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EXTIN'/HPEXTIN This utility procedure is callable by the names EXTIN' and HPEXTIN.
NOTE EXTIN' is provided for compatibility with MPE V. In new program development, it is advisable to call HPEXTIN for ease of use. The declaration is the same for both utility names.
EXTIN'/HPEXTIN converts a byte array containing an input string of ASCII digits into one of these internal representations: * SHORTINT * REAL * INTEGER * LONGREAL See the "Comments" section for more details. Declaration TYPE bytearray = PACKED ARRAY [1..N] OF CHAR; PROCEDURE HPEXTIN ( ANYVAR charstring : bytearray; VAR stringlen : SHORTINT; decplaces : SHORTINT; datatype : SHORTINT; scale : SHORTINT; delimiters : SHORTINT; ANYVAR result : INTEGER; VAR error : SHORTINT ) OPTION UNCHECKABLE_ANYVAR; EXTERNAL; Attributes Parameters charstring = The byte array to be converted, passed (Input): by reference. stringlen = Upon entry, the field width of the ASCII input string including all special characters. (See Comment 1 for more details.) decplaces = The number of digits d to be interpreted as fraction digits (multiply the integer field by 10-d if the input string does not include a decimal point). See Comment 1 for more details. If a decimal point is included in the input string, this parameter has no effect. If decplaces is less than zero, the procedure assumes decplaces is zero. If datatype is 0 or -1, this parameter is ignored. datatype = The internal representation desired: 0 = SHORTINT 1 = REAL -1 = INTEGER -2 = LONGREAL scale = The scale factor (see Comment 2 for more details). This factor is ignored if datatype=0 (SHORTINT) or datatype=-1 (INTEGER). delimiters = Imbedded blanks, dollar signs, and commas in the input are treated differently, depending upon whether the value is even or odd. Even: $ and/or commas and/or imbedded blanks are delimiters. Odd : Imbedded blanks are treated as zeros; a $ and/or a comma to the left of every third digit to the left of the decimal point are allowed. Parameters result= 32-bit pointer (address) to the first (Output): word of result storage according to the type specified. error = Error indicator (see Comments 5 and 6 for more details). 2 = No integer or fraction value was detected (see Comment 6). 1 = An illegal character was detected (see Comment 5). 0 = Valid result; no error. -1 = The number is larger than the largest representable value and an illegal character was detected. -2 = The resulting number is greater than the largest representable value of datatype. See Chapter 1 for details on representable values. -3 = The number is less than the smallest representable value and an illegal character was detected. -4 = The resulting number is less than the smallest representable value of datatype. See Chapter 1 for details on representable values. W = Upon exit, the number of string characters used to compute the result (see Comment 5). Results: See "Parameters (Output)" above. HP FORTRAN 77/XL: Use the $ALIAS directive to call EXTIN' ; use the system intrinsic statement to call HPEXTIN. Errors: See "Parameters (Output)" above. Comments 1. The external form of the input is a string of ASCII digits that can include integer, fraction, and exponent subfields: Integer Fraction Exponent field field field | | | V V V |<---------->| |<----------->| |<---------->| +n...n . n...n E+ee ^ | Decimal point The exponent field input can be any of these forms: +e +ee Ee Eee De Dee -e -ee E+e E+ee D+e D+ee +eee -eee E-e E-ee D-e D-ee where e is an exponent value digit. 2. The scale parameter has no effect if the input string includes an exponent field. Otherwise, a scale of n sets the result to the input string value * 10-n . For example, STRING Array scale RESULT ------------ ----- ------ 4398.76 3 4.39876 543.21 -3 543210. 3. The type of the result is independent of the input string format. For example, the input 4398.76 can be converted to integer form. The conversion rules are stated in Table 3-1. Table 3-1. Rules for Data Type Conversion --------------------------------------------------------------------------------------------- | | | | | Data Type | Value of datatype | Result | | | | | --------------------------------------------------------------------------------------------- | | | | | SHORTINT | 0 | Truncates a fractional input. | | | | | | REAL | 1 | Accepts a fractional input. | | | | | | INTEGER | -1 | Truncates a fractional input. | | | | | | LONGREAL | -2 | Accepts a fractional input. | | | | | --------------------------------------------------------------------------------------------- 4. Leading blanks in the input string are ignored; if the parameter delimiters is odd, trailing blanks are treated as zeros. 5. If error is set to an odd value, an illegal character was input; if error is odd and negative, an illegal character and illegal value was detected. The parameter intlvalue is computed from the input string characters that preceded the delimiting digit or illegal character. Parameter stringlen can be used as an index into charstring to locate that delimiter or illegal character. The following are examples of illegal character inputs: +1.345A (A is illegal) 7543CUP (C, U, and P are illegal) 6. If error is set to 2, no integer or fraction value was detected and a result cannot be computed. The following are examples of non-value inputs: +.E5 (the exponent E5 has no base) -.A (no base, no exponent) 7. When case is significant, the names for the EXTIN'/HPEXTIN procedure are in lower case.
NOTE Dollar signs ($) and commas for monetary or numeration form in the input are ignored, but they must be counted in parameter stringlen, and must be in the proper places (for example, $ must lead a number, and commas should appear every third digit).