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ddharing
Aug 22, 2007
This is a feature update to Carl's port of Tiny Basic. There is also a version for Run Basic which is posted in the Run Basic wikispace.
The main purpose of this release was to add enough features to Tiny Basic to run the Sieve benchmark. Here are the new features:
I will post results of the Sieve benchmark test in the Liberty Basic forum and on my blog. Needless to say that Tiny Basic is a lot slower than Run Basic or Liberty Basic. Regardless, it has a lot of potential as an embedded interpreter in a Run Basic or Liberty Basic application. Best of all, it's fun to play with!
Enjoy!
David den Haring.
Simple Computing Blog
The main purpose of this release was to add enough features to Tiny Basic to run the Sieve benchmark. Here are the new features:
- Added seconds and ms functions for benchmarking purposes. In Run Basic, however, if you use the seconds function, it will still display milliseconds. Try "print seconds".
- Added one array to the interpreter environment. In addition to the numeric variables "a" through "z", there is also the numeric array "a(1)" through "a(7001). There is an existing bug in the range checking which will be fixed later. Range checking works for assignment, but not for printing.
- For LB4 only, LOAD, SAVE and AutoRun are fixed. I also added KILL and DIR commands for file management. For the Run Basic release, this code is just commented out.
I will post results of the Sieve benchmark test in the Liberty Basic forum and on my blog. Needless to say that Tiny Basic is a lot slower than Run Basic or Liberty Basic. Regardless, it has a lot of potential as an embedded interpreter in a Run Basic or Liberty Basic application. Best of all, it's fun to play with!
Enjoy!
David den Haring.
Simple Computing Blog
'TinyBasic.bas
' tinyBasic v1.1 - A very small and simple BASIC interpreter written in
' Run BASIC. WARNING: For uber geeks only. :-p
' Copyleft 2005 by Laurent DUVEAU
' http://www.aldweb.com/
' an iziBasic sample program
' Ported to Run BASIC by Carl Gundel and Scott McLaughlin
' http://www.libertybasic.com
' Version 1.1 (Will run on Liberty Basic 4.03 and Run Basic 2.27)
' by David den Haring (8/15/2007)
' The purpose of this release is to add enough features to Tiny Basic in order to run the Sieve benchmark.
' Added a fixed array accessible from the interpreter (i.e. a() )
' Added the functions "seconds" and "ms" or "milliseconds" for benchmarking purposes
' (LB4) Fixed LOAD and SAVE commands because it's tiring to have to type in the Sieve program by hand all the time. I'm having flashbacks to my VIC-20 before the Datasette (i.e. cassette tape storage)
' (LB4) Added DIR and KILL commands for file management. DIR has no parameters. KILL works like LOAD and SAVE.
' (LB4) Fixed AutoRun feature. If file tinyBas0 exists, it will be loaded and run automatically when the interpreter starts.
' A temp
' B temp
' C character index in line
' E line number for error msg
' I temp (loops)
' L number of lines. Index into A$ array
' N number
' S expression stack index
' T temp
' V variable index
' A$ temp
' B$ temp
' C$ character
' D$ single statement
' E$ error message
' G$ string code (")
' H$ HALT code (Line Feed)
' I$-R$ Help
' Z$=A$(26) statement input
DIM A$(125) ' [27-125] = 99 program lines
DIM A(82) ' [27-52] = 26 variables
' [53-82] = 30 items math stack
ArraySize = 7001 'Size of user array
DIM Array(ArraySize) 'Fixed-sized array available to user program
DIM info$(10, 10)
A$(9)="BYE, CLEAR, CLS, END"
A$(10)="HELP, MEM, NEW, RUN, DIR"
A$(11)="GOTO | LOAD | SAVE | KILL <exp>"
A$(12)="IF <exp> THEN <statement>"
A$(13)="INPUT <var>"
A$(14)="[LET] <var>=<exp>"
A$(15)="LIST [<exp>|PAUSE]"
A$(16)="PRINT <exp|str>[,<exp|str>][;]"
A$(17)="REM <any>"
A$(18)=&quA$(18)="Numeric variables available from 'a' to 'z'"
A$(19)="One array variable available -- a(1) to a("; STR$(ArraySize); ")"
A$(20)="No file access for Run Basic yet!"
A$(21)="Functions available: seconds, milliseconds or ms"
TRUE = 1
FALSE = 0
arrayFlag = FALSE 'this flag indicates whether a variable is an array reference or not
simpleFlag = FALSE 'this flag indicates a simple variable on the left side of an expression
'BEGIN
G$=CHR$(34) : H$=CHR$(10) 'double quote and linefeed, respectively
'if the file "tinyBas0" exists, load and run it automatically
B = fileExists(DefaultDir$, "tinyBas0")
IF B = TRUE THEN
Z$="LOAD 0: RUN"
GOTO [AutoRun]
END IF
PRINT "Tiny BASIC v1.1 for Run BASIC and Liberty BASIC"
PRINT "Type HELP for commands."
[Ready] 'display any errors and show ready prompt
simpleFlag = FALSE
arrayFlag = FALSE
IF E$<>"" THEN 'print the error
IF E>0 THEN
E$="#Err in "+STR$(E)+": "+E$
ELSE
E$="#Err: "+E$
END IF
PRINT E$ : E$=""
END IF
PRINT "Ready"
[Input] 'get user input
LINE INPUT Z$
[AutoRun] 'parse the user input
A$(26)=Z$
L=26 : C=1 : GOSUB [GetNumber] : E=N
IF N=0 THEN 'no line number
IF C$="" THEN [Ready] 'user just hit the return key
GOTO [NextStatement] 'get the next token
ELSE 'line number
GOSUB [EnterLine] 'enter line of code into program
IF E$<>"" THEN [Ready] 'branch and display error
GOTO [Input] 'get user input
END IF
[Exec] 'get the next number
GOSUB [GetNumber] : E=N
[NextStatement]
'This commented-out code is for stopping the execution of a running program
'A$=INKEY$
'IF A$=H$ THEN
' A$="Break in "+STR$(E,0)
' PRINT A$ : GOTO [Ready]
'END IF
GOSUB [GetLabel]
IF E$<>"" THEN [Ready] 'branch and display error
SELECT CASE D$
CASE "if"
GOSUB [GetExpression]
IF E$<>"" THEN [Ready]
IF N<1 THEN
B$=A$(L) : C=LEN(B$)+1
GOTO [FinishStatement]
END IF
GOSUB [GetLabel]
IF E$<>"" THEN [Ready]
IF D$<>"then" THEN
E$="'THEN' expected"
GOTO [Ready]
END IF
GOTO [NextStatement]
CASE "rem"
B$=A$(L) : C=LEN(B$)+1
GOTO [FinishStatement]
CASE "input"
GOSUB [GetVar]
IF E$<>"" THEN [Ready]
INPUT N
IF arrayFlag THEN
Array(V)=N 'set the value of the array
ELSE
A(V)=N 'set the value of simple variable
END IF
GOTO [FinishStatement]
CASE "print"
[Print]
GOSUB [SkipSpace]
GOSUB [GetChar]
IF C$=G$ THEN 'print quoted string
B$=""
[NextChar]
C = C + 1 : C$=MID$(A$,C,1)
IF C$="" THEN
E$="Unterminated string"
GOTO [Ready]
ELSE
IF C$<>G$ THEN
B$=B$+C$
GOTO [NextChar]
END IF
END IF
C = C + 1 : C$=MID$(A$,C,1)
IF C$=G$ THEN
B$=B$+C$
GOTO [NextChar]
END IF
PRINT B$;
ELSE 'print expression
GOSUB [GetExpression]
IF E$<>"" THEN [Ready]
B=0
IF B=N THEN 'if variable is 0, then print a trailing "*"
PRINT N;"*";
ELSE
PRINT N;
END IF
END IF
GOSUB [SkipSpace]
GOSUB [GetChar]
IF C$="," THEN C = C + 1 : GOTO [Print]
GOSUB [SkipSpace]
GOSUB [GetChar]
IF C$<>";" THEN
ELSE
C = C + 1
END IF
GOTO [FinishStatement]
CASE "clear"
FOR I=27 TO 52 : A(I)=0 : NEXT I 'clear variables a -- z
FOR I = 0 TO ArraySize : Array(I) = 0: NEXT I 'clear the array -- can't REDIM becuase Run Basic doesn't support it yet
GOTO [FinishStatement]
CASE "run"
FOR I=27 TO 52 : A(I)=0 : NEXT I
L=27 : C=1
GOTO [FinishStatement2]
CASE "goto"
GOSUB [GetExpression]
IF E$<>"" THEN [Ready]
IF E>=N THEN L=27
C=1 : T=N
[NextGoto]
IF L=126 THEN
E$="Line not found"
GOTO [Ready]
END IF
GOSUB [GetNumber]
IF N=T THEN E=N : GOTO [NextStatement]
L = L + 1 : C=1
GOTO [NextGoto]
CASE "new"
FOR I=27 TO 125 : A$(I)="" : NEXT I 'clear the program
FOR I=27 TO 52 : A(I)=0 : NEXT I 'clear variables a -- z
FOR I = 0 TO ArraySize : Array(I) = 0: NEXT I 'clear the array -- can't REDIM becuase Run Basic doesn't support it yet
IF E=0 THEN [FinishStatement]
GOTO [Ready]
CASE "cls"
CLS : GOTO [FinishStatement]
CASE "help"
FOR I=9 TO 21
B$=A$(I) : PRINT B$
NEXT I
GOTO [FinishStatement]
CASE "mem"
B=126
FOR I=27 TO 125
diffI = 152 - I 'Cheating here
B$=A$(diffI) : IF B$="" THEN B=diffI
NEXT I
B=126-B : PRINT B;"*";
PRINT " lines free"
GOTO [FinishStatement]
CASE "end"
GOTO [Ready]
CASE "bye"
GOTO [ExitTinyBAS]
CASE "list"
GOSUB [GetNumber] : T=N : A=L : I=C
IF T=0 THEN
GOSUB [GetLabel]
IF E$="" AND D$="pause" THEN I=C
E$=""
END IF
FOR L=27 TO 125
C=1 : GOSUB [GetNumber]
B=(T=0) OR (N=T)
IF B=TRUE THEN
IF A$<>"" THEN
PRINT A$
IF D$="pause" THEN
B = (L-26) mod 10
IF B=0 THEN PRINT "Pause..."; : INPUT AAA$
END IF
END IF
END IF
NEXT L
L=A : C=I
GOTO [FinishStatement]
CASE "save" 'save a program file
GOSUB [GetExpression]
IF E$<>"" THEN [Ready]
A$="tinyBas"+STR$(N) : A=FALSE
OPEN A$ FOR OUTPUT AS #1
FOR I=27 TO 125
B$=A$(I)
IF B$<>"" THEN PRINT #1,B$ : A=TRUE
NEXT I
CLOSE #1
IF A=FALSE THEN KILL A$
GOTO [FinishStatement]
CASE "load" 'load a program file, but does not account for a program on disk that's too large!
GOSUB [GetExpression]
IF E$<>"" THEN GOTO [Ready]
A$="tinyBas"+STR$(N)
B=fileExists(DefaultDir$, A$)
IF B=FALSE THEN
E$="File "+A$+" not found"
GOTO [Ready]
END IF
OPEN A$ FOR INPUT AS #1
B=FALSE : I=27
B=EOF(#1)
WHILE B <> (-1)
LINE INPUT #1,B$ : A$(I)=B$ : I=I+1
B=EOF(#1)
WEND
CLOSE #1
WHILE I<=125
A$(I)="" : I=I+1
WEND
IF E=0 THEN [FinishStatement]
GOTO [Ready]
CASE "kill" 'delete a program file
GOSUB [GetExpression]
IF E$<>"" THEN [Ready]
A$="tinyBas"+STR$(N)
Kill A$
GOTO [FinishStatement]
CASE "dir" 'list all program files
FILES DefaultDir$, "tinyBas*", info$()
IF VAL(info$(0,0)) > 0 THEN 'list the files
FOR I = 1 to VAL(info$(0,0))
print info$(I, 0), info$(I, 2) 'print filename and date/times stamp
NEXT I
ELSE
PRINT "No files!"
END IF
GOTO [Ready]
CASE "let"
GOSUB [GetLabel]
IF E$<>"" THEN [Ready]
END SELECT
'it must be an expression
GOSUB [ReturnVar]
IF E$<>"" THEN [Ready]
GOSUB [SkipSpace]
GOSUB [GetChar]
IF C$<>"=" THEN
E$="'=' expected"
GOTO [Ready]
END IF
C = C + 1 : T=V
IF NOT(arrayFlag) THEN simpleFlag = TRUE 'left side is a simple variable
GOSUB [GetExpression] 'get the right side which could be an expression
IF E$<>"" THEN [Ready]
IF simpleFlag THEN
A(T)=N 'set the value of simple variable
ELSE
Array(T)=N 'set the value of the array
END IF
arrayFlag = FALSE : simpleFlag = FALSE
[FinishStatement]
GOSUB [SkipSpace]
GOSUB [GetChar]
IF C$=":" THEN
C = C + 1 : GOTO [NextStatement]
ELSE
IF C$<>"" THEN
E$="End of statement expected"
GOTO [Ready]
END IF
END IF
IF L=26 THEN [Ready]
L = L + 1 : C=1
IF L=126 THEN
E$="Program Overflow"
GOTO [Ready]
END IF
[FinishStatement2]
B$=A$(L)
IF B$="" THEN [Ready]
GOTO [Exec]
[ExitTinyBAS] 'end the program
PRINT "Thanks for using Tiny BASIC."
END
[EnterLine]
L=27 : C=1 : T=N
[NextLine]
GOSUB [GetNumber]
B=(N<T) AND (N<>0) AND (L<126)
IF B=TRUE THEN
L = L + 1 : C=1 : GOTO [NextLine]
END IF
IF L=126 THEN
E$="Program Overflow"
GOTO [EndEnterLine]
END IF
IF T<>N THEN
FOR I=L to 125
diffI = (125+L)-I
B=diffI-1 : A$(diffI)=A$(B)
NEXT I
END IF
A$(L)=Z$
GOSUB [SkipSpace]
IF C$="" THEN
FOR I=L TO 124
B=I+1 : A$(I)=A$(B)
NEXT I
END IF
[EndEnterLine]
RETURN
[GetExpression] 'numeric expressions only
A(53)=0 : S=53
GOSUB [BoolExpression]
N=A(S) : GOTO [EndExpression]
[BoolExpression]
GOSUB [AddExpression]
GOSUB [SkipSpace]
GOSUB [GetChar]
[NextBool]
SELECT CASE C$
CASE "="
C = C + 1 : GOSUB [AddExpression]
B=S-1 : A(B)=A(B)=A(S) : S = S - 1
CASE ">"
C = C + 1 : GOSUB [GetChar]
IF C$="=" THEN
C = C + 1 : GOSUB [AddExpression]
B=S-1 : A(B)=A(B)>=A(S) : S = S - 1
ELSE
GOSUB [AddExpression]
B=S-1 : A(B)=A(B)>A(S) : S = S - 1
END IF
CASE "<"
C = C + 1 : GOSUB [GetChar]
SELECT CASE C$
CASE "="
C = C + 1 : GOSUB [AddExpression]
B=S-1 : A(B)=A(B)<=A(S) : S = S - 1
CASE ">"
C = C + 1 : GOSUB [AddExpression]
B=S-1 : A(B)=A(B)<>A(S) : S = S - 1
CASE ELSE
GOSUB [AddExpression]
B=S-1 : A(B)=A(B)<A(S) : S = S - 1
END SELECT
END SELECT
GOSUB [SkipSpace]
GOSUB [GetChar]
B=ASC(C$) : B=(B>=60) AND (B<=62)
IF B=TRUE THEN [NextBool]
GOTO [EndExpression]
[AddExpression]
GOSUB [MulExpression]
GOSUB [SkipSpace]
GOSUB [GetChar]
[NextAdd]
SELECT CASE C$
CASE "+"
C = C + 1 : GOSUB [MulExpression]
B=S-1 : A(B)=A(B)+A(S) : S = S - 1
CASE "-"
C = C + 1 : GOSUB [MulExpression]
B=S-1 : A(B)=A(B)-A(S) : S = S - 1
END SELECT
GOSUB [SkipSpace]
GOSUB [GetChar]
B=ASC(C$) : B=(B=43) OR (B=45)
IF B=TRUE THEN [NextAdd]
GOTO [EndExpression]
[MulExpression]
GOSUB [GroupExpression]
GOSUB [SkipSpace]
GOSUB [GetChar]
[NextMul]
SELECT CASE C$
CASE "*"
C = C + 1 : GOSUB [GroupExpression]
B=S-1 : A(B)=A(B)*A(S) : S = S - 1
CASE "/"
C = C + 1 : GOSUB [GroupExpression]
B=A(S)
IF B=0 THEN
IF E$="" THEN E$="Division by zero"
S = S - 1 : GOTO [EndExpression]
ELSE
B=S-1 : A(B)=A(B)/A(S) : S = S - 1
END IF
CASE " "
C = C + 1 : GOSUB [GroupExpression]
B=A(S)
IF B=0 THEN
IF E$="" THEN E$="Division by zero"
S = S - 1 : GOTO [EndExpression]
ELSE
B=S-1 : A(B)=A(B) mod A(S) : S = S - 1
END IF
END SELECT
GOSUB [SkipSpace]
GOSUB [GetChar]
B=ASC(C$)
B=(B=42) OR (B=47) OR (B=92)
IF B=TRUE THEN [NextMul]
GOTO [EndExpression]
[GroupExpression]
GOSUB [SkipSpace]
GOSUB [GetChar]
SELECT CASE C$
CASE "("
C = C + 1 : GOSUB [BoolExpression]
GOSUB [SkipSpace]
GOSUB [GetChar]
IF C$<>")" THEN
IF E$="" THEN E$="Missing ')'"
GOTO [EndExpression]
END IF
C = C + 1
CASE ""
IF E$="" THEN E$="Invalid Factor"
CASE ELSE
B=ASC(C$) : B=(B<48) OR (B>57)
IF B=FALSE THEN
GOSUB [GetNumber]
S = S + 1 : A(S)=N
ELSE
GOSUB [GetLabel]
IF E$<>"" THEN [EndExpression]
B=LEN(D$)
IF B = 1 OR (LEFT$(D$, 2) = "a(" AND RIGHT$(D$,1) = ")") THEN
GOSUB [ReturnVar]
S = S + 1
IF arrayFlag THEN
A(S)=Array(V)
ELSE
A(S)=A(V)
END IF
ELSE
SELECT CASE D$
CASE "milliseconds", "ms"
S = S + 1 : A(S)=time$("ms") 'return number of milliseconds since midnight
CASE "seconds"
S = S + 1 : A(S)=time$("seconds") 'return number of seconds since midnight
CASE ELSE
IF E$="" THEN E$="Function expected"
END SELECT
END IF
END IF
END SELECT
[EndExpression]
RETURN
[GetNumber] 'get the line number if it exists
GOSUB [SkipSpace] 'skip leading spaces
B$=""
[NextNumber]
GOSUB [GetChar] 'get the next character
IF C$="" THEN [GetNumberExit]
B=ASC(C$) 'convert to ASCII character code
B=((B<48) OR (B>57)) AND (B<>46)
IF B=TRUE THEN [GetNumberExit] 'Abort if not a digit or decimal point
B$=B$+C$ : C = C + 1 : GOTO [NextNumber] 'Build the number
[GetNumberExit]
N=VAL(B$) 'convert the assembled string to a number
RETURN
[GetVar]
GOSUB [GetLabel]
IF E$<>"" THEN [GetVarExit]
[ReturnVar]
arrayFlag = FALSE
IF LEFT$(D$, 2) = "a(" and RIGHT$(D$,1) = ")" THEN 'possible array variable (i.e. a() )
GOSUB [ExtractArrayIndex]
ELSE 'simple variable (i.e. a-z)
B=ASC(D$) : A=LEN(D$)
A=(A<>1) OR (B<97) OR (B>122)
IF A=FALSE THEN
V=B-70
ELSE
IF E$="" THEN E$="Variable expected"
END IF
END IF
[GetVarExit]
RETURN
[GetLabel]
GOSUB [SkipSpace]
GOSUB [GetChar]
D$="" 'single statement
IF C$="" THEN [GetLabelError]
B=ASC(C$) : B=((B>=97) AND (B<=122)) OR (B=40) OR (B=41) OR ((B>=48) AND (B<=57)) 'letters, parentheses and digits are OK
IF B=FALSE THEN [GetLabelError]
[GetNextLabel]
D$=D$+C$ : C = C + 1
GOSUB [GetChar]
IF C$="" THEN [GetLabelExit]
B=ASC(C$) : B=((B>=97) AND (B<=122)) OR (B=40) OR (B=41) OR ((B>=48) AND (B<=57)) 'letters, parentheses and digits are OK
IF B=TRUE THEN [GetNextLabel]
GOTO [GetLabelExit]
[GetLabelError]
IF E$="" THEN E$="Invalid label"
[GetLabelExit]
RETURN
[SkipSpace] 'skip leading spaces in input
GOSUB [GetChar]
IF C$=" " THEN C = C + 1 : GOTO [SkipSpace] 'skip all leading spaces
RETURN
[GetChar] 'get the next character and change it to lowercase
A$=A$(L) 'efficient? This assignment is made before retrieving each character.
C$=MID$(A$,C,1) : C$=LOWER$(C$)
RETURN
[ExtractArrayIndex] 'get the array index
'the index can be a number or a simple variable
A$ = MID$(D$, 3, (LEN(D$) - 3))
A = VAL(A$)
IF A = 0 THEN 'index is 0 or it's a variable
B = ASC(LOWER$(A$))
IF (B >= 97) AND (B <= 122) THEN 'it's a variable
arrayFlag = TRUE
V = A(B-70) 'get the index value
IF V = 0 THEN
IF E$="" THEN E$="Array index should be between 1 and "; STR$(ArraySize)
END IF
ELSE
IF E$="" THEN E$="Array index should be between 1 and "; STR$(ArraySize)
END IF
ELSE
IF A > ArraySize THEN
IF E$="" THEN E$="Array index should be between 1 and "; STR$(ArraySize)
ELSE
arrayFlag = TRUE
V = A 'must use array flag to determine where to use the V index
END IF
END IF
RETURN
function fileExists(path$, filename$)
'this function is from the LB4 help file
'dimension the array info$() at the beginning of your program
files path$, filename$, info$()
fileExists = val(info$(0, 0)) 'non zero is true
end function