Open Watcom FORTRAN 77 Language Reference

More documents

Recommendations

Info

Language Reference 7.2 Character Expressions Character expressions are used to describe computations involving operands of type CHARACTER, the concatenation operator (//) and left and right parentheses. The result of the computation is of type CHARACTER. 7.2.1 Character Operators There is only one character operator, namely the concatenation operator (//). It requires two operands of type CHARACTER. If x is the left operand and y is the right operand, then the result is y concatenated to x. The length of the result is the sum of the lengths of the two operands. For example, the result of ’AAAAA’//’BBB’ is the string AAAAABBB. 7.2.2 Rules for Forming Character Expressions The building blocks for character expressions are called character primaries. They are one of the following. 1. character constant 2. character symbolic constant 3. character variable reference 4. character array element reference 5. character substring reference 6. character function reference 7. ( character expression ) Character expressions are defined as follows: 1. character primary 2. character expression // character primary A character expression is simply a sequence of character primaries, each separated by the concatenation operator (//). Rule 2 implies that character primaries are combined from left to right. Except in a character assignment statement, the operands in a character expression must not contain operands whose length specification is (*) unless the operand is a symbolic constant. Note that, unlike arithmetic expressions, parentheses have no effect on the result of evaluating a character expression. For example, the result of the expressions and ’A’//’B’//’C’ ’A’//(’B’//’C’) is identically the string ABC. 178 Character Expressions
Expressions 7.2.3 Character Constant Expressions A character constant expression is a character expression in which all primaries are one of the following. 1. character constant 2. symbolic character constant 3. ( character constant expression ) As an extension to the FORTRAN 77 language, Open Watcom FORTRAN 77 supports the use of the intrinsic function CHAR in a character constant expression. Example: CHARACTER*6 HELLO, WORLD PARAMETER (HELLO = ’Hello’//CHAR(0)) PARAMETER (WORLD = ’world’//CHAR(7)) PRINT *, HELLO, WORLD END 7.3 Relational Expressions A relational expression is used to compare two arithmetic expressions or two character expressions. It is not possible to compare a character expression to an arithmetic expression. Evaluation of a relational expression produces a result of type logical. 7.3.1 Relational Operators The following table lists the relational operators and the operation they perform. Operator .LT. .LE. .EQ. .NE. .GT. .GE. Relational Operation Less than Less than or equal Equal Not equal Greater than Greater than or equal 7.3.2 Form of a Relational Expression The form of a relational expression is as follows. e1 relop e2 Relational Expressions 179
Page 1 and 2:
Open Watcom FORTRAN 77 Language Ref
Page 3:
Preface Open Watcom FORTRAN 77 is a
Page 6 and 7:
Table of Contents 2.25 ELSE IF Stat
Page 8 and 9:
Table of Contents 3.4.10 Hexadecima
Page 10 and 11:
Table of Contents 11.7 Editing ....
Page 12 and 13:
Table of Contents 12.6.1 ENTRY Stat
Page 14 and 15:
Language Reference 2
Page 16 and 17:
Language Reference 1.3 Source Progr
Page 18 and 19:
Language Reference Example: * From
Page 20 and 21:
Language Reference 8 Order of FORTR
Page 22 and 23:
Language Reference Statement 1 2 3
Page 24 and 25:
Language Reference 2.3 ADMIT Statem
Page 26 and 27:
Language Reference If there is a LO
Page 28 and 29:
Language Reference 2.5 Statement La
Page 30 and 31:
Language Reference 2.6 AT END State
Page 32 and 33:
Language Reference The FORTRAN 77 s
Page 34 and 35:
Language Reference 6. A named block
Page 36 and 37:
Language Reference It is important
Page 38 and 39:
Language Reference 2.11 CHARACTER S
Page 40 and 41:
Language Reference If a symbolic na
Page 42 and 43:
Language Reference Example: LOOP RE
Page 44 and 45:
Language Reference Example: REAL A,
Page 46 and 47:
Language Reference a (d) len is an
Page 48 and 49:
Language Reference 2.15 CONTINUE St
Page 50 and 51:
Language Reference 2.17 DATA Statem
Page 52 and 53:
Language Reference 2. As an extensi
Page 54 and 55:
Language Reference 2.18 DEALLOCATE
Page 56 and 57:
Language Reference 2.19 DIMENSION S
Page 58 and 59:
Language Reference Transfer of cont
Page 60 and 61:
Language Reference Example: * Illeg
Page 62 and 63:
Language Reference c r is a constan
Page 64 and 65:
Language Reference c r is a constan
Page 66 and 67:
Language Reference 2.24 ELSE Statem
Page 68 and 69:
Language Reference 2.26 END Stateme
Page 70 and 71:
Language Reference 2.28 END BLOCK S
Page 72 and 73:
Language Reference 2.30 ENDFILE Sta
Page 74 and 75:
Language Reference 2.31 END GUESS S
Page 76 and 77:
Language Reference 2.33 END LOOP St
Page 78 and 79:
Language Reference 2.35 END SELECT
Page 80 and 81:
Language Reference 2.37 END UNION S
Page 82 and 83:
Language Reference 2.39 ENTRY State
Page 84 and 85:
Language Reference The following ex
Page 86 and 87:
Language Reference 2.42 EXIT Statem
Page 88 and 89:
Language Reference 2.44 FORMAT Stat
Page 90 and 91:
Language Reference 2.45.2 Extended
Page 92 and 93:
Language Reference 2.47 Computed GO
Page 94 and 95:
Language Reference * Illegal use of
Page 96 and 97:
Language Reference 2.50 Arithmetic
Page 98 and 99:
Language Reference An example of an
Page 100 and 101:
Language Reference IF( I .EQ. 10 )T
Page 102 and 103:
Language Reference 2.53.3 IMPLICIT
Page 104 and 105:
Language Reference 2.54 INCLUDE Sta
Page 106 and 107:
Language Reference Example: LOGICAL
Page 108 and 109:
Language Reference It is assigned t
Page 110 and 111:
Language Reference 3. This specifie
Page 112 and 113:
Page 114 and 115:
Language Reference 2.57 INTRINSIC S
Page 116 and 117:
Page 118 and 119:
Language Reference 2.59 LOOP Statem
Page 120 and 121:
Language Reference 2.61 NAMELIST St
Page 122 and 123:
Language Reference Example: &PERSON
Page 124 and 125:
Language Reference FILE = fin fin i
Page 126 and 127:
Language Reference Notes: 1. If the
Page 128 and 129:
Language Reference 2.64 PARAMETER S
Page 130 and 131:
Language Reference 2.66 PRINT State
Page 132 and 133:
Language Reference Example: PRINT 1
Page 134 and 135:
Language Reference 2.68 QUIT Statem
Page 136 and 137:
Language Reference 2. An internal f
Page 138 and 139:
Language Reference Example: READ( 8
Page 140 and 141: Language Reference a (d) len is an
Page 142 and 143: Language Reference 2.71 RECORD Stat
Page 144 and 145: Language Reference 2.73 RETURN Stat
Page 146 and 147: Language Reference Notes: 1. The un
Page 148 and 149: Language Reference PROGRAM MAIN . .
Page 150 and 151: Language Reference Example: SELECT
Page 152 and 153: Language Reference 2.78 STRUCTURE S
Page 154 and 155: Language Reference 2.80 UNION State
Page 156 and 157: Language Reference 2.82 VOLATILE St
Page 158 and 159: Language Reference 2.84 WHILE State
Page 160 and 161: Language Reference REC = rn IOSTAT
Page 162 and 163: Language Reference 150
Page 164 and 165: Language Reference Example: DO10I=1
Page 166 and 167: Language Reference 123.764 .4352344
Page 168 and 169: Language Reference Actually, holler
Page 170 and 171: Language Reference 158 Symbolic Con
Page 172 and 173: Language Reference [lo:] hi where:
Page 174 and 175: Language Reference 4.4 Classifying
Page 176 and 177: Language Reference 4.5 Classifying
Page 178 and 179: Language Reference Example: CHARACT
Page 180 and 181: Language Reference STRUCTURE /PERSO
Page 182 and 183: Language Reference SUBROUTINE PRINT
Page 184 and 185: Language Reference 172 Unions
Page 186 and 187: Language Reference Operator Arithme
Page 188 and 189: Language Reference 7.1.3 Arithmetic
Page 192 and 193: Language Reference where: relop is
Page 194 and 195: Language Reference Note that the op
Page 196 and 197: Language Reference 1. logical term
Page 198 and 199: Language Reference 186 Constant Exp
Page 200 and 201: Language Reference 8.3 Logical Assi
Page 202 and 203: Language Reference 8.6 Extended Ass
Page 204 and 205: Language Reference 192 Extended Ass
Page 206 and 207: Language Reference Examples follow
Page 208 and 209: Language Reference 9.4 DO - END DO
Page 210 and 211: Language Reference The next example
Page 212 and 213: Language Reference where: stmt is a
Page 214 and 215: Language Reference Example: * Illeg
Page 216 and 217: Language Reference - the string -10
Page 218 and 219: Language Reference 9.12 GUESS-ADMIT
Page 220 and 221: Language Reference 9.13 QUIT QUIT [
Page 222 and 223: Language Reference Example: LOOP RE
Page 224 and 225: Language Reference READ statement t
Page 226 and 227: Language Reference 214 Notes on Str
Page 228 and 229: Language Reference 10.3 Records FOR
Page 230 and 231: Language Reference accessed directl
Page 232 and 233: Language Reference Example: WRITE(1
Page 234 and 235: Language Reference 5. Any character
Page 236 and 237: Language Reference 224 Printing of
Page 238 and 239: Language Reference Example: REAL X
Page 240 and 241:
Language Reference 11.6 Nonrepeatab
Page 242 and 243:
Language Reference Example: PRINT
Page 244 and 245:
Language Reference Example: INTEGER
Page 246 and 247:
Language Reference 11.7.10.4 E and
Page 248 and 249:
Language Reference n Example: is 4
Page 250 and 251:
Language Reference and is read into
Page 252 and 253:
Language Reference 3. An input item
Page 254 and 255:
Language Reference 1. Blanks are ne
Page 256 and 257:
Language Reference e is an expressi
Page 258 and 259:
Language Reference Example: * Illeg
Page 260 and 261:
Language Reference 12.3.2 Type Conv
Page 262 and 263:
Language Reference 12.3.7 Type Conv
Page 264 and 265:
Language Reference 12.3.13 Remainde
Page 266 and 267:
Language Reference 12.3.18 Choosing
Page 268 and 269:
Language Reference 12.3.24 Square R
Page 270 and 271:
Language Reference 12.3.28 Sine Def
Page 272 and 273:
Language Reference 12.3.33 Arccosin
Page 274 and 275:
Language Reference 12.3.38 Gamma Fu
Page 276 and 277:
Language Reference 12.3.45 Lexicall
Page 278 and 279:
Language Reference Definition: Name
Page 280 and 281:
Language Reference 12.3.53 Binary P
Page 282 and 283:
Language Reference 12.3.58 Allocate
Page 284 and 285:
Language Reference Example: INTEGER
Page 286 and 287:
Language Reference 2. An array name
Page 288 and 289:
Language Reference 5. A name that a
Page 290 and 291:
Language Reference 12.8.1 Dummy Arg
Page 292 and 293:
Language Reference Example: DIMENSI
Page 294 and 295:
Language Reference 282 Subprogram A
Page 296 and 297:
Appendices 284
Page 298 and 299:
Appendices 10. The DOUBLE COMPLEX s
Page 300 and 301:
Appendices 36. Non-character arrays
Page 303 and 304:
Index AMAX1 253 AMIN0 254 $ AMIN1 2
Page 305 and 306:
Index DATAN 260 dummy procedure 280
Page 307 and 308:
Index AINT 250 ANINT 251 ASIN 259 H
Page 309 and 310:
Index DREAL 249 IAND 264 DSIGN 252
Page 311 and 312:
Index RETURN 32, 46, 56, 121, 132,
show all

Open Watcom FORTRAN 77 Language Reference

Create successful ePaper yourself

Delete template?

Save as template?