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estack_to_short |
Function (ROM Call 0x2C7) |
Converts entry on the expression stack to signed short integer.
estack_to_short converts an entry on the expression stack pointed to by
ptr (it needs to point to the entry tag) to a signed short integer
and stores the result in the location pointed to by value_ptr.
Note that the entry need not be represented by POSINT_TAG
or NEGINT_TAG: it also may be represented by
FLOAT_TAG for example, but the value itself needs to be a whole
number. This function does not remove the entry from the stack.
estack_to_short returns 1 if the conversion was successful, 0 in the case of overflow
(in this case the stored result will be -32768 or 32767 depending of the direction
of the overflow), and -1 if the entry can not be represented as a whole number (in
this case the result is undefined).
Uses: estack_to_float, is_whole_number, is0, _bcd_math
Used by: GetValue, cmd_output, push_ans_entry, push_sq_matrix_to_whole_number