basic/doc/
chapter_3.rs

1/*!
2# Functions
3
4Functions convert various inputs to an output value. Most functions convert
5a value to a value but some get their input from the operating system.
6For example, `TIME$` gets the local system time. You might be wondering why
7`TIME$` is a function and not a variable. You can use `TIME$()` if you prefer.
8*/
9
10pub mod ABS {
11    /*!
12    ## `ABS(X)` Returns the absolute value of X.
13    ```text
14    PRINT ABS(-0.123)
15     0.123
16    ```
17    */
18}
19
20pub mod ASC {
21    /*!
22    ## `ASC(X$)` Returns the unicode value of the first character of X.
23    ```text
24    PRINT ASC("A")
25     65
26    ```
27    */
28}
29
30pub mod ATN {
31    /*!
32    ## `ATN(X)` Returns the arctangent of X.
33    ```text
34    PRINT ATN(3)
35      1.2490457
36    ```
37    */
38}
39
40pub mod CDBL {
41    /*!
42    ## `CDBL(X)` Returns X as a Double.
43    ```text
44    PRINT 1/CDBL(3)
45      0.3333333333333333
46    ```
47    */
48}
49
50pub mod CHR {
51    /*!
52    ## `CHR$(X)` Returns a character of ASCII X.
53    ```text
54    PRINT CHR$(65)
55    A
56    ```
57    */
58}
59
60pub mod CINT {
61    /*!
62    ## `CINT(X)` Returns X as an Integer. Overflow error may occur.
63    ```text
64    PRINT CINT(-9.9)
65    -10
66    ```
67    */
68}
69
70pub mod COS {
71    /*!
72    ## `COS(X)` Returns the cosine of X in radians.
73    ```text
74    PRINT COS(0.123)
75     0.99244505
76    ```
77    */
78}
79
80pub mod CSNG {
81    /*!
82    ## `CSNG(X)` Returns X as a Single.
83    ```text
84    PRINT 1/CSNG(3#)
85      0.33333334
86    ```
87    */
88}
89
90pub mod DATE {
91    /*!
92    ## `DATE$` Returns the system date.
93    ```text
94    PRINT DATE$
95    12-31-2000
96    ```
97    */
98}
99
100pub mod EXP {
101    /*!
102    ## `EXP(X)` Returns e to the power of X.
103    ```text
104    PRINT EXP(1)
105     2.7182817
106    ```
107    */
108}
109
110pub mod FIX {
111    /*!
112    ## `FIX(X)` Returns the truncated integer value of X.
113    See `INT` for a flooring function.
114    ```text
115    PRINT FIX( 9.9) FIX(-9.9)
116     9  9
117    ```
118    */
119}
120
121pub mod HEX {
122    /*!
123    ## `HEX$(X)` Returns hexadecimal string of integer X.
124    ```text
125    PRINT HEX$(-1)
126    FFFF
127    ```
128    */
129}
130
131pub mod INKEY {
132    /*!
133    ## `INKEY$` Returns a single key press, empty string if none.
134    ```text
135    I$="":WHILE LEN(I$)=0:I$=INKEY$:WEND:PRINT I$
136    ```
137    */
138}
139
140pub mod INSTR {
141    /*!
142    ## `INSTR([I],X$,Y$)` Returns position of Y$ in X$.
143    Optionally, start searching at index I.
144    Returns 0 if not found. Returns I or 1 if Y$ = "".
145    ```text
146    PRINT INSTR("abcdeb","b")
147     2
148    PRINT INSTR(5,"abcdeb","b")
149     6
150    ```
151    */
152}
153
154pub mod INT {
155    /*!
156    ## `INT(X)` Returns the largest integer <= X.
157    See `FIX` for a truncating function.
158    ```text
159    PRINT INT(9.9) INT(-9.9)
160     9 -10
161    ```
162    */
163}
164
165pub mod LEFT {
166    /*!
167    ## `LEFT$(A$,X)` Returns the leftmost X characters of A$.
168    ```text
169    PRINT LEFT$("HUNT THE WUMPUS", 4)
170    HUNT
171    ```
172    */
173}
174
175pub mod LEN {
176    /*!
177    ## `LEN(X$)` Returns the number of characters in X$.
178    ```text
179    PRINT LEN("TO")
180     2
181    ```
182    */
183}
184
185pub mod LOG {
186    /*!
187    ## `LOG(X)` Returns the natural logarithm of X.
188    ```text
189    PRINT LOG(8/37)
190    -1.5314764
191    ```
192    */
193}
194
195pub mod MID {
196    /*!
197    ## `MID$(A$,X,[Y])` Returns a portion of A$.
198    The returned string will begin with the character in position X.
199    If Y is present it will limit the length, otherwise everything
200    until the end of the string is returned.
201    ```text
202    PRINT MID$("HUNT THE WUMPUS", 6, 3)
203    THE
204    PRINT MID$("HUNT THE WUMPUS", 6)
205    THE WUMPUS
206    ```
207    */
208}
209
210pub mod OCT {
211    /*!
212    ## `OCT$(X)` Returns octal string of integer X.
213    ```text
214    PRINT OCT$(-1)
215    177777
216    ```
217    */
218}
219
220pub mod RIGHT {
221    /*!
222    ## `RIGHT$(A$,X)` Returns the rightmost X characters of A$.
223    ```text
224    PRINT RIGHT$("HUNT THE WUMPUS", 6)
225    WUMPUS
226    ```
227    */
228}
229
230pub mod POS {
231    /*!
232    ## `POS(X)` Returns the horizontal cursor position of the terminal.
233    `X` is optional and ignored. First position is 0.
234    ```text
235    PRINT "     ";POS()
236          5
237    ```
238    */
239}
240
241pub mod RND {
242    /*!
243    ## `RND(X)` Returns a pseudo-random number.
244    Wichman-Hill Random Number Generator.
245    Returns a random Single between 0 and 1 when X is missing or > 0.
246    When X is 0, return the previous random number.
247    When X < 0 the random number generator is seeded with X.
248    The `CLEAR`, `NEW` and `RUN` statements reseed the generator with entropy.
249    ```text
250    PRINT RND()
251     0.6923401
252    ```
253    */
254}
255
256pub mod SGN {
257    /*!
258    ## `SGN(X)` Returns the sign of X.
259    Returns -1 if X is negative, 1 if positive, and 0 if zero.
260    ```text
261    PRINT SGN(+1)
262     1
263    ```
264    */
265}
266
267pub mod SIN {
268    /*!
269    ## `SIN(X)` Returns the sine of X in radians.
270    ```text
271    PRINT SIN(0.123)
272     0.1226901
273    ```
274    */
275}
276
277pub mod SPC {
278    /*!
279    ## `SPC(X)` Returns a string of X spaces.
280    ```text
281    PRINT "<"SPC(5)">"
282    <     >
283    ```
284    */
285}
286
287pub mod SQR {
288    /*!
289    ## `SQR(X)` Returns the square root of X.
290    ```text
291    PRINT SQR(5)
292     2.236068
293    ```
294    */
295}
296
297pub mod STR {
298    /*!
299    ## `STR$(X)` Returns the number X as a string.
300    ```text
301    PRINT STR$(-3.14) + "!"
302    -3.14!
303    ```
304    */
305}
306
307pub mod STRING {
308    /*!
309    ## `STRING$(X, <Y|Y$>)` Returns X copies of Y as a string.
310    You can specify Y as an integer or a string. Only the first
311    character of a string is used.
312    ```text
313    PRINT STRING$(5,45)"KAPOW"STRING$(5,"-")
314    -----KAPOW-----
315    ```
316    */
317}
318
319pub mod TAB {
320    /*!
321    ## `TAB(X)` Returns a string of spaces.
322    Used in a `PRINT` statement, moves to the requested column.
323    Does nothing if already past the requested column.
324    If X is negative, moves to the start of next -X wide zone.
325    ```text
326    PRINT 1.99 TAB(20) "furlongs per year"
327     1.99               furlongs per year
328    ```
329    */
330}
331
332pub mod TAN {
333    /*!
334    ## `TAN(X)` Returns the tangent of X in radians.
335    ```text
336    PRINT TAN(5/13)
337     0.40477434
338    ```
339    */
340}
341
342pub mod TIME {
343    /*!
344    ## `TIME$` Returns the system time.
345    ```text
346    PRINT TIME$
347    23:59:59
348    ```
349    */
350}
351
352pub mod VAL {
353    /*!
354    ## `VAL(X$)` Returns a number parsed from string X$.
355    ```text
356    PRINT VAL("1E-2")
357     0.01
358    ```
359    */
360}
basic/doc/chapter_3.rs

basic/doc/
chapter_3.rs
