about that?
Think that there is a trick with ...
- 5,073
0
votes
1
answer
39
views
eiffel: a statement for explicitly executing code when assertions are on
Sometimes the checks and contract constructions need an elaboration which wants to be avoided when assertions removed to improve performances and avoid doing useless things with the "only" ...
- 5,073
0
votes
1
answer
88
views
How do I get agents to work in {ARRAY}.do_if in Eiffel?
I am trying to iterate an array in Eiffel. And select some elements, using do_if.
What I have tried.
my_method (list:ARRAY[INTEGER])
local
low : ARRAYED_LIST[INTEGER]
piv : INTEGER
...
- 7,715
1
vote
2
answers
54
views
How can I get more information when debugging a contract violation that checks for equality
I have the following Eiffel code. I am doing test-driven-design with contracts.
check
sorter.sorted (<<1>>).is_equal (<<1>>)
end
The code correctly detects that my sort ...
- 7,715
1
vote
1
answer
97
views
eiffel across an_iterable as vs is
I didn't find the documentation about the difference between is and as
I'd like to implement an iterator something similar to this MAP, I'd like to know what TYPE is returned with the is keyword and ...
- 5,073
0
votes
1
answer
40
views
eiffel: type is based on unknown class (even when visible into libraries)
Trying to include a library I just created I'm unable to have the Class available even if it appears into the libraries on the group view of eiffel studio
../thirdparty/moon_time/sunriset_lib.ecf
&...
- 5,073
0
votes
1
answer
43
views
eiffel: semantic of ANY default
Surprised that Default in class ANY is frozen and without implementation???, what is the semantic for this function??
Class ANY
frozen default: detachable like Current
-- Default value of ...
- 5,073
0
votes
2
answers
41
views
eiffel type conformance and attachement check not working
Trying to solve one of the SCOOP consequences with make_from_separate I'm running into an issue where at runtime types seem to be the same and won't pass the attached statement.
non_separate_from_any
...
- 5,073
0
votes
1
answer
29
views
non-compatible actual argument in feature call in collection make_from_separate
Don't understand where I'm wrong here...
class
LINKED_LIST_SEP[G]
inherit
LINKED_LIST [G]
create
make,
make_from_iterable,
make_from_separate
feature {NONE} -- Initialization
...
- 5,073
0
votes
1
answer
20
views
The class inherits two different generic derivations of the same class
What is the proper way of precising the type of an iterable through inheritence.
as inherit FOO[like babar] is not alowed
FOO
class FOO
inherit
ITERABLE[detachable ANY] -- I know garbage but ...
- 5,073
0
votes
0
answers
27
views
non-compatible actual argument in feature call with generic separate arguments. A way to use anchored type?
As far as I understand,
separate does not conform to non separate
non separate conforms to separate
so, that's the reason the compiler complains when I say like Current, when the P and S I ...
- 5,073
0
votes
1
answer
77
views
Is it possible to make a create which returns a boolean
hi i dont know if i asked the question clearly.
i have a deferred class "animal" which contains two features : "bite" (this returns a boolean -> bite:BOOLEAN) and "speak"(speak(word:BOOLEAN)).
now ...
- 332
0
votes
1
answer
43
views
estudio does not check `require` when it should?
Eiffel Studio seems to pass through my requirements even if I have them enabled on project settings. And as far as I remember I was able some time to put a break point into the requirements...
I don'...
- 5,073
0
votes
1
answer
29
views
Two different configuration files share the same UUID. In configuration
Don't understand this message and neither how to fix it under estudio 19.12
Warning code: VD80
Configuration warning
Two different configuration files share the same UUID. In configuration:
/home/...
- 5,073
0
votes
1
answer
66
views
Eiffel avoiding duplicates into ecf file
I have duplicate classes into a used library. How can I specify on the ecf file that I want to exclude a path?
Error code: VD71
Configuration error
Duplicate class: BASIC
/home/pg/data/solarity/sit-...
- 5,073
0
votes
1
answer
57
views
Passing anonymous object of derived class to a routine in Eiffel
Assuming that we have:
class A ...
class B inherit A ...
f (a_a: A) ...
Then, can you write something like the following pseudocode, without using a temporary variable?
-- `y` is an argument to B'...
- 3,016
0
votes
2
answers
72
views
Sharing a type with a generic class?
How do you declare a variable to be the same type as a type parameter used to instantiate a generic class? The following code does not compile:
class
TEST [G, H -> INTEGER]
feature
f (i:...
- 3,016
0
votes
0
answers
155
views
Eiffel failure on OS X - Eiffel cannot find library
I use macOS Catalina, and installed EiffelStudio per instructions on the EiffelStudio install page. When I executed estudio on the command line, I got this error
$ estudio
dyld: Library not loaded: /...
- 253
0
votes
1
answer
62
views
Eiffel separate object into ensure statement
Is there a way to have a separate object to be checked as ensure with the separate obj as l_obj statement?
I guess having a boolean function should work.
Any reason for that I don't understand?
...
- 5,073
1
vote
1
answer
200
views
Error code: VUTA(3) Error: separate target of the Object_call is not controlled
I'm a complete beginner to Eiffel and I'm implementing a linked list as an exercise. I get the following error in the feature has (which tells you if the list contains v).
Error code: VUTA(3)
Error: ...
- 13
0
votes
1
answer
29
views
Implementation contraint: The class feature only_from_type uses an inline agent
Is there a semantic behind not being able to have an agent into a ensure class routine or is it a current compiler restriction?
only_from_type (some_items: CHAIN[like Current]; a_type: detachable ...
- 5,073
0
votes
1
answer
61
views
variable is not properly set after renaming into heir
I know how to fix it (see my solution @bottom) but don't understand why this compilation error occurs, as in my mind, renamed attributes should be created by the Precursor into default_create. Why isn'...
- 5,073
0
votes
1
answer
46
views
How can I run a cursor tree in Eiffel?
I need a cursor tree and I found CURSOR_TREE and RECURSIVE_CURSOR_TREE classes in EiffelStudio but they are deferred and I don't know how to implement them. Isn'it strange?
- 7
1
vote
1
answer
53
views
check with no content at runtime without assertions
As far as I understood in Eiffel, the following code without assertions fails if the statement returns False
check
i_m_alive: i.alive
then
do_nothing
end
Maybe I'm badly using it but ...
- 5,073
0
votes
1
answer
42
views
How to declare an INTEGER_64 from number?
How to declare an INTEGER_64 from a declared number?
("3000000000").to_integer_64
is the only way I found
- 5,073