"can anyone provide live example?".....11 pages in and apparently not!
VB and VC are "off topic" but apparently Scheme/Lisp/Pascal are on topic (I must be misinterpreting the title again)
We have one who makes claims that C will "blow the pants off Basic" but can't tell us how/why. I guess he just read it somewhere.
The statement was made: "Also, what your program does not use does not get linked in, that's great when you want tiny code." So I provided a compiled Windows BASIC "Hello World" that is ~8KB (no dependencies) and it fell on deaf ears.
A data structure example written in C was used as an example of something that couldn't be done in BASIC. It took like 15mins (I'm slow on the keyboard) to replicate it using a 28 year old DOS BASIC and the bonus was improved readability.
The question was too vague to be answered so people have been going off on tangents.
"can anyone provide live example?".....11 pages in and apparently not!
It helps to read the pages if you are going to talk about them:
FFT in C post #14
FFT in BASIC via #78
How live do you want?
Yes, VB and VC are almost certainly off topic. The subject is languages not IDEs. How are you going to run any of the code they generate on Parallax product, or anywhere but on Windows, anyway?
Yes, Scheme/Lisp/Pascal are also off topic, but what the heck, we have flogged the BASIC/C debate to death. It's boring anyway.
So I provided a compiled Windows BASIC "Hello World" that is ~8KB (no dependencies) and it fell on deaf ears.
I noticed that. I don't understand what you mean by it. 8K is huge. OK point taken, a BASIC compiler can also only pull in code that it needs for the program. But heck the young Bill Gates and co. could fit an entire BASIC interpreter in 8K, even 4K.
Mickster, your link goes to a hello.exe file on dropbox. I'm not sure how useful that is for proving your point. A C version of "Hello World" is "void main() { printf("Hello World\n"); }". It compiles to a 4,296 byte CMM binary.
'-------------------------------------------------------------------------------
'
' HELLO.BAS example for PowerBASIC for Windows
' Copyright (c) 1997-2005 PowerBASIC, Inc.
' All Rights Reserved.
'
'-------------------------------------------------------------------------------
#COMPILER PBWIN 9
#COMPILE EXE
' The resource file gives the EXE program the "hello" icon in Explorer,
' and provides it with Windows version information.
#RESOURCE "Hello.pbr"
FUNCTION PBMAIN () AS LONG
MSGBOX "Hello, World!"
END FUNCTION
Are you asserting here BASIC doesn't do threads or is there some other *magic* in the C language that I need to know about?
PowerBASIC is entirely thread-safe, so multi-threaded applications are a breeze. Isn't it good to know your program can handle 2, 3, or 5000 tasks, all at the same time? You can print a report, while still allowing data entry. Watch for a hardware signal, while calculating data services. All the power you need is packed right into the PowerBASIC Thread Statement, along with its simple extensions. There is even a built-in THREAD object that offers a collection of methods which allow you to easily create and maintain additional threads of execution in your programs. Functions, Subroutines, Methods, and Properties can even be marked as THREADSAFE. When a procedure is declared THREADSAFE, PowerBASIC automatically establishes a semaphore which allows only one thread to execute it at a time. Others must wait until the first thread exits the THREADSAFE procedure before they are allowed to begin. This is important to protect global data (global, threaded, static, and instance variables) from corruption by interaction of the threads. PowerBASIC even offers THREADED variables for "Thread Local Storage" -- each THREAD get its own unique copy of the variable -- automatically.
Are you asserting here BASIC doesn't do threads or is there some other *magic* in the C language that I need to know about?
I'm not asserting anything. I just want to see the BASIC version of the program. You don't even need to do the threaded part if you don't want to. A single-threaded BASIC version would be fine.
Once that is under your belt, polish it up with some system calls, and you can put an entire app in 4K.
Ahhhh, those were the days!!
On the other hand, every single byte in this executable file can be accounted for and justified. How many executables have you created lately that you can say that about?
I miss lovingly hand crafting programs so they fit in tiny spaces!
Please tell me how LISP, PASCAL, and any other language that you have discussed, besides BASIC and C is on topic.
EDIT: At least VB and VC apply to C and BASIC
When faced with an unanswerable question, "Why C is better than BASIC , can anyone provide examples?", once one gets bored, why not wander off through the garden and see what other tea trolleys one can topple??
I think some of the off topic discussions have been rather enlightening and thought provoking!
I think some of the off topic discussions have been rather enlightening and thought provoking!
Oh absolutely! In fact, this thread inspired me to pull out my old DOS development system and I am now considering FreeDOS + QuickBASIC for an application that just came up....don't know why I didn't think of it before.
Oh absolutely! In fact, this thread inspired me to pull out my old DOS development system and I am now considering FreeDOS + QuickBASIC for an application that just came up....don't know why I didn't think of it before.
Not to take the OT more OT but.....
Have you tried a Micromite yet? It's a modernized, controller targeted GWBASIC running on PIC32MX devices. Pretty powerful solution on a $5 chip if you like BASIC.
Oh absolutely! In fact, this thread inspired me to pull out my old DOS development system and I am now considering FreeDOS + QuickBASIC for an application that just came up....don't know why I didn't think of it before.
Or if you want to stick with the Prop there are several Basics that have been written for it. You might want to check out the Basic interpreter that runs under spinix. It does a fine job running Star Wars. It is a little slow though. Maybe ebasic would work better. Of course, both of these Basic interpreters were written in C, so if you use either of them you're basically running your Basic program in C. What you really need is a Basic interpreter that was written in Basic. I wonder if one exists.
LOL...Cost/time constraints and I was about to no-quote.
Actually, for all my harping on about QuickBASIC, it turns out to be the glue for a whole bunch of MASM stuff. In fact, I can't tolerate the delays caused by DOS when it decides to stutter for whatever reason so I created a timer interrupt routine to handle the actual machine I/O, This interrupt routine shares data with my QB code so that, when I am running in the QB IDE and decide to suspend/single step through the code, the time critical stuff keeps running, taking care of safety systems, etc. As the I/O status changes, the QB arrays are updated automatically. Being able to make changes in the QB code and continue execution without having to recompile, makes for rapid development and saves scrapping a workpiece (Inconel, stainless steel tubing, etc). My pseudo real-time DOS...LOL
Title INT.ASM Interrupt Control Programs
;Revision History
;Rev 001
;Rev 002
; Call to PDPress added 1/11/94
;Rev 003
; Call to PumpTimer added 6/15/94
;Rev 004
; Call to DeadMan added 4/5/95
;Rev 005
; Call to IntTimer added 1/6/95
option segment:use16
.386
.dosseg
.model medium,basic
public flgoff
public flgseg
public inpoff
public inpseg
public optoff
public optseg
public outoff
public outseg
.data
inpseg dw 0 ;inputs array
inpoff dw 0
outseg dw 0 ;outputs array
outoff dw 0
flgseg dw 0 ;flags array
flgoff dw 0
optoff dw 0 ;options array
optseg dw 0
.code
extrn ButtonHandler:proc
extrn DMCInt:proc
extrn DeadMan:proc
extrn inhand:proc
extrn IntTimer:proc
extrn MandStop:proc
extrn PDPress:proc
extrn ophand:proc
extrn PumpTimer:proc
extrn ScreenTimer:proc
getw MACRO to,from ;get a parameter and save it
mov bx,from
mov ax,[bx]
mov word ptr to,ax
ENDM
install proc inps:ptr word, ino:ptr word, \
ops:ptr word, opo:ptr word, \
fls:ptr word, flo:ptr word, \
opts:ptr word, opto:ptr word
pusha ;save registers
push ds
push es
mov ax,@data ;set data seg
mov ds,ax
;save passed parameters for interrupt handler use
getw inpseg,inps ;get inputs segment
getw inpoff,ino ;get inputs offset
getw outseg,ops ;get outputs segment
getw outoff,opo ;get outputs offset
getw flgseg,fls ;get flags segment
getw flgoff,flo ;get flags offset
getw optseg,opts ;get options segment
getw optoff,opto ;get options segment
mov ax,3508h ;get current interrupt vector
int 21h
mov word ptr cs:oldvec,bx ;save segment
mov word ptr cs:oldvec+2,es ;save segment
cli ;stop interrupt
mov al,36h ;reprogram timer to 8 times
out 43h,al ;normal speed
mov al,0
jmp @F
@@:
jmp @F
@@:
out 40h,al
; mov al,20h
MOV al,4
jmp @F
@@:
jmp @F
@@:
out 40h,al
push cs ;change interrupt vector
pop ds
lea dx, newint
mov ax,2508h
int 21h
sti ;restart interrupt
pop es ;restore
pop ds
popa
ret
install endp
uninst proc
pusha
push ds
push es
push si
push di
cli ;stop interrupts
mov al,36h ;timer back to normal
out 43h,al ;alert for coming values
jmp @F
@@:
jmp @F
@@:
mov al,00h
out 40h,al ;lsb
jmp @F
@@:
jmp @F
@@:
out 40h,al ;msb
lds dx,cs:oldvec ;restore old interrupt
mov ax,2508h
int 21h
sti ;enable interrupts
pop di
pop si
pop es ;restore registers
pop ds
popa
ret
uninst endp
newint proc near
pusha ;save registers
push ds
push es
push si
push di
call IntTimer ;cpu independant interrupt timer
call DeadMan ;deadman relay driver
call inhand ;update inputs
call ButtonHandler ;Pb interlock handler
call MandStop ;stop mandrel on switch
call PDPress ;Pressure die pressure handler
call DMCInt ;DMC comms
call ophand ;update outputs
; allow for speeded up clock
dec cs:counter ;count down
jns exit ;not time yet
; this section runs every eigth interrupt
mov cs:counter,63 ;restart timer
dec cs:SecTimer ;update seconds counter
jns @F
mov cs:sectimer,18 ;restart seconds timer
call ScreenTimer ;do this once per second
call PumpTimer
@@:
pop di
pop si
pop es ;restore registers
pop ds
popa
jmp cs:oldvec ;to normal clock interrupt
exit:
mov al,20h ;issue an EOI
out 20h,al
pop di
pop si
pop es ;restore registers
pop ds
popa
iret ;return from interrupt
oldvec dd 0
counter dw 0
SecTimer dw 18 ;one second(approx) timer
newint endp
end
Am I alone in thinking this train derailed many posts back and the individual cars are now merrily rolling down hill?
Debates on things like the best computer language, religion, and philosophy are an endless quagmire of opinion and beliefs with virtually no facts to justify them.
"can anyone provide live example?".....11 pages in and apparently not!
VB and VC are "off topic" but apparently Scheme/Lisp/Pascal are on topic (I must be misinterpreting the title again)
We have one who makes claims that C will "blow the pants off Basic" but can't tell us how/why. I guess he just read it somewhere.
The statement was made: "Also, what your program does not use does not get linked in, that's great when you want tiny code." So I provided a compiled Windows BASIC "Hello World" that is ~8KB (no dependencies) and it fell on deaf ears.
A data structure example written in C was used as an example of something that couldn't be done in BASIC. It took like 15mins (I'm slow on the keyboard) to replicate it using a 28 year old DOS BASIC and the bonus was improved readability.
I think that the source code for linux was mentioned a time or two. It hasn't been posted but I don't think the moderators will allow it all to be posted here! For those interested in wading through the source code could consider the source to Xwindows and emacs.
{******************************************************************************
* *
* TINY PASCAL BASIC *
* *
* 1980 S. A. MOORE *
* *
* Implements a small basic in Pascal. An example of how small a program can *
* be to implement a simple language. *
* Variables are allowed, using the letters "a" thru "z". Integers are denoted *
* by the letters alone. Strings are denoted by "a$" form. *
* The following statements are implemented: *
* *
* input <variable> Reads the contents of the variable from the user. *
* If the variable is integer, a line is read from the *
* user, then any spaces on the line skipped, then a *
* number read. *
* If the variable is string, the entire line is *
* assigned to it, including any spaces. *
* *
* print <expr> [,<expr].. [;] Prints the expression. The expression can be *
* integer or string. If a trailing ";" exists, the next *
* print will resume on the same line. Any number of *
* items may appear to be printed on the same line, *
* separated by ",". *
* *
* goto <integer> Control resumes at the line specified by the integer. *
* Note that no "calculated gotos" are allowed. *
* *
* if <expr> then <statement> The expression must be a integer. If the *
* condition is 0, control resumes on the next line. *
* if the condition is not 0, the statement after "then" *
* is executed (as well as the rest of the line). *
* *
* rem <line> The entire rest of the line is ignored. *
* *
* stop Terminates program execution. The values of variables *
* are not cleared. *
* *
* run All variables are cleared, with integers becoming 0, *
* and strings becoming empty. Then control passes to *
* the first statement in the program. *
* *
* list [<start>[,<end>]] Lists all program lines between the given lines. *
* The default if no lines are given is the starting *
* and ending lines of the entire program. *
* *
* new Clears the entire program and stops execution. *
* *
* [let] <var> = <expr> Assigns the value of the expression to the *
* variable. The variable must be the same type (string *
* or integer) as the expression. The "let" keyword is *
* optional. *
* *
* bye Exits basic for the operating system. *
* *
* Expressions can contain the following operators: *
* *
* <, >, =, <>, <=, >= Comparision. *
* +, -, *, /, mod Basic math. *
* left$(<str>, <expr>) The leftmost characters of the string. *
* right$(<str>, <expr>) The rightmost characters of the string. *
* mid$(<str>, <start>, <len>) The middle characters of the string. *
* str$(<expr>) The string form of the integer expression. *
* val(<str>) The integer equivalent of the string. *
* chr(<str>) The ascii value of the first character. *
* *
* The internal form of the program is keyword compressed for effiency, which *
* both allows for a smaller internal program, and simplifies the decoding of *
* keywords. *
* *
* *
* Notes: *
* *
* 1. If the program store were of the same form as basic strings, routines *
* that handle both in common could be used (example: getting a number from *
* the string). *
* *
******************************************************************************}
program basics(input, output);
label 88, 77, 99;
const maxlin = 9999; { maximum line number }
maxpgm = 100; { maximum line store }
maxstk = 10; { maximum temp count }
maxkey = 29; { maximum key store }
{ key codes }
cinput = 1; cprint = 2; cgoto = 3; cif = 4;
crem = 5; cstop = 6; crun = 7; clist = 8;
cnew = 9; clet = 10; cbye = 11; clequ = 12;
cgequ = 13; cequ = 14; cnequ = 15; cltn = 16;
cgtn = 17; cadd = 18; csub = 19; cmult = 20;
cdiv = 21; cmod = 22; cleft = 23; cright = 24;
cmid = 25; cthen = 26; cstr = 27; cval = 28;
cchr = 29;
type string10 = packed array [1..10] of char; { key }
string80 = packed array [1..80] of char; { general string }
bstring80 = record
len : integer;
str : string80
end;
vartyp = (tint, tstr); { variable type }
{ error codes }
errcod = (eitp, estate, eexmi, eeque, estyp, epbful, eiovf, evare,
elabnf, einte, econv, elntl, ewtyp, erpe, eexc, emqu,
eifact, elintl, estrovf, eedlexp, elpe, ecmaexp, estre,
estrinx);
var prgm: array [0..maxpgm] of string80; { program store }
strs: array ['a'..'z'] of bstring80; { string store }
ints: array ['a'..'z'] of integer; { integer store }
keywd: array [cinput..cchr] of string10; { keywords }
temp: array [1..maxstk] of record
typ : vartyp;
int : integer;
bstr : bstring80
end;
prgmc, { program counter (0 = input line) }
top, { current temps top }
linec: integer; { character position }
{ print key compressed line }
procedure prtlin(var str : string80);
var i, j: integer;
procedure prtkey(var str : string10);
var i, j: integer;
begin { prtkey }
j := 10;
while (str[j] = ' ') and (j > 0) do j := j - 1;
j := j + 1;
i := 1;
while i < j do begin write(str[i]); i := i + 1 end
end; { prtkey }
begin { prtlin }
j := 80;
while (str[j] = ' ') and (j > 0) do j := j - 1;
j := j + 1;
i := 1;
while i < j do begin
if ord(str[i]) < ord(' ') then prtkey(keywd[ord(str[i])])
else write(str[i]);
i := i + 1
end;
writeln
end; { prtlin }
{ print error }
procedure prterr(err : errcod);
begin
if prgmc <> 0 then prtlin(prgm[prgmc]);
write('*** ');
case err of
eitp: writeln('Interpreter error');
estate: writeln('Statement expected');
eexmi: writeln('Expression must be integer');
eeque: writeln('"=" expected');
estyp: writeln('Operands not of same type');
epbful: writeln('Program buffer full');
eiovf: writeln('Input overflow');
evare: writeln('Variable expected');
elabnf: writeln('Statement label not found');
einte: writeln('Integer expected');
econv: writeln('Conversion error');
elntl: writeln('Line number too large');
ewtyp: writeln('Operand(s) of wrong type');
erpe: writeln('")" expected');
eexc: writeln('Expression too complex');
emqu: writeln('Missing quote');
eifact: writeln('Invalid factor');
elintl: writeln('Line number too large');
estrovf: writeln('String overflow');
eedlexp: writeln('End of line expected');
elpe: writeln('"(" expected');
ecmaexp: writeln('"," expected');
estre: writeln('String expected');
estrinx: writeln('String indexing error')
end;
goto 88 { loop to ready }
end;
{ check character }
function chkchr : char;
var c: char;
begin
if linec <= 80 then c := prgm[prgmc][linec]
else c := ' ';
chkchr := c
end;
{ check end of line }
function chkend: boolean;
begin
chkend := linec > 80 { past end of line }
end;
{ get character }
function getchr: char;
begin
getchr := chkchr;
if not chkend then linec := linec + 1
end;
{ check next character }
function chknxt(c : char) : boolean;
begin
chknxt := c = chkchr;
if c = chkchr then c := getchr
end;
{ skip spaces }
procedure skpspc;
var c: char;
begin
while (chkchr = ' ') and not chkend do c := getchr;
end;
{ check end of statement }
function chksend: boolean;
begin
skpspc; { skip spaces }
chksend := chkend or (chkchr = ':') { check eoln or ':' }
end;
{ check null string }
function null(var str : string80) : boolean;
var i: integer;
f: boolean;
begin
f := true;
for i := 1 to 80 do if str[i] <> ' ' then f := false;
null := f
end;
{ check digit }
function digit(c : char) : boolean;
begin
digit := (ord(c) >= ord('0')) and (ord(c) <= ord('9'))
end;
{ convert to lower case }
function lcase(c : char) : char;
begin
if (ord(c) >= ord('A')) and (ord(c) <= ord('Z')) then
c := chr(ord(c) - ord('A') + ord('a'));
lcase := c
end;
{ check alphabetical }
function alpha(c : char) : boolean;
begin
alpha := (ord(lcase(c)) >= ord('a')) and
(ord(c) <= ord('z'))
end;
{ parse leading integer }
function lint(var str : string80) : integer;
var i, v: integer;
b: boolean;
begin
v := 0;
i := 1;
while (i < 80) and (str[i] = ' ') do i := i + 1;
repeat
if digit(str[i]) then begin
v := v*10 + (ord(str[i]) - ord('0'));
if i <> 80 then begin
i := i + 1;
b := false
end else b := true
end else b := true
until b;
lint := v
end;
{ search label }
function schlab(lab : integer):integer;
var i: integer;
begin
i := 1;
while (lab <> lint(prgm[i])) and (i <= maxpgm) do i := i + 1;
if lab <> lint(prgm[i]) then prterr(elabnf);
schlab := i
end;
{ input string }
procedure inpstr(var str : string80);
var i: integer;
begin
for i := 1 to 80 do str[i] := ' ';
i := 1;
while (i <= 80) and not eoln do begin
read(str[i]);
i := i + 1
end;
readln;
if (i > 80) then prterr(eiovf)
end;
{ parse variable reference }
function getvar : char;
begin
if not alpha(chkchr) then prterr(evare);
getvar := lcase(getchr)
end;
{ enter line to store }
procedure enter(var str : string80);
var line, i, j, k: integer;
f: boolean;
begin
line := lint(str);
if line > maxlin then prterr(elintl); { input line number to large }
i := 1;
f := false;
repeat
if null(prgm[i]) then f := true
else if lint(prgm[i]) < line then begin
i := i + 1;
if i > maxpgm then f := true
end else f := true
until f;
if i > maxpgm then prterr(epbful);
if null(prgm[i]) then prgm[i] := str
else if lint(prgm[i]) = line then begin
j := 1;
while (str[j] = ' ') and (j < 80) do j := j + 1;
while digit(str[j]) and (j < 80) do j := j + 1;
while (str[j] = ' ') and (j < 80) do j := j + 1;
if j = 80 then begin
for k := i to maxpgm - 1 do prgm[k] := prgm[k + 1];
for j := 1 to 80 do prgm[maxpgm][j] := ' '
end else prgm[i] := str
end else if not null(prgm[maxpgm]) then prterr(epbful)
else begin
for k := maxpgm downto i + 1 do prgm[k] := prgm[k - 1];
prgm[i] := str
end
end;
{ compress keys }
procedure keycom(var str : string80);
var ts: string80;
k, i1, i2: integer;
f: boolean;
c: char;
function matstr(var stra: string80; var i: integer;
var strb: string10): boolean;
var i1, i2: integer;
f: boolean;
begin { matstr }
i1 := i;
i2 := 1;
repeat
if strb[i2] = ' ' then f := false
else if lcase(stra[i1]) = lcase(strb[i2]) then begin
f := true;
i1 := i1 + 1;
i2 := i2 + 1
end
else f := false
until not f or (i1 > 80) or (i2 > 10);
if i2 > 10 then begin f := true; i := i1 end
else if strb[i2] = ' ' then begin f := true; i := i1 end
else f := false;
matstr := f
end; { matstr }
{}
begin { keycom }
for i2 := 1 to 80 do ts[i2] := ' ';
i1 := 1;
i2 := 1;
repeat
if str[i1] = '"' then begin
ts[i2] := '"';
i1 := i1 + 1;
i2 := i2 + 1;
c := ' ';
while (i1 <= 80) and (c <> '"') do begin
c := str[i1];
ts[i2] := str[i1];
i1 := i1 + 1;
i2 := i2 + 1
end
end else if str[i1] = ' ' then begin
ts[i2] := str[i1];
i1 := i1 + 1;
i2 := i2 + 1
end else begin
k := 1;
f := false;
while (k <= maxkey) and not f do
begin
f := matstr(str, i1, keywd[k]);
k := k + 1
end;
if f then ts[i2] := chr(k - 1)
else begin ts[i2] := str[i1]; i1 := i1 + 1 end;
i2 := i2 + 1
end
until i1 > 80;
for i1 := 1 to 80 do str[i1] := ts[i1]
{ this diagnostic prints the resulting tolken sequence }
{;for i1 := 1 to 80 do write(ord(str[i1]), ' ');}
end; { keycom }
{ get integer }
function getint: integer;
var v: integer;
begin
v := 0;
skpspc;
if not digit(chkchr) then prterr(einte);
repeat v := v*10 + (ord(getchr) - ord('0'))
until not digit(chkchr);
getint := v
end;
{ get integer from string }
function getval(var str: string80): integer;
var i: integer;
begin
i := 1;
while (i <= 80) and (str[i] = ' ') do i := i + 1;
if not digit(str[i]) then prterr(einte);
getval := lint(str);
while (i < 80) and digit(str[i]) do i := i + 1;
while (i < 80) and (str[i] = ' ') do i := i + 1;
if i <> 80 then prterr(econv)
end;
{ get integer from basic string }
function getbval(var str: bstring80): integer;
var i, v: integer;
begin
i := 1;
while (i <= str.len) and (str.str[i] = ' ') do i := i + 1; { skip spaces }
if not digit(str.str[i]) then prterr(einte); { number not present }
v := 0; { clear result }
while (i <= str.len) and digit(str.str[i]) do begin { parse digit }
v := v*10+ord(str.str[i])-ord('0'); { scale, convert and add in digit }
i := i+1 { next character }
end;
while (i <= str.len) and (str.str[i] = ' ') do i := i + 1;
if i <= str.len then prterr(econv);
getbval := v { return result }
end;
{ place integer to string }
procedure putbval(var str: bstring80; v: integer);
var p: integer; { power holder }
i: integer; { string index }
begin
str.len := 0; { clear result string }
p := 10000; { set maximum power }
i := 1; { set 1st character }
if v < 0 then begin { negative }
str.str[i] := '-'; { place minus sign }
i := i + 1; { next character }
v := -v { negate number }
end;
while p <> 0 do begin { fit powers }
str.str[i] := chr(v div p+ord('0')); { place digit }
if str.str[1] = '-' then begin { negative }
if (str.str[2] <> '0') or (p = 1) then i := i + 1; { next digit }
end else { positive }
if (str.str[1] <> '0') or (p = 1) then i := i + 1; { next digit }
v := v mod p; { remove from value }
p := p div 10 { find next power }
end;
str.len := i-1 { set length of string }
end;
{ print basic string }
procedure prtbstr(var bstr: bstring80);
var i: integer;
begin
for i := 1 to bstr.len do write(bstr.str[i]);
end;
{ input basic string }
procedure inpbstr(var bstr: bstring80);
var i: integer;
begin
for i := 1 to 80 do bstr.str[i] := ' ';
i := 1;
while (i < 80) and not eoln do begin
read(bstr.str[i]);
i := i + 1
end;
if (i > 80) and not eoln then prterr(eiovf);
readln;
bstr.len := i
end;
{ concatenate basic strings }
procedure cat(var bstra, bstrb: bstring80);
var i: integer; { index for string }
begin
if (bstra.len + bstrb.len) > 80 then prterr(estrovf); { string overflow }
{ copy source after destination }
for i := 1 to bstrb.len do bstra.str[bstra.len+i] := bstrb.str[i];
bstra.len := bstra.len + bstrb.len { set new length }
end;
{ check stack items equal }
function chkequ : boolean;
begin
if (temp[top].typ <> tint) or (temp[top - 1].typ <> tint) then
prterr(ewtyp);
chkequ := temp[top - 1].int = temp[top].int
end;
{ check stack items less than }
function chkltn: boolean;
begin
if (temp[top].typ <> tint) or (temp[top - 1].typ <> tint)
then prterr(ewtyp);
chkltn := temp[top - 1].int < temp[top].int
end;
{ check stack items greater than }
function chkgtn: boolean;
begin
if (temp[top].typ <> tint) or (temp[top - 1].typ <> tint)
then prterr(ewtyp);
chkgtn := temp[top - 1].int > temp[top].int
end;
{ set tos true }
procedure settrue;
begin
temp[top].typ := tint;
temp[top].int := 1
end;
{ set tos false }
procedure setfalse;
begin
temp[top].typ := tint;
temp[top].int := 0
end;
{ clear program store }
procedure clear;
var x, y: integer;
c: char;
begin
for x := 1 to maxpgm do
for y := 1 to 80 do prgm[x][y] := ' ';
for c := 'a' to 'z' do strs[c].len := 0;
for c := 'a' to 'z' do ints[c] := 0;
prgmc := 0;
linec := 1;
top := 1
end;
{ clear variable store }
procedure clrvar;
var c: char;
begin
for c := 'a' to 'z' do strs[c].len := 0;
for c := 'a' to 'z' do ints[c] := 0;
prgmc := 0;
linec := 1;
top := 1
end;
{ execute string }
procedure exec;
label 1; { exit procedure }
var c: char;
{ execute statement }
procedure stat;
var x, y: integer;
c: char;
s: string80;
b: boolean;
{ parse expression }
procedure expr;
{ parse simple expression }
procedure sexpr;
{ parse term }
procedure term;
{ parse factor }
procedure factor;
var i: integer;
c: char;
begin { factor }
skpspc;
c := chkchr; { save starting character }
if chknxt('(') then begin
expr;
if not chknxt(')') then prterr(erpe)
end else if chknxt(chr(cadd)) then begin
factor;
if temp[top].typ <> tint then prterr(ewtyp)
end else if chknxt(chr(csub)) then begin
factor;
if temp[top].typ <> tint then prterr(ewtyp);
temp[top].int := - temp[top].int
end else if chknxt('"') then begin
top := top + 1;
if top > maxstk then prterr(eexc);
temp[top].typ := tstr;
i := 1;
while (i <= 80) and (chkchr <> '"') do begin
temp[top].bstr.str[i] := getchr;
i := i + 1
end;
if not chknxt('"') then prterr(emqu);
temp[top].bstr.len := i - 1
end else if digit(chkchr) then begin
top := top + 1;
if top > maxstk then prterr(eexc);
temp[top].typ := tint;
temp[top].int := getint
end else if alpha(chkchr) then begin
top := top + 1;
if top > maxstk then prterr(eexc);
c := getvar;
if chknxt('$') then begin
temp[top].typ := tstr;
temp[top].bstr := strs[c]
end else begin
temp[top].typ := tint;
temp[top].int := ints[c]
end
end else if chknxt(chr(cleft)) or chknxt(chr(cright)) or
chknxt(chr(cmid)) then begin
{ left$, right$ }
skpspc; { skip spaces }
if not chknxt('(') then prterr(elpe); { '(' expected }
expr; { parse expression }
if temp[top].typ <> tstr then prterr(estre); { string expected }
skpspc; { skip spaces }
if not chknxt(',') then prterr(ecmaexp); { ',' expected }
expr; { parse expression }
if temp[top].typ <> tint then prterr(einte); { integer expected }
skpspc; { skip spaces }
if c <> chr(cmid) then begin { left$ or right$ }
if not chknxt(')') then prterr(erpe); { ')' expected }
if temp[top].int > temp[top-1].bstr.len then prterr(estrinx);
if c = chr(cright) then { right$ }
for i := 1 to temp[top].int do { move string left }
temp[top-1].bstr.str[i] :=
temp[top-1].bstr.str[i+temp[top-1].bstr.len-temp[top].int];
temp[top-1].bstr.len := temp[top].int; { set new length left }
top := top-1 { clean stack }
end else begin { mid$ }
if not chknxt(',') then prterr(ecmaexp); { ',' expected }
expr; { parse end expression }
if temp[top].typ <> tint then prterr(einte); { integer expected }
skpspc; { skip spaces }
if not chknxt(')') then prterr(erpe); { ')' expected }
{ check requested length > string length }
if temp[top].int+temp[top-1].int-1 > temp[top-2].bstr.len then
prterr(estrinx);
for i := 1 to temp[top].int do { move string left }
temp[top-2].bstr.str[i] := temp[top-2].bstr.str[i+temp[top-1].int-1];
temp[top-2].bstr.len := temp[top].int; { set new length left }
top := top-2 { clean stack }
end
end else if chknxt(chr(cchr)) then begin { chr }
if not chknxt('(') then prterr(elpe); { '(' expected }
expr; { parse expression }
if temp[top].typ <> tstr then prterr(estre); { string expected }
skpspc; { skip spaces }
if not chknxt(')') then prterr(erpe); { ')' expected }
if temp[top].bstr.len < 1 then prterr(estrinx); { check valid }
c := temp[top].bstr.str[1]; { get the 1st character }
temp[top].typ := tint; { change to integer }
temp[top].int := ord(c) { place result }
end else if chknxt(chr(cval)) then begin { val }
if not chknxt('(') then prterr(elpe); { '(' expected }
expr; { parse expression }
if temp[top].typ <> tstr then prterr(estre); { string expected }
skpspc; { skip spaces }
if not chknxt(')') then prterr(erpe); { ')' expected }
i := getbval(temp[top].bstr); { get string value }
temp[top].typ := tint; { change to integer }
temp[top].int := i { place result }
end else if chknxt(chr(cstr)) then begin { str$ }
if not chknxt('(') then prterr(elpe); { '(' expected }
expr; { parse expression }
if temp[top].typ <> tint then prterr(einte); { integer expected }
skpspc; { skip spaces }
if not chknxt(')') then prterr(erpe); { ')' expected }
i := temp[top].int; { get value }
temp[top].typ := tstr; { change to string }
putbval(temp[top].bstr, i) { place value in ascii }
end else prterr(eifact)
end; { factor }
begin { term }
factor;
skpspc;
while ord(chkchr) in [cmult, cdiv, cmod] do begin
case ord(getchr) of { tolken }
cmult: begin { * }
factor;
if (temp[top].typ <> tint) or
(temp[top - 1].typ <> tint) then prterr(ewtyp);
temp[top - 1].int := temp[top - 1].int * temp[top].int;
top := top - 1
end;
cdiv: begin { / }
factor;
if (temp[top].typ <> tint) or
(temp[top - 1].typ <> tint) then prterr(ewtyp);
temp[top - 1].int := temp[top - 1].int div temp[top].int;
top := top - 1
end;
cmod: begin { mod }
factor;
if (temp[top].typ <> tint) or
(temp[top - 1].typ <> tint) then prterr(ewtyp);
temp[top - 1].int := temp[top - 1].int mod
temp[top].int;
top := top - 1
end
end;
skpspc { skip spaces }
end
end; { term }
begin { sexpr }
term;
skpspc;
while ord(chkchr) in [cadd, csub] do begin
case ord(getchr) of { tolken }
cadd: begin
term;
if temp[top].typ = tstr then begin
if temp[top - 1].typ <> tstr then prterr(estyp);
cat(temp[top - 1].bstr, temp[top].bstr);
top := top - 1
end else begin
if temp[top - 1].typ <> tint then prterr(estyp);
temp[top - 1].int :=
temp[top - 1].int + temp[top].int;
top := top - 1;
end
end;
csub: begin { - }
term;
if (temp[top].typ <> tint) or
(temp[top - 1].typ <> tint) then prterr(ewtyp);
temp[top - 1].int := temp[top - 1].int - temp[top].int;
top := top - 1
end
end;
skpspc { skip spaces }
end
end; { sexpr }
begin { expr }
sexpr; { parse simple expression }
skpspc; { skip spaces }
while ord(chkchr) in [cequ, cnequ, cltn, cgtn, clequ, cgequ] do begin
case ord(getchr) of { tolken }
cequ: begin
sexpr;
if chkequ then begin top := top - 1; settrue end
else begin top := top - 1; setfalse end
end;
cnequ: begin
sexpr;
if chkequ then begin top := top - 1; setfalse end
else begin top := top - 1; settrue end
end;
cltn: begin
sexpr;
if chkltn then begin top := top - 1; settrue end
else begin top := top - 1; setfalse end
end;
cgtn: begin
sexpr;
if chkgtn then begin top := top - 1; settrue end
else begin top := top - 1; setfalse end
end;
clequ: begin
sexpr;
if chkgtn then begin top := top - 1; setfalse end
else begin top := top - 1; settrue end
end;
cgequ: begin
sexpr;
if chkltn then begin top := top - 1; setfalse end
else begin top := top - 1; settrue end
end
end;
skpspc { skip spaces }
end
end; { expr }
{ process "let" function }
procedure let;
begin
skpspc;
c := getvar;
if chknxt('$') then begin
skpspc;
if not chknxt(chr(cequ)) then
prterr(eeque);
expr;
if temp[top].typ <> tstr then
prterr(estyp);
strs[c] := temp[top].bstr;
top := top - 1
end else begin
skpspc;
if not chknxt(chr(cequ)) then
prterr(eeque);
expr;
if temp[top].typ <> tint then
prterr(estyp);
ints[c] := temp[top].int;
top := top - 1
end
end;
begin { stat }
skpspc;
if ord(chkchr) < ord(' ') then begin
if ord(chkchr) > cbye then prterr(estate);
case ord(getchr) of { statement }
cinput: begin
skpspc;
c := getvar;
if chknxt('$') then inpbstr(strs[c])
else begin
inpstr(s);
ints[c] := getval(s)
end
end;
cprint: begin
repeat { list items }
expr;
if temp[top].typ = tstr then prtbstr(temp[top].bstr)
else write(temp[top].int);
top := top - 1;
skpspc
until not chknxt(','); { until not ',' }
if not chknxt(';') then writeln
end;
cgoto: begin
prgmc := schlab(getint);
goto 1
end;
cif: begin
expr;
if temp[top].typ <> tint then
prterr(eexmi);
if temp[top].int = 0 then begin
top := top - 1;
{ go next line }
if prgmc > 0 then prgmc := prgmc + 1;
goto 1
end;
top := top - 1;
b := chknxt(chr(cthen));
stat
end;
crem: begin
if prgmc > 0 then prgmc := prgmc + 1; { go next line }
goto 1 { exit line executive }
end;
cstop: goto 88;
crun: begin clrvar; prgmc := 1; goto 1 end;
clist: begin
x := 1; { set default list swath }
y := maxpgm;
if not chksend then begin { list swath is specified }
x := schlab(getint);
skpspc;
{ check if end line is specified }
if chknxt(',') then y := schlab(getint)
end;
for x := x to y do { print specified lines }
if not null(prgm[x]) then { line exists in buffer }
prtlin(prgm[x]) { print }
end;
cnew: begin clear; goto 88 end;
clet: let;
cbye: goto 99
end
end else let { default let }
end; { stat }
begin { exec }
linec := 1;
while digit(chkchr) do c := getchr; { skip label }
repeat stat until getchr <> ':';
skpspc;
if not chkend then prterr(eedlexp); { should be at line end }
if prgmc > 0 then prgmc := prgmc + 1;
1:
end; { exec }
begin { executive }
clear;
{ initalize keys }
keywd[cinput] := 'input '; keywd[cprint] := 'print ';
keywd[cgoto] := 'goto '; keywd[cif] := 'if ';
keywd[crem] := 'rem '; keywd[cstop] := 'stop ';
keywd[crun] := 'run '; keywd[clist] := 'list ';
keywd[cnew] := 'new '; keywd[clet] := 'let ';
keywd[cbye] := 'bye '; keywd[clequ] := '<= ';
keywd[cgequ] := '>= '; keywd[cequ] := '= ';
keywd[cnequ] := '<> '; keywd[cltn] := '< ';
keywd[cgtn] := '> '; keywd[cadd] := '+ ';
keywd[csub] := '- '; keywd[cmult] := '* ';
keywd[cdiv] := '/ '; keywd[cmod] := 'mod ';
keywd[cleft] := 'left$ '; keywd[cright] := 'right$ ';
keywd[cmid] := 'mid$ '; keywd[cthen] := 'then ';
keywd[cstr] := 'str$ '; keywd[cval] := 'val ';
keywd[cchr] := 'chr ';
writeln;
writeln('Tiny basic interpreter vs. 0.1 Copyright (C) 1994 S. A. Moore');
writeln;
88: while true do begin
writeln('Ready');
77: prgmc := 0;
linec := 1;
top := 0;
{ get user lines until non-blank }
repeat inpstr(prgm[0]) until not null(prgm[0]);
keycom(prgm[0]);
if lint(prgm[0]) > 0 then begin
enter(prgm[0]);
goto 77
end else repeat
exec;
if (prgmc > maxpgm) then prgmc := 0
else if null(prgm[prgmc]) then prgmc := 0
until prgmc = 0
end;
99: writeln
end.
Prop-Basic is super fast...
'
It compiles down into PASM.
'
This is as fast as you can go. No matter what code you write in.
'
The Simple IDE is a joke!!!
'
C , C+++ , C what ever needs so much user input. I just don't like to type that much.
'
Why Parallax bailed on Basic is beyond me????....This is what founded the company.
Wow, PropBasic compiles down to PASM! HOT DOG, I must try it.
Regarding the biggest downside of C,
there are some rather daunting formalities that the plain vanila beginner might become dismayed with.
A. The Preprocessor
B. Syntax Checking
C. Object Code generation
D. Linking
All these steps have good reasons to exist. But for a begineer, there are more ways to mess up.
In the beginning, too much formality will often chase away otherwise able learners. So why bother to load up the new student until they have ambitions for greater things.
Heater may know a lot, but he certainly doesn't think like an educator. And when someone asked why Basic or C, I strongly suspect they are looking to begin learning --- not to add to their professional development.
PropBasic might just appeal to the many users that have felt unable to grasp SPIN and Object Oriented Programing. SPIN is a great language, but it has scared off a lot of naive-but-willing-to-learn new users.
So this is wonderful as Parallax is filling in the gaps in a solid pathway to learning towards becoming a pro.
:-)
Personally, I will never look at Pascal, and Lisp drove me crazy when I attempted to do so. They do have their uses, but either in history or advance study.
BASIC is a lot easier for a non-programmer to read. (Excluding that MS stuff!)
C is a much more powerful language but for what the average person will do BASIC gets the job done.
C is also a lot more abstract and it lacks many of the convenience and safety features that BASIC has such as error checking and garbage collection.
Careful where you stick that C pointer or you might crash your system.
Loopy, I found Spin to very similar with PBASIC though there are some differences. I learned PASCAL after having learned BASIC and it made learning C a lot easier.
When I was at high school, we had introductionary course for programming languages. I liked COBOL, since it looked like normal human readable code. And I disliked ALGOL, since it used a lot of non human friendly symbols such as &[]\">>> etc. Who knew then, that this junk going to grow and later give us Pascal and C
Now that is a step to far. One should not speak ill of the dead. ALGOL was a wonderful thing. The first language to properly express, indeed define, structured programming as we know it today. Even modern BASICS follow in the footsteps of ALGOL with their if/else, while, for, do, named functions, data structures etc, etc, etc.
I'm not sure which ALGOL you were shown that was made ugly for you with &[]\">>> etc. I learned ALGOL as my third programming language and I don't recall having any such trouble. Mind you I don't remember much. I seem to recall it looked like this example for wikipedea:
[B]procedure[/B] Absmax(a) Size:(n, m) Result:(y) Subscripts:(i, k);
[B]value[/B] n, m; [B]array[/B] a; [B]integer[/B] n, m, i, k;[B] real[/B] y;
[B]comment[/B] The absolute greatest element of the matrix a, of size n by m
is transferred to y, and the subscripts of this element to i and k;
[B]begin[/B]
[B]integer[/B] p, q;
y := 0; i := k := 1;
[B]for[/B] p := 1 [B]step[/B] 1 [B]until[/B] n [B]do[/B]
[B]for[/B] q := 1 [B]step[/B] 1 [B]until[/B] m do
[B]if[/B] abs(a[p, q]) > y [B]then[/B]
[B]begin[/B] y := abs(a[p, q]);
i := p; k := q
[B]end[/B]
[B]end[/B] [B]Absmax[/B]
Well, that wikipedia example perfectly shows my understanding of "ugly":
1. Why it has : in front of =
2. Why some lines end with ;, while others - not
3. "for p := 1 step 1 until n do" - what this line does, it is not possible to understand from human knowing of english language, while basic is much closer to "real" language in such constructions.
Well, that wikipedia example perfectly shows my understanding of "ugly":
1. Why it has : in front of =
2. Why some lines end with ;, while others - not
3. "for p := 1 step 1 until n do" - what this line does, it is not possible to understand from human knowing of english language, while basic is much closer to "real" language in such constructions.
It seems that your definition of "ugliness" is "anything that doesn't look exactly like Basic". Given that, there is no answer to your original question but "Basic". Now you have your answer so discussion can end.
Comments
Tell us all about Provisional Patents Mick
FFT in C post #14
FFT in BASIC via #78
How live do you want?
Yes, VB and VC are almost certainly off topic. The subject is languages not IDEs. How are you going to run any of the code they generate on Parallax product, or anywhere but on Windows, anyway?
Yes, Scheme/Lisp/Pascal are also off topic, but what the heck, we have flogged the BASIC/C debate to death. It's boring anyway. I noticed that. I don't understand what you mean by it. 8K is huge. OK point taken, a BASIC compiler can also only pull in code that it needs for the program. But heck the young Bill Gates and co. could fit an entire BASIC interpreter in 8K, even 4K.
Here is some small for you: http://www.muppetlabs.com/~breadbox/software/tiny/teensy.html
Once that is under your belt, polish it up with some system calls, and you can put an entire app in 4K.
'------------------------------------------------------------------------------- ' ' HELLO.BAS example for PowerBASIC for Windows ' Copyright (c) 1997-2005 PowerBASIC, Inc. ' All Rights Reserved. ' '------------------------------------------------------------------------------- #COMPILER PBWIN 9 #COMPILE EXE ' The resource file gives the EXE program the "hello" icon in Explorer, ' and provides it with Windows version information. #RESOURCE "Hello.pbr" FUNCTION PBMAIN () AS LONG MSGBOX "Hello, World!" END FUNCTIONAre you asserting here BASIC doesn't do threads or is there some other *magic* in the C language that I need to know about?
Please tell me how LISP, PASCAL, and any other language that you have discussed, besides BASIC and C is on topic.
EDIT: At least VB and VC apply to C and BASIC
Ahhhh, those were the days!!
I miss lovingly hand crafting programs so they fit in tiny spaces!
When faced with an unanswerable question, "Why C is better than BASIC , can anyone provide examples?", once one gets bored, why not wander off through the garden and see what other tea trolleys one can topple??
I think some of the off topic discussions have been rather enlightening and thought provoking!
I agree. I just don't think it was appropriate for Heater to single me out, when he is all over the place himself.
Oh absolutely! In fact, this thread inspired me to pull out my old DOS development system and I am now considering FreeDOS + QuickBASIC for an application that just came up....don't know why I didn't think of it before.
This always happens when we get in language skirmishes, ( not wars)
Carry on.
Over three years and he still carries a grudge
http://forums.parallax.com/showthread.php/137210-Bragging-Rights!!!-The-Wire-Bending-CNC-and-the-Patent-Application/page2
Not to take the OT more OT but.....
Have you tried a Micromite yet? It's a modernized, controller targeted GWBASIC running on PIC32MX devices. Pretty powerful solution on a $5 chip if you like BASIC.
LOL...Cost/time constraints and I was about to no-quote.
Actually, for all my harping on about QuickBASIC, it turns out to be the glue for a whole bunch of MASM stuff. In fact, I can't tolerate the delays caused by DOS when it decides to stutter for whatever reason so I created a timer interrupt routine to handle the actual machine I/O, This interrupt routine shares data with my QB code so that, when I am running in the QB IDE and decide to suspend/single step through the code, the time critical stuff keeps running, taking care of safety systems, etc. As the I/O status changes, the QB arrays are updated automatically. Being able to make changes in the QB code and continue execution without having to recompile, makes for rapid development and saves scrapping a workpiece (Inconel, stainless steel tubing, etc). My pseudo real-time DOS...LOL
Debates on things like the best computer language, religion, and philosophy are an endless quagmire of opinion and beliefs with virtually no facts to justify them.
Not at all!! I'm enjoying it all from the club car!
I think that the source code for linux was mentioned a time or two. It hasn't been posted but I don't think the moderators will allow it all to be posted here!
A tiny BASIC written in Pascal
{****************************************************************************** * * * TINY PASCAL BASIC * * * * 1980 S. A. MOORE * * * * Implements a small basic in Pascal. An example of how small a program can * * be to implement a simple language. * * Variables are allowed, using the letters "a" thru "z". Integers are denoted * * by the letters alone. Strings are denoted by "a$" form. * * The following statements are implemented: * * * * input <variable> Reads the contents of the variable from the user. * * If the variable is integer, a line is read from the * * user, then any spaces on the line skipped, then a * * number read. * * If the variable is string, the entire line is * * assigned to it, including any spaces. * * * * print <expr> [,<expr].. [;] Prints the expression. The expression can be * * integer or string. If a trailing ";" exists, the next * * print will resume on the same line. Any number of * * items may appear to be printed on the same line, * * separated by ",". * * * * goto <integer> Control resumes at the line specified by the integer. * * Note that no "calculated gotos" are allowed. * * * * if <expr> then <statement> The expression must be a integer. If the * * condition is 0, control resumes on the next line. * * if the condition is not 0, the statement after "then" * * is executed (as well as the rest of the line). * * * * rem <line> The entire rest of the line is ignored. * * * * stop Terminates program execution. The values of variables * * are not cleared. * * * * run All variables are cleared, with integers becoming 0, * * and strings becoming empty. Then control passes to * * the first statement in the program. * * * * list [<start>[,<end>]] Lists all program lines between the given lines. * * The default if no lines are given is the starting * * and ending lines of the entire program. * * * * new Clears the entire program and stops execution. * * * * [let] <var> = <expr> Assigns the value of the expression to the * * variable. The variable must be the same type (string * * or integer) as the expression. The "let" keyword is * * optional. * * * * bye Exits basic for the operating system. * * * * Expressions can contain the following operators: * * * * <, >, =, <>, <=, >= Comparision. * * +, -, *, /, mod Basic math. * * left$(<str>, <expr>) The leftmost characters of the string. * * right$(<str>, <expr>) The rightmost characters of the string. * * mid$(<str>, <start>, <len>) The middle characters of the string. * * str$(<expr>) The string form of the integer expression. * * val(<str>) The integer equivalent of the string. * * chr(<str>) The ascii value of the first character. * * * * The internal form of the program is keyword compressed for effiency, which * * both allows for a smaller internal program, and simplifies the decoding of * * keywords. * * * * * * Notes: * * * * 1. If the program store were of the same form as basic strings, routines * * that handle both in common could be used (example: getting a number from * * the string). * * * ******************************************************************************} program basics(input, output); label 88, 77, 99; const maxlin = 9999; { maximum line number } maxpgm = 100; { maximum line store } maxstk = 10; { maximum temp count } maxkey = 29; { maximum key store } { key codes } cinput = 1; cprint = 2; cgoto = 3; cif = 4; crem = 5; cstop = 6; crun = 7; clist = 8; cnew = 9; clet = 10; cbye = 11; clequ = 12; cgequ = 13; cequ = 14; cnequ = 15; cltn = 16; cgtn = 17; cadd = 18; csub = 19; cmult = 20; cdiv = 21; cmod = 22; cleft = 23; cright = 24; cmid = 25; cthen = 26; cstr = 27; cval = 28; cchr = 29; type string10 = packed array [1..10] of char; { key } string80 = packed array [1..80] of char; { general string } bstring80 = record len : integer; str : string80 end; vartyp = (tint, tstr); { variable type } { error codes } errcod = (eitp, estate, eexmi, eeque, estyp, epbful, eiovf, evare, elabnf, einte, econv, elntl, ewtyp, erpe, eexc, emqu, eifact, elintl, estrovf, eedlexp, elpe, ecmaexp, estre, estrinx); var prgm: array [0..maxpgm] of string80; { program store } strs: array ['a'..'z'] of bstring80; { string store } ints: array ['a'..'z'] of integer; { integer store } keywd: array [cinput..cchr] of string10; { keywords } temp: array [1..maxstk] of record typ : vartyp; int : integer; bstr : bstring80 end; prgmc, { program counter (0 = input line) } top, { current temps top } linec: integer; { character position } { print key compressed line } procedure prtlin(var str : string80); var i, j: integer; procedure prtkey(var str : string10); var i, j: integer; begin { prtkey } j := 10; while (str[j] = ' ') and (j > 0) do j := j - 1; j := j + 1; i := 1; while i < j do begin write(str[i]); i := i + 1 end end; { prtkey } begin { prtlin } j := 80; while (str[j] = ' ') and (j > 0) do j := j - 1; j := j + 1; i := 1; while i < j do begin if ord(str[i]) < ord(' ') then prtkey(keywd[ord(str[i])]) else write(str[i]); i := i + 1 end; writeln end; { prtlin } { print error } procedure prterr(err : errcod); begin if prgmc <> 0 then prtlin(prgm[prgmc]); write('*** '); case err of eitp: writeln('Interpreter error'); estate: writeln('Statement expected'); eexmi: writeln('Expression must be integer'); eeque: writeln('"=" expected'); estyp: writeln('Operands not of same type'); epbful: writeln('Program buffer full'); eiovf: writeln('Input overflow'); evare: writeln('Variable expected'); elabnf: writeln('Statement label not found'); einte: writeln('Integer expected'); econv: writeln('Conversion error'); elntl: writeln('Line number too large'); ewtyp: writeln('Operand(s) of wrong type'); erpe: writeln('")" expected'); eexc: writeln('Expression too complex'); emqu: writeln('Missing quote'); eifact: writeln('Invalid factor'); elintl: writeln('Line number too large'); estrovf: writeln('String overflow'); eedlexp: writeln('End of line expected'); elpe: writeln('"(" expected'); ecmaexp: writeln('"," expected'); estre: writeln('String expected'); estrinx: writeln('String indexing error') end; goto 88 { loop to ready } end; { check character } function chkchr : char; var c: char; begin if linec <= 80 then c := prgm[prgmc][linec] else c := ' '; chkchr := c end; { check end of line } function chkend: boolean; begin chkend := linec > 80 { past end of line } end; { get character } function getchr: char; begin getchr := chkchr; if not chkend then linec := linec + 1 end; { check next character } function chknxt(c : char) : boolean; begin chknxt := c = chkchr; if c = chkchr then c := getchr end; { skip spaces } procedure skpspc; var c: char; begin while (chkchr = ' ') and not chkend do c := getchr; end; { check end of statement } function chksend: boolean; begin skpspc; { skip spaces } chksend := chkend or (chkchr = ':') { check eoln or ':' } end; { check null string } function null(var str : string80) : boolean; var i: integer; f: boolean; begin f := true; for i := 1 to 80 do if str[i] <> ' ' then f := false; null := f end; { check digit } function digit(c : char) : boolean; begin digit := (ord(c) >= ord('0')) and (ord(c) <= ord('9')) end; { convert to lower case } function lcase(c : char) : char; begin if (ord(c) >= ord('A')) and (ord(c) <= ord('Z')) then c := chr(ord(c) - ord('A') + ord('a')); lcase := c end; { check alphabetical } function alpha(c : char) : boolean; begin alpha := (ord(lcase(c)) >= ord('a')) and (ord(c) <= ord('z')) end; { parse leading integer } function lint(var str : string80) : integer; var i, v: integer; b: boolean; begin v := 0; i := 1; while (i < 80) and (str[i] = ' ') do i := i + 1; repeat if digit(str[i]) then begin v := v*10 + (ord(str[i]) - ord('0')); if i <> 80 then begin i := i + 1; b := false end else b := true end else b := true until b; lint := v end; { search label } function schlab(lab : integer):integer; var i: integer; begin i := 1; while (lab <> lint(prgm[i])) and (i <= maxpgm) do i := i + 1; if lab <> lint(prgm[i]) then prterr(elabnf); schlab := i end; { input string } procedure inpstr(var str : string80); var i: integer; begin for i := 1 to 80 do str[i] := ' '; i := 1; while (i <= 80) and not eoln do begin read(str[i]); i := i + 1 end; readln; if (i > 80) then prterr(eiovf) end; { parse variable reference } function getvar : char; begin if not alpha(chkchr) then prterr(evare); getvar := lcase(getchr) end; { enter line to store } procedure enter(var str : string80); var line, i, j, k: integer; f: boolean; begin line := lint(str); if line > maxlin then prterr(elintl); { input line number to large } i := 1; f := false; repeat if null(prgm[i]) then f := true else if lint(prgm[i]) < line then begin i := i + 1; if i > maxpgm then f := true end else f := true until f; if i > maxpgm then prterr(epbful); if null(prgm[i]) then prgm[i] := str else if lint(prgm[i]) = line then begin j := 1; while (str[j] = ' ') and (j < 80) do j := j + 1; while digit(str[j]) and (j < 80) do j := j + 1; while (str[j] = ' ') and (j < 80) do j := j + 1; if j = 80 then begin for k := i to maxpgm - 1 do prgm[k] := prgm[k + 1]; for j := 1 to 80 do prgm[maxpgm][j] := ' ' end else prgm[i] := str end else if not null(prgm[maxpgm]) then prterr(epbful) else begin for k := maxpgm downto i + 1 do prgm[k] := prgm[k - 1]; prgm[i] := str end end; { compress keys } procedure keycom(var str : string80); var ts: string80; k, i1, i2: integer; f: boolean; c: char; function matstr(var stra: string80; var i: integer; var strb: string10): boolean; var i1, i2: integer; f: boolean; begin { matstr } i1 := i; i2 := 1; repeat if strb[i2] = ' ' then f := false else if lcase(stra[i1]) = lcase(strb[i2]) then begin f := true; i1 := i1 + 1; i2 := i2 + 1 end else f := false until not f or (i1 > 80) or (i2 > 10); if i2 > 10 then begin f := true; i := i1 end else if strb[i2] = ' ' then begin f := true; i := i1 end else f := false; matstr := f end; { matstr } {} begin { keycom } for i2 := 1 to 80 do ts[i2] := ' '; i1 := 1; i2 := 1; repeat if str[i1] = '"' then begin ts[i2] := '"'; i1 := i1 + 1; i2 := i2 + 1; c := ' '; while (i1 <= 80) and (c <> '"') do begin c := str[i1]; ts[i2] := str[i1]; i1 := i1 + 1; i2 := i2 + 1 end end else if str[i1] = ' ' then begin ts[i2] := str[i1]; i1 := i1 + 1; i2 := i2 + 1 end else begin k := 1; f := false; while (k <= maxkey) and not f do begin f := matstr(str, i1, keywd[k]); k := k + 1 end; if f then ts[i2] := chr(k - 1) else begin ts[i2] := str[i1]; i1 := i1 + 1 end; i2 := i2 + 1 end until i1 > 80; for i1 := 1 to 80 do str[i1] := ts[i1] { this diagnostic prints the resulting tolken sequence } {;for i1 := 1 to 80 do write(ord(str[i1]), ' ');} end; { keycom } { get integer } function getint: integer; var v: integer; begin v := 0; skpspc; if not digit(chkchr) then prterr(einte); repeat v := v*10 + (ord(getchr) - ord('0')) until not digit(chkchr); getint := v end; { get integer from string } function getval(var str: string80): integer; var i: integer; begin i := 1; while (i <= 80) and (str[i] = ' ') do i := i + 1; if not digit(str[i]) then prterr(einte); getval := lint(str); while (i < 80) and digit(str[i]) do i := i + 1; while (i < 80) and (str[i] = ' ') do i := i + 1; if i <> 80 then prterr(econv) end; { get integer from basic string } function getbval(var str: bstring80): integer; var i, v: integer; begin i := 1; while (i <= str.len) and (str.str[i] = ' ') do i := i + 1; { skip spaces } if not digit(str.str[i]) then prterr(einte); { number not present } v := 0; { clear result } while (i <= str.len) and digit(str.str[i]) do begin { parse digit } v := v*10+ord(str.str[i])-ord('0'); { scale, convert and add in digit } i := i+1 { next character } end; while (i <= str.len) and (str.str[i] = ' ') do i := i + 1; if i <= str.len then prterr(econv); getbval := v { return result } end; { place integer to string } procedure putbval(var str: bstring80; v: integer); var p: integer; { power holder } i: integer; { string index } begin str.len := 0; { clear result string } p := 10000; { set maximum power } i := 1; { set 1st character } if v < 0 then begin { negative } str.str[i] := '-'; { place minus sign } i := i + 1; { next character } v := -v { negate number } end; while p <> 0 do begin { fit powers } str.str[i] := chr(v div p+ord('0')); { place digit } if str.str[1] = '-' then begin { negative } if (str.str[2] <> '0') or (p = 1) then i := i + 1; { next digit } end else { positive } if (str.str[1] <> '0') or (p = 1) then i := i + 1; { next digit } v := v mod p; { remove from value } p := p div 10 { find next power } end; str.len := i-1 { set length of string } end; { print basic string } procedure prtbstr(var bstr: bstring80); var i: integer; begin for i := 1 to bstr.len do write(bstr.str[i]); end; { input basic string } procedure inpbstr(var bstr: bstring80); var i: integer; begin for i := 1 to 80 do bstr.str[i] := ' '; i := 1; while (i < 80) and not eoln do begin read(bstr.str[i]); i := i + 1 end; if (i > 80) and not eoln then prterr(eiovf); readln; bstr.len := i end; { concatenate basic strings } procedure cat(var bstra, bstrb: bstring80); var i: integer; { index for string } begin if (bstra.len + bstrb.len) > 80 then prterr(estrovf); { string overflow } { copy source after destination } for i := 1 to bstrb.len do bstra.str[bstra.len+i] := bstrb.str[i]; bstra.len := bstra.len + bstrb.len { set new length } end; { check stack items equal } function chkequ : boolean; begin if (temp[top].typ <> tint) or (temp[top - 1].typ <> tint) then prterr(ewtyp); chkequ := temp[top - 1].int = temp[top].int end; { check stack items less than } function chkltn: boolean; begin if (temp[top].typ <> tint) or (temp[top - 1].typ <> tint) then prterr(ewtyp); chkltn := temp[top - 1].int < temp[top].int end; { check stack items greater than } function chkgtn: boolean; begin if (temp[top].typ <> tint) or (temp[top - 1].typ <> tint) then prterr(ewtyp); chkgtn := temp[top - 1].int > temp[top].int end; { set tos true } procedure settrue; begin temp[top].typ := tint; temp[top].int := 1 end; { set tos false } procedure setfalse; begin temp[top].typ := tint; temp[top].int := 0 end; { clear program store } procedure clear; var x, y: integer; c: char; begin for x := 1 to maxpgm do for y := 1 to 80 do prgm[x][y] := ' '; for c := 'a' to 'z' do strs[c].len := 0; for c := 'a' to 'z' do ints[c] := 0; prgmc := 0; linec := 1; top := 1 end; { clear variable store } procedure clrvar; var c: char; begin for c := 'a' to 'z' do strs[c].len := 0; for c := 'a' to 'z' do ints[c] := 0; prgmc := 0; linec := 1; top := 1 end; { execute string } procedure exec; label 1; { exit procedure } var c: char; { execute statement } procedure stat; var x, y: integer; c: char; s: string80; b: boolean; { parse expression } procedure expr; { parse simple expression } procedure sexpr; { parse term } procedure term; { parse factor } procedure factor; var i: integer; c: char; begin { factor } skpspc; c := chkchr; { save starting character } if chknxt('(') then begin expr; if not chknxt(')') then prterr(erpe) end else if chknxt(chr(cadd)) then begin factor; if temp[top].typ <> tint then prterr(ewtyp) end else if chknxt(chr(csub)) then begin factor; if temp[top].typ <> tint then prterr(ewtyp); temp[top].int := - temp[top].int end else if chknxt('"') then begin top := top + 1; if top > maxstk then prterr(eexc); temp[top].typ := tstr; i := 1; while (i <= 80) and (chkchr <> '"') do begin temp[top].bstr.str[i] := getchr; i := i + 1 end; if not chknxt('"') then prterr(emqu); temp[top].bstr.len := i - 1 end else if digit(chkchr) then begin top := top + 1; if top > maxstk then prterr(eexc); temp[top].typ := tint; temp[top].int := getint end else if alpha(chkchr) then begin top := top + 1; if top > maxstk then prterr(eexc); c := getvar; if chknxt('$') then begin temp[top].typ := tstr; temp[top].bstr := strs[c] end else begin temp[top].typ := tint; temp[top].int := ints[c] end end else if chknxt(chr(cleft)) or chknxt(chr(cright)) or chknxt(chr(cmid)) then begin { left$, right$ } skpspc; { skip spaces } if not chknxt('(') then prterr(elpe); { '(' expected } expr; { parse expression } if temp[top].typ <> tstr then prterr(estre); { string expected } skpspc; { skip spaces } if not chknxt(',') then prterr(ecmaexp); { ',' expected } expr; { parse expression } if temp[top].typ <> tint then prterr(einte); { integer expected } skpspc; { skip spaces } if c <> chr(cmid) then begin { left$ or right$ } if not chknxt(')') then prterr(erpe); { ')' expected } if temp[top].int > temp[top-1].bstr.len then prterr(estrinx); if c = chr(cright) then { right$ } for i := 1 to temp[top].int do { move string left } temp[top-1].bstr.str[i] := temp[top-1].bstr.str[i+temp[top-1].bstr.len-temp[top].int]; temp[top-1].bstr.len := temp[top].int; { set new length left } top := top-1 { clean stack } end else begin { mid$ } if not chknxt(',') then prterr(ecmaexp); { ',' expected } expr; { parse end expression } if temp[top].typ <> tint then prterr(einte); { integer expected } skpspc; { skip spaces } if not chknxt(')') then prterr(erpe); { ')' expected } { check requested length > string length } if temp[top].int+temp[top-1].int-1 > temp[top-2].bstr.len then prterr(estrinx); for i := 1 to temp[top].int do { move string left } temp[top-2].bstr.str[i] := temp[top-2].bstr.str[i+temp[top-1].int-1]; temp[top-2].bstr.len := temp[top].int; { set new length left } top := top-2 { clean stack } end end else if chknxt(chr(cchr)) then begin { chr } if not chknxt('(') then prterr(elpe); { '(' expected } expr; { parse expression } if temp[top].typ <> tstr then prterr(estre); { string expected } skpspc; { skip spaces } if not chknxt(')') then prterr(erpe); { ')' expected } if temp[top].bstr.len < 1 then prterr(estrinx); { check valid } c := temp[top].bstr.str[1]; { get the 1st character } temp[top].typ := tint; { change to integer } temp[top].int := ord(c) { place result } end else if chknxt(chr(cval)) then begin { val } if not chknxt('(') then prterr(elpe); { '(' expected } expr; { parse expression } if temp[top].typ <> tstr then prterr(estre); { string expected } skpspc; { skip spaces } if not chknxt(')') then prterr(erpe); { ')' expected } i := getbval(temp[top].bstr); { get string value } temp[top].typ := tint; { change to integer } temp[top].int := i { place result } end else if chknxt(chr(cstr)) then begin { str$ } if not chknxt('(') then prterr(elpe); { '(' expected } expr; { parse expression } if temp[top].typ <> tint then prterr(einte); { integer expected } skpspc; { skip spaces } if not chknxt(')') then prterr(erpe); { ')' expected } i := temp[top].int; { get value } temp[top].typ := tstr; { change to string } putbval(temp[top].bstr, i) { place value in ascii } end else prterr(eifact) end; { factor } begin { term } factor; skpspc; while ord(chkchr) in [cmult, cdiv, cmod] do begin case ord(getchr) of { tolken } cmult: begin { * } factor; if (temp[top].typ <> tint) or (temp[top - 1].typ <> tint) then prterr(ewtyp); temp[top - 1].int := temp[top - 1].int * temp[top].int; top := top - 1 end; cdiv: begin { / } factor; if (temp[top].typ <> tint) or (temp[top - 1].typ <> tint) then prterr(ewtyp); temp[top - 1].int := temp[top - 1].int div temp[top].int; top := top - 1 end; cmod: begin { mod } factor; if (temp[top].typ <> tint) or (temp[top - 1].typ <> tint) then prterr(ewtyp); temp[top - 1].int := temp[top - 1].int mod temp[top].int; top := top - 1 end end; skpspc { skip spaces } end end; { term } begin { sexpr } term; skpspc; while ord(chkchr) in [cadd, csub] do begin case ord(getchr) of { tolken } cadd: begin term; if temp[top].typ = tstr then begin if temp[top - 1].typ <> tstr then prterr(estyp); cat(temp[top - 1].bstr, temp[top].bstr); top := top - 1 end else begin if temp[top - 1].typ <> tint then prterr(estyp); temp[top - 1].int := temp[top - 1].int + temp[top].int; top := top - 1; end end; csub: begin { - } term; if (temp[top].typ <> tint) or (temp[top - 1].typ <> tint) then prterr(ewtyp); temp[top - 1].int := temp[top - 1].int - temp[top].int; top := top - 1 end end; skpspc { skip spaces } end end; { sexpr } begin { expr } sexpr; { parse simple expression } skpspc; { skip spaces } while ord(chkchr) in [cequ, cnequ, cltn, cgtn, clequ, cgequ] do begin case ord(getchr) of { tolken } cequ: begin sexpr; if chkequ then begin top := top - 1; settrue end else begin top := top - 1; setfalse end end; cnequ: begin sexpr; if chkequ then begin top := top - 1; setfalse end else begin top := top - 1; settrue end end; cltn: begin sexpr; if chkltn then begin top := top - 1; settrue end else begin top := top - 1; setfalse end end; cgtn: begin sexpr; if chkgtn then begin top := top - 1; settrue end else begin top := top - 1; setfalse end end; clequ: begin sexpr; if chkgtn then begin top := top - 1; setfalse end else begin top := top - 1; settrue end end; cgequ: begin sexpr; if chkltn then begin top := top - 1; setfalse end else begin top := top - 1; settrue end end end; skpspc { skip spaces } end end; { expr } { process "let" function } procedure let; begin skpspc; c := getvar; if chknxt('$') then begin skpspc; if not chknxt(chr(cequ)) then prterr(eeque); expr; if temp[top].typ <> tstr then prterr(estyp); strs[c] := temp[top].bstr; top := top - 1 end else begin skpspc; if not chknxt(chr(cequ)) then prterr(eeque); expr; if temp[top].typ <> tint then prterr(estyp); ints[c] := temp[top].int; top := top - 1 end end; begin { stat } skpspc; if ord(chkchr) < ord(' ') then begin if ord(chkchr) > cbye then prterr(estate); case ord(getchr) of { statement } cinput: begin skpspc; c := getvar; if chknxt('$') then inpbstr(strs[c]) else begin inpstr(s); ints[c] := getval(s) end end; cprint: begin repeat { list items } expr; if temp[top].typ = tstr then prtbstr(temp[top].bstr) else write(temp[top].int); top := top - 1; skpspc until not chknxt(','); { until not ',' } if not chknxt(';') then writeln end; cgoto: begin prgmc := schlab(getint); goto 1 end; cif: begin expr; if temp[top].typ <> tint then prterr(eexmi); if temp[top].int = 0 then begin top := top - 1; { go next line } if prgmc > 0 then prgmc := prgmc + 1; goto 1 end; top := top - 1; b := chknxt(chr(cthen)); stat end; crem: begin if prgmc > 0 then prgmc := prgmc + 1; { go next line } goto 1 { exit line executive } end; cstop: goto 88; crun: begin clrvar; prgmc := 1; goto 1 end; clist: begin x := 1; { set default list swath } y := maxpgm; if not chksend then begin { list swath is specified } x := schlab(getint); skpspc; { check if end line is specified } if chknxt(',') then y := schlab(getint) end; for x := x to y do { print specified lines } if not null(prgm[x]) then { line exists in buffer } prtlin(prgm[x]) { print } end; cnew: begin clear; goto 88 end; clet: let; cbye: goto 99 end end else let { default let } end; { stat } begin { exec } linec := 1; while digit(chkchr) do c := getchr; { skip label } repeat stat until getchr <> ':'; skpspc; if not chkend then prterr(eedlexp); { should be at line end } if prgmc > 0 then prgmc := prgmc + 1; 1: end; { exec } begin { executive } clear; { initalize keys } keywd[cinput] := 'input '; keywd[cprint] := 'print '; keywd[cgoto] := 'goto '; keywd[cif] := 'if '; keywd[crem] := 'rem '; keywd[cstop] := 'stop '; keywd[crun] := 'run '; keywd[clist] := 'list '; keywd[cnew] := 'new '; keywd[clet] := 'let '; keywd[cbye] := 'bye '; keywd[clequ] := '<= '; keywd[cgequ] := '>= '; keywd[cequ] := '= '; keywd[cnequ] := '<> '; keywd[cltn] := '< '; keywd[cgtn] := '> '; keywd[cadd] := '+ '; keywd[csub] := '- '; keywd[cmult] := '* '; keywd[cdiv] := '/ '; keywd[cmod] := 'mod '; keywd[cleft] := 'left$ '; keywd[cright] := 'right$ '; keywd[cmid] := 'mid$ '; keywd[cthen] := 'then '; keywd[cstr] := 'str$ '; keywd[cval] := 'val '; keywd[cchr] := 'chr '; writeln; writeln('Tiny basic interpreter vs. 0.1 Copyright (C) 1994 S. A. Moore'); writeln; 88: while true do begin writeln('Ready'); 77: prgmc := 0; linec := 1; top := 0; { get user lines until non-blank } repeat inpstr(prgm[0]) until not null(prgm[0]); keycom(prgm[0]); if lint(prgm[0]) > 0 then begin enter(prgm[0]); goto 77 end else repeat exec; if (prgmc > maxpgm) then prgmc := 0 else if null(prgm[prgmc]) then prgmc := 0 until prgmc = 0 end; 99: writeln end.'
It compiles down into PASM.
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This is as fast as you can go. No matter what code you write in.
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The Simple IDE is a joke!!!
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C , C+++ , C what ever needs so much user input. I just don't like to type that much.
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Why Parallax bailed on Basic is beyond me????....This is what founded the company.
Are we almost done second-guessing each other here, or is this thread headed for Whit's "Most Viewed Thread" thread?
I think this young thread definitely wins the "rate of viewing *& commenting" award anyway.
Regarding the biggest downside of C,
there are some rather daunting formalities that the plain vanila beginner might become dismayed with.
A. The Preprocessor
B. Syntax Checking
C. Object Code generation
D. Linking
All these steps have good reasons to exist. But for a begineer, there are more ways to mess up.
In the beginning, too much formality will often chase away otherwise able learners. So why bother to load up the new student until they have ambitions for greater things.
Heater may know a lot, but he certainly doesn't think like an educator. And when someone asked why Basic or C, I strongly suspect they are looking to begin learning --- not to add to their professional development.
PropBasic might just appeal to the many users that have felt unable to grasp SPIN and Object Oriented Programing. SPIN is a great language, but it has scared off a lot of naive-but-willing-to-learn new users.
So this is wonderful as Parallax is filling in the gaps in a solid pathway to learning towards becoming a pro.
:-)
Personally, I will never look at Pascal, and Lisp drove me crazy when I attempted to do so. They do have their uses, but either in history or advance study.
C is a much more powerful language but for what the average person will do BASIC gets the job done.
C is also a lot more abstract and it lacks many of the convenience and safety features that BASIC has such as error checking and garbage collection.
Careful where you stick that C pointer or you might crash your system.
Loopy, I found Spin to very similar with PBASIC though there are some differences. I learned PASCAL after having learned BASIC and it made learning C a lot easier.
Now that is a step to far. One should not speak ill of the dead. ALGOL was a wonderful thing. The first language to properly express, indeed define, structured programming as we know it today. Even modern BASICS follow in the footsteps of ALGOL with their if/else, while, for, do, named functions, data structures etc, etc, etc.
I'm not sure which ALGOL you were shown that was made ugly for you with &[]\">>> etc. I learned ALGOL as my third programming language and I don't recall having any such trouble. Mind you I don't remember much. I seem to recall it looked like this example for wikipedea:
[B]procedure[/B] Absmax(a) Size:(n, m) Result:(y) Subscripts:(i, k); [B]value[/B] n, m; [B]array[/B] a; [B]integer[/B] n, m, i, k;[B] real[/B] y; [B]comment[/B] The absolute greatest element of the matrix a, of size n by m is transferred to y, and the subscripts of this element to i and k; [B]begin[/B] [B]integer[/B] p, q; y := 0; i := k := 1; [B]for[/B] p := 1 [B]step[/B] 1 [B]until[/B] n [B]do[/B] [B]for[/B] q := 1 [B]step[/B] 1 [B]until[/B] m do [B]if[/B] abs(a[p, q]) > y [B]then[/B] [B]begin[/B] y := abs(a[p, q]); i := p; k := q [B]end[/B] [B]end[/B] [B]Absmax[/B]A thing of beauty.1. Why it has : in front of =
2. Why some lines end with ;, while others - not
3. "for p := 1 step 1 until n do" - what this line does, it is not possible to understand from human knowing of english language, while basic is much closer to "real" language in such constructions.