Bad modemap selected whereas an exact modmap is declared/defined

[Grégory Vanuxem]

Hello,

I am wondering why I have this behavior, see the interpreter session below.

I have a domain JLObjNamedTuple to operate on Julia NamedTuple,
something like a FriCAS Record. It contains two constructors with
declaration signature:
jntuple : String -> %
jntuple : Tuple(Any) -> %

For comparaison, below, 'jobject(String)' has the same
declaration/definition than the first jntuple above:
jobject(str : String) == jlref str

My problem is the function selection of jntuple(String). Here is an
interpreter session:

(1) -> jobject "(a=12,b=13)"

Function Selection for jobject
Arguments: STRING
-> no appropriate jobject found in String
-> no appropriate jobject found in String

Modemaps from Associated Packages
no modemaps

Remaining General Modemaps
[1] Integer -> JLObject from JLObject
[2] String -> JLObject from JLObject
found good modemap for: jobject
String -> JLObject from JLObject

[1] signature: STRING -> JOBJECT
implemented: slot (String) from JOBJECT


(1) (a = 12, b = 13)
Type: JLObject
Time: 0.07 (EV) + 1.69 (OT) = 1.76 sec
(2) -> jntuple "(a=12,b=13)"

Function Selection for jntuple
Arguments: TUPLE(STRING)
-> no appropriate jntuple found in Tuple(String)
-> no appropriate jntuple found in Tuple(String)

Modemaps from Associated Packages
[1] String -> JLObjNamedTuple from JLObjNamedTuple
[2] Tuple(Any) -> JLObjNamedTuple from JLObjNamedTuple
found good modemap for: jntuple
Tuple(Any) -> JLObjNamedTuple from JLObjNamedTuple

[1] signature: TUPLE(ANY) -> JOBNTPL
implemented: slot (Tuple (Any)) from JOBNTPL


Function Selection for map by coercion facility (map)
Arguments: ((STRING -> ANY), LIST(STRING))
Target type: LIST(ANY)
-> no appropriate map found in List(String)
-> no appropriate map found in List(Any)
-> no appropriate map found in Any
-> no appropriate map found in String
-> no appropriate map found in String
-> no appropriate map found in Any

Modemaps from Associated Packages
[1] ((D4 -> D5),List(D4)) -> List(D5) from ListFunctions2(D4,D5)
if D4 has TYPE and D5 has TYPE
found good modemap for: map
((D4 -> D5),List(D4)) -> List(D5) from ListFunctions2(D4,D5)
if D4 has TYPE and D5 has TYPE

[1] signature: ((STRING -> ANY), LIST(STRING)) -> LIST(ANY)
implemented: slot (List (Any))(Mapping (Any) (String))(List
(String)) from LIST2(STRING,ANY)

BoundsError: attempt to access Char at index [2]

>> System error:
Invalid command given to Julia

(2) -> jntuple (a=12,b=13)

Function Selection for equation
Arguments: (VARIABLE(a), PI)
-> no appropriate equation found in Variable(a)
-> no appropriate equation found in PositiveInteger
-> no appropriate equation found in Symbol
-> no appropriate equation found in Integer
-> no appropriate equation found in Variable(a)
-> no appropriate equation found in PositiveInteger
-> no appropriate equation found in Symbol
-> no appropriate equation found in Integer

Modemaps from Associated Packages
no modemaps

Remaining General Modemaps
[1] (Symbol,Segment(D3)) -> SegmentBinding(D3) from SegmentBinding(
D3)
if D3 has TYPE
[2] (Symbol,String) -> QueryEquation from QueryEquation
[3] (D1,D1) -> Equation(D1) from Equation(D1) if D1 has TYPE
found good modemap for: equation
(D1,D1) -> Equation(D1) from Equation(D1) if D1 has TYPE

[1] signature: (POLY(INT), POLY(INT)) -> EQ(POLY(INT))
implemented: slot (Polynomial (Integer))(Polynomial (Integer))
from EQ(POLY(INT))


Function Selection for equation
Arguments: (VARIABLE(b), PI)
-> no appropriate equation found in Variable(b)
-> no appropriate equation found in PositiveInteger
-> no appropriate equation found in Symbol
-> no appropriate equation found in Integer
-> no appropriate equation found in Variable(b)
-> no appropriate equation found in PositiveInteger
-> no appropriate equation found in Symbol
-> no appropriate equation found in Integer

Modemaps from Associated Packages
no modemaps

Remaining General Modemaps
[1] (Symbol,Segment(D3)) -> SegmentBinding(D3) from SegmentBinding(
D3)
if D3 has TYPE
[2] (Symbol,String) -> QueryEquation from QueryEquation
[3] (D1,D1) -> Equation(D1) from Equation(D1) if D1 has TYPE
found good modemap for: equation
(D1,D1) -> Equation(D1) from Equation(D1) if D1 has TYPE

[1] signature: (POLY(INT), POLY(INT)) -> EQ(POLY(INT))
implemented: slot (Polynomial (Integer))(Polynomial (Integer))
from EQ(POLY(INT))


Function Selection for jntuple
Arguments: TUPLE(EQ(POLY(INT)))
-> no appropriate jntuple found in Tuple(Equation(Polynomial(Integer)))
-> no appropriate jntuple found in Tuple(Equation(Polynomial(Integer)))

Modemaps from Associated Packages
[1] String -> JLObjNamedTuple from JLObjNamedTuple
[2] Tuple(Any) -> JLObjNamedTuple from JLObjNamedTuple
found good modemap for: jntuple
Tuple(Any) -> JLObjNamedTuple from JLObjNamedTuple

[1] signature: TUPLE(ANY) -> JOBNTPL
implemented: slot (Tuple (Any)) from JOBNTPL


Function Selection for map by coercion facility (map)
Arguments: ((EQ(POLY(INT)) -> ANY), LIST(EQ(POLY(INT))))
Target type: LIST(ANY)
-> no appropriate map found in List(Equation(Polynomial(Integer)))
-> no appropriate map found in List(Any)
-> no appropriate map found in Any
-> no appropriate map found in Equation(Polynomial(Integer))
-> no appropriate map found in Equation(Polynomial(Integer))
-> no appropriate map found in Any

Modemaps from Associated Packages
[1] ((D4 -> D5),List(D4)) -> List(D5) from ListFunctions2(D4,D5)
if D4 has TYPE and D5 has TYPE
found good modemap for: map
((D4 -> D5),List(D4)) -> List(D5) from ListFunctions2(D4,D5)
if D4 has TYPE and D5 has TYPE

[1] signature: ((EQ(POLY(INT)) -> ANY), LIST(EQ(POLY(INT)))) -> LIST(ANY)
implemented: slot (List (Any))(Mapping (Any) (Equation
(Polynomial (Integer))))(List (Equation (Polynomial (Integer)))) from
LIST2(EQ(POLY(INT)),ANY)


(2) (a = 12, b = 13)
Type: JLObjNamedTuple
Time: 0.01 (IN) + 0.01 (OT) = 0.03 sec
===========================================================

Is this a bug in function selection? In the Modemaps list:

Modemaps from Associated Packages
[1] String -> JLObjNamedTuple from JLObjNamedTuple
[2] Tuple(Any) -> JLObjNamedTuple from JLObjNamedTuple

The first is the good one, no?

I also noticed that the type of the argument is wrongly determined:

(2) -> jntuple "(a=12,b=13)"

Function Selection for jntuple
Arguments: TUPLE(STRING)
-> no appropriate jntuple found in Tuple(String)
-> no appropriate jntuple found in Tuple(String)

If you have any idea...

Greg

[Waldek Hebisch]

On Tue, Feb 03, 2026 at 06:11:52PM +0100, Grégory Vanuxem wrote:
> Hello,
>
> I am wondering why I have this behavior, see the interpreter session below.
>
> I have a domain JLObjNamedTuple to operate on Julia NamedTuple,
> something like a FriCAS Record. It contains two constructors with
> declaration signature:
> jntuple : String -> %
> jntuple : Tuple(Any) -> %
>
> For comparaison, below, 'jobject(String)' has the same
> declaration/definition than the first jntuple above:
> jobject(str : String) == jlref str
>
> My problem is the function selection of jntuple(String). Here is an
> interpreter session:

In some places interpreter recursively looks for all possiblities.
But in many places once interpreter made a choice it sticks to it
even if there is better/working possiblity. I suspect that
what you see is caused by such premature commitment.

Let ma add that design of algebra interface is affected by
interpreter, current signatures a choosen to get reasonable
behaviour from interpeter inference. For example, it would
be natural to make more general matrix categories and such
change seem to work fine for Spad. But interpreter has special
case for current signatures, which doen not work for more
general ones. In a bit different spirit, we do not export
operation like 'nullSpace' over say PID-s, because current
signatures force coercion to field of fractions, which is
what normal users want.

So, plan your signatures having in mind that _not_ exporting
some signature or deliberatly using a differnt name can
guide interpreter to good choice.

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--
Waldek Hebisch

[Grégory Vanuxem]

Ok, thanks for your time. I will comment out this declaration/definition. jobject can still be used for more precise object like (a=3,b=3.2), jntuple (a=3,b=3.2) returns an uniformly typed JLObjNamedTuple: (a=3.0,b=3.2).

Greg

> To view this discussion visit https://groups.google.com/d/msgid/fricas-devel/aYIzbyz6YzMhdKNN%40fricas.org.