SmallBASIC supports the following operators, sorted by priority:
These operators are replaced by the compiler with a command or an expression.
The ++ and -- operators are used to
@@ -1658,7 +1665,7 @@
WINDOW(x1,x2,y2,y1). WINDOW allows you to
redefine the corners of the display screen as a pair of “world”
coordinates. The coordinates of the upper-left corner of the screen is
-given by [x1, y1], the lower-left corner by [x2, y2].The world space
+given by [x1, y1], the lower-left corner by [x2, y2]. The world space
defined by WINDOW is disabled by a WINDOW command without
parameters.
VIEW(x1,y1,x2,y2) defines a viewport with starting point
@@ -1677,6 +1684,127 @@
For more information about graphics commands please see Graphics.
+SmallBASIC supports various commands to read and write a file. Best
+suited for beginners are PRINT and INPUT.
+PRINT writes to a file in the same way as described in the
+section “Print on Screen”. INPUT without additional
+parameters reads one line from a file. To read or write a file, the file
+needs first to be opened. This is done using the command
+OPEN:
OPEN file for INPUT|OUTPUT|APPEND as #1Using the command OPEN, a file with the file name
+file can be opened for reading (INPUT), for
+writing (OUTPUT), and writing to an existing file
+(APPEND). If you use the parameter OUTPUT and
+the file already exist, the file will be deleted. #1 is a
+ID number you can chose freely, but it must start with
+#
To write to a file, PRINT can be used:
PRINT #1, "Hello world"PRINT has the same syntax as the print command in
+section “Print on Screen”. To tell PRINT, that the output
+should be written to a file, use the file ID number as the first
+parameter.
With INPUT, data can be read from a file:
INPUT #1, sINPUT without additional parameters reads a line from
+file with the file ID #1 into the variable
+s.
IF EOF(1) THEN PRINT "End of file reached"EOF(FileID) returns 1 if the end of the
+file is reached and no more data can be read from file. Please note,
+that in case of EOF the File ID is given without
+#.
To close a file, use CLOSE #1.
The following example writes the numbers 1 to 10 to a file and reads +these numbers from a file and prints them on screen.
+' create a text file
+OPEN "MyDemoFile.txt" FOR OUTPUT AS #1
+
+FOR i = 1 TO 10
+ PRINT #1, i
+NEXT
+
+CLOSE #1
+
+' open text file and print content line by line
+OPEN "MyDemoFile.txt" FOR INPUT AS #1
+
+WHILE(!EOF(1)) ' eof works only without #
+ INPUT #1, c
+ PRINT c
+WEND
+
+CLOSE #1TLOAD and TSAVE provide a simple way to
+store arrays, maps or strings in a file and read them. Using a map, json
+data can be created and written to a file.
' Create an array with some data
+A << 1
+A << "test"
+A << 2
+PRINT A ' Output: [1,test,2]
+
+' Save the array. This will create the file myfile.txt in
+' the same directory as your BASIC file
+TSAVE "myfile.txt", A
+
+' Load the file
+TLOAD "myfile.txt", B
+PRINT B ' Output: [1,test,2,]With READ and WRITE numbers, strings and
+arrays can be read and written. The resulting file is a binary file.
+Viewing this file in a text editor will not show you anymore the context
+in a human readable form.
a = 12.3
+b = "test"
+c = [1,2,3,4]
+
+' Write variables to file
+OPEN "text.bin" FOR OUTPUT AS #1
+WRITE #1, a, b, c
+CLOSE #1
+
+' Read variables from file
+OPEN "text.bin" FOR INPUT AS #1
+READ #1, a, b, c
+CLOSE #1
+
+PRINT a
+PRINT b
+PRINT cBGETC and BPUTC can be used to read and
+write a byte from/to a binary file.
' create a binary file
+OPEN "BinaryFile.txt" for output as #1
+
+FOR c = 0 TO 255
+ BPUTC #1, c
+NEXT
+
+CLOSE #1
+
+' open binary file and print content
+OPEN "BinaryFile.txt" FOR INPUT AS #1
+
+FOR i = 0 TO 255
+ c = BGETC(1)
+ PRINT CHR(c);
+NEXT
+
+CLOSE #1The OPTION command is used to pass parameters to the
SB-environment. There are two styles for that, the run-time which can
@@ -1692,10 +1820,10 @@
Use OPTION BASE 1 to set the index of the first element
of an array to 1. This option is useful especially for
beginners, because it makes counting elements more intuitive.
OPTION BASE 1
-A = [1,2,3]
-PRINT A[1] ' Output 1OPTION BASE 1
+A = [1,2,3]
+PRINT A[1] ' Output 1OPTION BASE is a run-time option.
OPTION MATCH [PCRE [CASELESS]|SIMPLE] sets the default
@@ -1736,30 +1864,30 @@
:, and on DOS/Windows by ;#!/usr/local/bin/sbasic
-#inc:"mylib.bas"
-#unit-path: C:\sbasic\units;C:\temp#!/usr/local/bin/sbasic
+#inc:"mylib.bas"
+#unit-path: C:\sbasic\units;C:\tempException handling is supported for file handling, and accessing serial ports and network sockets. Exception handling is typically used with errors raised when calling a file system command that cannot be completed, for example attempting to open a non-existent file.
-TRY
- ' do something
-CATCH err
- print err
- ' do something
-END TRYTRY
- ' do something
-CATCH "Error 1"
- ' do something
-CATCH "Error 2"
- ' do something
-END TRYTRY
+ ' do something
+CATCH err
+ print err
+ ' do something
+END TRYTRY
+ ' do something
+CATCH "Error 1"
+ ' do something
+CATCH "Error 2"
+ ' do something
+END TRYThe TRY statement introduces a try/catch block. A
try/catch block consist of the following structure:
TRY