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+--- Thread: [DOCUMENTATION] eval CMD (/thread-7373.html)
[DOCUMENTATION] eval CMD - compsystems - 12-05-2016 03:32 PM
Hello hp-prime developer group
I can not find information about the eval command in lower case, please attach it in the user guide or HELP menu
Examples that can help document it.
on HOME MODE the key [eval] put EVAL
'4/2' [ENTER] ->'4/2'
EVAL(Ans) ->2
on CAS MODE the key [eval] put eval
type(set[1,2,3]) ->DOM_LIST
eval(Ans) -> DOM_LIST //OK
Eval does not evaluate constant identifiers, this is correct because it is within the symbolic environment
with EVAL
type(set[1,2,3]) ->DOM_LIST
EVAL(Ans) -> 7 //OK
or
EVAL(DOM_LIST) -> 7
eval(DOM_LIST) -> DOM_LIST
RE: Undocumented eval CMD - Tim Wessman - 12-05-2016 08:45 PM
Code:
enum gen_unary_types {
// immediate type (without mem allocation) should be < _ZINT
_INT_= 0, // int val
_DOUBLE_= 1, // double _DOUBLE_val
// all type below or equal to _DOUBLE_ must be non pointers
_ZINT= 2, // mpz_t * _ZINTptr
_REAL= 3, // mpf_t * _REALptr
// all type strictly below _CPLX must be real types
_CPLX= 4, // gen * _CPLXptr
_POLY= 5, // polynome * _POLYptr
_IDNT= 6, // identificateur * _IDNTptr
_VECT= 7, // vecteur * _VECTptr
_SYMB= 8, // symbolic * _SYMBptr
_SPOL1= 9, // sparse_poly1 * _SPOL1ptr
_FRAC= 10, // fraction * _FRACptr
_EXT= 11, // gen * _EXTptr
_STRNG= 12, // string * _STRNGptr
_FUNC= 13, // unary_fonction_ptr * _FUNCptr
_ROOT= 14, // real_complex_rootof *_ROOTptr
_MOD= 15, // gen * _MODptr
_USER= 16, // gen_user * _USERptr
_MAP=17, // map<gen.gen> * _MAPptr
_EQW=18, // eqwdata * _EQWptr
_GROB=19, // grob * _GROBptr
_POINTER_=20, // void * _POINTER_val
_FLOAT_=21 // immediate, _FLOAT_val
} ;You can take a look at the CAS source yourself and see exactly what is happening.
Home simply evaluates everything down as far as it can go. The CAS has special handling to keep those special values like DOM_LIST as strings.
Is there anything you are trying to say with this post?
RE: Undocumented eval CMD - Han - 12-05-2016 09:27 PM
Keep in mind that EVAL and eval are two separate commands. Most commands have only one form (uppercase). When a command exhibits different behavior when used as COMMAND vs. command, then this is often due to there being two different versions of the command (one for CAS and one for non-CAS).
Unfortunately, the CAS view (in Textbook mode) seems to always display a command in uppercase (even when not typed in uppercase) which suggests that the two forms are the same when in fact they are not.