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extended list of types involved in an expression
shape(E: LIST): LIST (of TYPE)
shape(E: RECORD): RECORD (of TYPE)
shape(E:OTHER): TYPE
where OTHER stands for a type which is not LIST, MAT, or RECORD.
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This function returns the extended list of types involved in the
expression E as outlined below:
type(E) = LIST
In this case, Shape(E) is the list whose i-th component is the type
of the i-th component of E.
type(E) = MAT
In this case, Shape(E) is a matrix with (i,j)-th entry equal to the
type of the (i,j)-th entry of E.
type(E) = RECORD
In this case, Shape(E) is a record whose fields are the types of the
fields of E.
Otherwise,
Shape(E)
is the type of E.
/**/ Use R ::= QQ[x];
/**/ L := [1,[1,"a"], x^2-x];
/**/ shape(L);
[INT, [INT, STRING], POLY]
/**/ R := record[name := "test", contents := L];
/**/ shape(R);
record[contents := [INT, [INT, STRING], POLY], name := STRING]
/**/ It.name;
STRING
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There are undocumented functions,
IsSubShape
and
IsSubShapeOfSome
,
for determining if the
shape
of a CoCoA expression is a
subshape
of another. To see the code for these functions, enter
Describe Function("$misc.IsSubShape");
Describe Function("$misc.IsSubShapeOfSome");