HP 3000 Manuals HP 3000 Manuals
Constant Types
Table 3-8. Constant Types
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| SPL | HP C/XL Equivalent |
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| Numeric | Numeric |
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| String | String literal |
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| One-byte string | Character |
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SPL has two types of constants: numeric and string. You may have to
specify the type of the constant with a modifier to avoid errors when
mixing types.
HP C/XL has four types of constants: integer, floating point, character,
and enumeration. Type mixing is generally allowed in HP C/XL, so you do
not need to specify types except when you want to control word size.
NOTE HP C/XL does not permit a leading unary "+" sign, only a unary "-"
sign.
Integer Constants
Table 3-9. Integer Constants
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| SPL | HP C/XL Equivalent |
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| Type: INTEGER | Type: short int |
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| integer-constant: | integer-constant: |
| | |
| [sign] integer | [-] integer |
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Double Integer Constants
Table 3-10. Double Integer Constants
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| SPL | HP C/XL Equivalent |
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| Type: DOUBLE | Type: long int or int |
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| double-integer-constant: | long-integer-constant: |
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| [sign] integer D | [-] integer [L] |
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In HP C/XL, the L (specifying long int) is optional, since int and long
int are equivalent and occupy 32 bits. The L may be lowercase.
Based Constants
Table 3-11. Based Constants
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| SPL | HP C/XL Equivalent |
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| Type: INTEGER | Type: short int |
| DOUBLE | long int or int |
| LOGICAL | unsigned short int |
| BYTE | unsigned char OR unsigned short |
| | int |
| REAL | float |
| LONG | double |
| | |
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| based-constant: | integer-constant: |
| | |
| [sign] % [( base )] value [type] | [-] 0octal-digits [L] |
| | |
| | [-] 0Xhex-digits [L] |
| type: | |
| is D, E, or L (for DOUBLE, REAL, or | Only octal and hexadecimal bases may be |
| LONG); default is single word, usable as | specified. Numbers are signed decimal by |
| INTEGER, LOGICAL, or BYTE. | default. The leading character is a zero. |
| | A trailing L forces a long int constant. |
| | The L and X may be lowercase. |
| | |
| | Floating point cannot be specified |
| | directly. |
| | |
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| Example: | Example: |
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| %170033 octal | 0170033 octal |
| %(16)F01B D hexadecimal | 0xF01B L hexadecimal |
| %(2)11011011 binary | (No equivalent)) |
| | |
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Since HP C/XL can represent only octal, decimal, and hexadecimal values,
based constants must be converted into one of those forms.
CAUTION Since MPE XL floating-point format is different from MPE V
floating point, REAL and LONG based constants must be carefully
translated if they are intended for arithmetic use.
Composite Constants
Table 3-12. Composite Constants
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| SPL | HP C/XL Equivalent |
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| Type: INTEGER | Type: short int |
| DOUBLE | long int or int |
| LOGICAL | unsigned short int |
| BYTE | unsigned char OR unsigned short |
| | int |
| REAL | float |
| LONG | double |
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| composite-constant: | No direct equivalent. |
| | |
| [sign] "["length"/"value[,...]"]" | See "Based Constants" above. |
| [type] | |
| | |
| | |
| type | |
| is D, E, or L (for DOUBLE, REAL, or | |
| LONG); default is single word usable as | |
| INTEGER, LOGICAL, or BYTE. | |
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| Example: | Example: |
| | |
| +[3/2,12/%5252] (= %25252) | 025252 octal |
| -[3/2,12/%5252] (= %152526) | -025252 octal |
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CAUTION Since MPE XL floating-point format is different from MPE V
floating point, REAL and LONG composite constants must be
carefully translated if they are intended for arithmetic use.
Equated Integers
Table 3-13. Equated Integer Constants
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| SPL | HP C/XL Equivalent |
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| equated-integer: | defined-constant: |
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| [sign] identifier [D] | [-] identifier |
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| identifier | identifier |
| is assigned a numeric value in an EQUATE | is assigned a literal value in a #define |
| declaration. It represents a 16-bit | directive. The literal is inserted at |
| INTEGER value. | the reference point. |
| | |
| If D is specified, the value is extended on | Note that, while SPL evaluates an equated |
| the left with zeros to a 32-bit DOUBLE | integer when it is declared, HP C/XL |
| value. | evaluates the literal when the reference is |
| | compiled. |
| | |
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See "EQUATE Declaration and Reference".
Real Constants
Table 3-14. Real Constants
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| SPL | HP C/XL Equivalent |
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| Type: REAL | Type: float |
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| real-constant: | real-constant: |
| 1. [sign] fixed-point-number [E power] | 1. [-] fixed-point-number [E power] |
| 2. [sign] decimal-integer E power | 2. [-] decimal-integer E power |
| 3. [sign] based|composite-integer E | 3. (No equivalent; convert to 1 or 2.) |
| | The E may be in lowercase. |
| | |
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CAUTION Since MPE XL floating-point format is different from MPE V
floating point, REAL based and composite constants must be
carefully translated if they are intended for arithmetic use.
Long Constants
Table 3-15.
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| SPL | HP C/XL Equivalent |
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| Type: LONG | Type: double |
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| long-constant: | real-constant: |
| 1. [sign] fixed-point-number L power | 1. [-] fixed-point-number [E power]; |
| 2. [sign] decimal-integer L power | 2. [-] decimal-integer E power |
| 3. [sign] based|composite-integer L | 3. (No equivalent; convert to 1 or 2.) |
| | The E may be in lowercase. |
| | |
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HP C/XL uses the same representation for float and double constants.
CAUTION Since MPE XL floating-point format is different from MPE V
floating point, LONG based and composite constants must be
carefully translated if they are intended for arithmetic use.
Logical Constants
Table 3-16. Logical Constants
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| SPL | HP C/XL Equivalent |
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| Type: LOGICAL | Type: unsigned short int |
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| TRUE (logical value: 65535; integer value: | No direct equivalent. May be specified |
| -1) | with |
| | |
| | #define TRUE 1 |
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| FALSE (zero) | No direct equivalent. May be specified |
| | with |
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| | #define FALSE 0 |
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| INTEGER, LOGICAL, or BYTE constant: | Any numeric constant (including char): |
| | |
| * true if bit 15 is on (value is odd) | * true if value is nonzero. |
| * false if bit 15 is off (value is even) | * false if value is zero. |
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String Constants
Table 3-17. String Constants
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| SPL | HP C/XL Equivalent |
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| Type: BYTE | Type: string literal OR unsigned char |
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| string-constant: | string-literal: |
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| "characters" | "characters" |
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| characters | characters |
| is one or more ASCII characters (up to | is zero or more ASCII characters. A |
| 127). A quotation mark (""") within | quotation mark, """, within characters is |
| characters is doubled. | represented by the "escape sequence" |
| | "\"", an apostrophe, "'", by "\'", and a |
| | backslash, "\", by "\\". |
| | |
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| For example, the string | For example, the string |
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| He said, "Hi." | He said, "Hi." |
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| is entered as: | is entered as: |
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| "He said, ""Hi.""" | "He said, \"Hi.\"" |
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| Characters are stored two to the 16-bit | Characters are stored as a series of 8-bit |
| word, left justified. | bytes. The string literal is terminated by |
| | HP C/XL with the ASCII NUL character ('\0', |
| | numeric value 0). This fact is used by |
| | many HP C/XL string manipulation functions |
| | that might be used to emulate SPL string |
| | operations. |
| | |
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HP C/XL also has a character constant, in the form:
'char'
where char is a single character, or a special escape sequence using a
leading "\" character, such as those shown above. Escape sequences can
be used in character and string constants to represent any of the 256
ASCII character codes. Consult the HP C Reference Manual for further
details.