Syntax highlighting categories #21

hackerb9 · 2022-10-26T16:39:57Z

What are the conventions for syntax highlighting of BASIC code? While working on issue #20 (derived modes), I have run into a problem that I do not know the meaning of groupings like basic-builtin-regexp and basic-keyword-regexp.

If there is a "typical" convention, it would be helpful to have it in the comments in basic-mode.el. If there is not, and I suspect there isn't yet, it may be good to see what others have done and look at what makes sense.

Note that not all of the categories are confusing. Comments, constants, strings, and so on are self-explanatory. The ones that I'd like to get nailed down are:

functions: this one seems to be for the keywords (like SIN()) which return a value. The definition of it makes sense, but there is some question about whether things like PEEK() and TIME$ belong. And is this distinction even helpful to a programmer?
keywords: currently appears to be the bones which lay the structure of a BASIC program. Includes control-flow and function/subroutine definitions. There are few confusing entries, though, like AS and RANDOMIZE. And wouldn't it make more sense for data type declarations like DEFINT to be highlighted as a type?
builtins: appears to be the meat: all the other statements which do something. PRINT, PEEK, POKE, etc. But there are several counter examples to that idea. DATA and LET seem to be more structural. AND, MOD, NOT, OR, and XOR are operators and I would have expected them to be highlighted differently.

The text was updated successfully, but these errors were encountered:

hackerb9 · 2022-10-26T16:43:40Z

Possibly of use: I see that the QuickBasic manual breaks its statements into the following groups:

Control-Flow Statements
Statements Used in BASIC Procedures
Standard I/O Statements
File I/O Statements
String-Processing Statements and Functions
Graphics Statements and Functions
Trapping Statements and Functions

I do not know if these categories overlap or if they have any relationship to what is actually used in syntax highlighting systems. I will say that I think it is a very good feature that basic-mode makes control-flow distinct.

Update: after reading through that chapter, I think it actually contains some very useful divisions for syntax highlighting and it is not too different from how basic-mode currently works. In particular, Control-Flow (GOTO, IF...THEN, FOR..NEXT) is fundamental to BASIC programmers and is already prominently shown.

Less common, but perhaps even more important to shine a spotlight on are the Trapping Statements (ON ERR GOTO...) which can change a program's flow of control asynchronously. (For example, ON COM GOSUB is used on the Tandy 200 to run a BASIC routine when data comes in on the serial port.) Currently traps are shown the same as control-flow in basic-mode, but I suggest that they ought to be even more vivid.

Statements Used in Procedures (SUB, FUNCTION, DEF FN) are also currently shown in the same face as Control-Flow, but if there are any spare font-lock categories left, it may look better if they were subtly different.

I do not have problem with mushing together Standard I/O and File I/O and Graphics Statements, but I'm not opposed to keeping them separate as the QuickBasic manual has them either. String-Processing Functions do make some sense to show with a slight variation from normal statements, but I do not know if it is worth going out of the way to do.

hackerb9 · 2022-10-26T17:39:01Z

Samples of other syntax highlighting for BASIC:

Github GFM

Github's MarkDown attempts to syntax highlight fenced code blocks. For example:

```BASIC
0 DEFINT X=32768, Y=RND(-1)  ' SALT
10 PRINT "HELLO, WORLD! "; TIME$; 
20 Y=(31*Y+PEEK(X)) MOD 257: REM PRIME HASH
30 X=X+1: GOSUB 10
```

Becomes,

0 DEFINT X=32768, Y=RND(-1)  ' SALT
10 PRINT "HELLO, WORLD! "; TIME$; 
20 Y=(31*Y+PEEK(X)) MOD 257: REM PRIME HASH
30 X=X+1: GOSUB 10

https://docs.github.com/en/get-started/writing-on-github/working-with-advanced-formatting/creating-and-highlighting-code-blocks#syntax-highlighting

We use Linguist to perform language detection and to select third-party grammars for syntax highlighting. You can find out which keywords are valid in the languages YAML file.

Telnet23's language-basic

Github actually relies on telnet23's language-basic syntax highlighting. Like basic-mode.el, it properly marks control-flow as being important. Unfortunately, the way Github has used it, control-flow and operators are both shown in red, so in practice, control-flow is not distinct.

One feature it has that basic-mode.el should ~~steal~~ acquire is highlighting line numbers when they are referenced by statements like GOTO 10 in the line number color.

The main categories appear to be BASIC's typical functions, statements, and operators, but interestingly, it separates string functions from other functions. I suppose the reasoning is that it shows the type the function is returning. Is that an idea that would be helpful to programmers?

The regexps are succinctly defined in .CSON format:

Click to see the regexps

scopeName: 'source.basic'
name: 'BASIC'
fileTypes: [ 'bas' ]
patterns: [
  {
    # line number definition
    match: '^\\s*\\d+'
    name: 'entity.name.tag.basic'
  }
  {
    # line number reference
    match: '\\b((?i)THEN|ELSE|GO\\s*TO|GOSUB)\\s*(\\d+)'
    captures:
      1: name: 'keyword.control.basic'
      2: name: 'entity.name.tag.basic'
  }
  {
    # number
    match: '\\b(?:\\d\\.|\\d+\\.\\d+|\\.\\d+|\\d+)(?:[Ee][-+]?\\d+)?\\b'
    name: 'constant.numeric.basic'
  }
  {
    # string
    match: '"[^"]*"'
    name: 'string.quoted.double.basic'
  }
  {
    # comment
    match: '(?i:REM.*)'
    name: 'comment.line.basic'
  }
  {
    # flow control statement
    match: '\\b(?i:FOR|TO|NEXT|IF|THEN|ELSE|GO\\s*TO|GOSUB|RETURN)\\b'
    name: 'keyword.control.basic'
  }
  {
    # other statement
    match: '\\b(?i:\\?|\\&|\\!|\'|ABSOLUTE|ACCESS|AS|BASE|BEEP|BLOAD|BSAVE|CALL|CASE|CHAIN|CHDIR|CIRCLE|CLEAR|CLOSE|CLS|COLOR|COM|COMMON|CONST|DATA|DECLARE|DEF|DEFDBL|DEFINT|DEFLNG|DEFSNG|DEFSTR|DIM|DO|DRAW|END|ENVIRON|ERASE|ERROR|EXIT|FIELD|FILES|FUNCTION|GET|HOME|IF|INPUT|INPUT#|IOCTL|KEY|KILL|LET|LINE|LOCATE|LOCK|LOOP|LPRINT|LSET|MKDIR|NAME|NEW|ON|OPEN|OPTION|OUT|PAINT|PALETTE|PCLEAR0|PCLEAR1|PCOPY|PEN|PLAY|PMAP|PMODE0|POKE|PRESET|PRINT|PRINT#|PSET|PUT|RANDOMIZE|READ|REDIM|REM|RESET|RESTORE|RESUME|RMDIR|RSET|RUN|SCREEN|SEEK|SELECT|SHARED|SHELL|SLEEP|SOUND|SOUNDRND|STATIC|STOP|STRIG|SUB|SWAP|SYSTEM|TIMER|TROFF|TRON|TYPE|UNLOCK|USING|VIEW|WAIT|WEND|WHILE|WINDOW|WRITE)\\b'
    name: 'entity.name.type.basic'
  }
  {
    # string function
    match: '\\b(?i:BIN|CHR|COMMAND|DATE|ENVIRON|ERDEV|HEX|INKEY|INPUT|IOCTL|LAFT|LCASES|LEFT|LTRIM|MID|MKD|MKDMBF|MKI|MKL|MKS|MKSMBF|OCT|RIGHT|RTRIM|SPACE|SPC|STR|STRING|TAB|TIME|UCASE|UPS|VARPTR)\\$'
    name: 'entity.name.function.basic'
  }
  {
    # non-string function
    match: '\\b(?i:ABS|ASC|ATN|BRK|CDBL|CINT|CLNG|COS|CSNG|CSRLIN|CTL|CVD|CVDMBF|CVI|CVL|CVS|CVSMBF|D2R|EOF|ERDEV|ERL|ERR|EXP|FILEATTR|FIX|FRE|FREEFILE|HEIGHT|INP|INSTR|INT|ITM|LBOUND|LEN|LG|LIN|LN|LOC|LOF|LOG|LOG10|LPOS|NINT|NUM|PEEK|PEN|POINT|POS|R2D|REC|RND|SADD|SCREEN|SEEK|SETMEM|SGN|SIN|SPA|SPC|SQR|SQRT|STICK|STRIG|SYS|TAB|TAN|TIM|TIMER|TYP|UBOUND|VAL|VALPTR|VALSEG|VARPTR|VARSEG|WIDTH)\\b'
    name: 'entity.name.function.basic'
  }
#  {
#    # other function
#    match: '\\b(\\w+[\\$%!]?)\\('
#    captures:
#      1: name: 'entity.name.function.basic'
#  }
  {
    # operator
    match: '\\^|\\+|-|\\*\\*|\\*|/|=|<>|<=|=<|>=|=>|<|>|\\b(?i:MOD|NOT|AND|OR)\\b'
    name: 'keyword.operator.basic'
  }
]

KATE editor

https://github.com/zhangwinston/syntax-highlighting/blob/master/data/syntax/freebasic.xml

hackerb9 · 2022-10-26T19:52:32Z

Just for reference, here are the categories into which Bill Crider's “BASIC Programming Conversion” puts the reserved words from several dialects of BASIC. Actually, "tags" would be a better description, as each word can fit in multiple boxes.

INPUT
1. Human: Keyboard, Joystick, Paddle, Light Pen
  1. CMD
  2. GET
  3. GET#
  4. IN#
  5. INKEY$
  6. INPUT
  7. INPUT LINE
  8. INPUT#
  9. INPUT$
  10. JOYSTK
  11. KEY
  12. KEY$
  13. LINE INPUT
  14. LINE INPUT#
  15. PDL
  16. PEEK
  17. PEN
  18. POKE (for input?)
  19. PR#
  20. READ
  21. READ#
  22. STICK
  23. STRIG
2. Storage: Cassette, Sequential/Random file access, Disk
  1. APPEND
  2. AUDIO
  3. B-A:
  4. B-F:
  5. B-P:
  6. B-R:
  7. B-W:
  8. BACKUP
  9. BLOAD
  10. BLOCK-ALLOCATE:
  11. BLOCK-EXECUTE:
  12. BLOCK-FREE:
  13. BLOCK-READ:
  14. BLOCK-WRITE:
  15. BSAVE
  16. BUFFER-POINTER
  17. CATALOG
  18. CHAIN
  19. CHDIR
  20. CLOAD
  21. CLOADM
  22. CLOSE
  23. CMD
  24. COPY
  25. CSAVE
  26. CSAVEM
  27. DCLOSE
  28. DELETE
  29. DIR
  30. DIRECTORY
  31. DLOAD
  32. DLOADM
  33. DOPEN
  34. DRIVE
  35. DSAVE
  36. DSKI$
  37. DSKINI
  38. DSKO$
  39. EOF
  40. ERASE
  41. FIELD
  42. FILE
  43. FILES
  44. FORMAT
  45. FRE
  46. FREE
  47. GET
  48. GET#
  49. IN#
  50. INP
  51. INPUT
  52. INPUT #
  53. INPUT$
  54. KILL
  55. LINE INPUT
  56. LINE INPUT#
  57. LOAD
  58. LOADM
  59. LOF
  60. LPOS
  61. M-E:
  62. M-R:
  63. M-W:
  64. MEMORY-EXECUTE:
  65. MEMORY-READ:
  66. MEMORY-WRITE:
  67. MERGE
  68. MKDIR
  69. MOTOR
  70. NAME
  71. NEW
  72. OPEN
  73. OUT
  74. OUTPUT
  75. POINTER
  76. PR #
  77. PRINT
  78. PRINT #
  79. PRINT #USING
  80. PRINT USING
  81. PUT
  82. PUT#
  83. READ
  84. READ#
  85. RECALL
  86. RECORD
  87. RESTORE
  88. RMDIR
  89. RUN
  90. SAVE
  91. SAVEM
  92. SCRATCH
  93. SHLOAD
  94. SKIPF
  95. ST
  96. STATUS
  97. STORE
  98. UNLOAD
  99. WRITE
  100. WRITE#
3. External Input: Display, Serial/Modem, Printer, A/D Converter
  1. COM
  2. CMD
  3. CSRLIN
  4. IN#
  5. IN
  6. INP
  7. LPOS
  8. PEEK
  9. POINT
  10. POSN
  11. PPOINT
  12. ST
  13. STATUS
  14. WAIT
  15. SCREEN
PROCESSING
1. Program Flow
  1. AUTO
  2. BUFFER-POINTER
  3. CHAIN
  4. CHDIR
  5. CMD
  6. DATA
  7. DELETE
  8. ELSE
  9. END
  10. ERASE
  11. ERL
  12. ERR
  13. ERROR
  14. ERRS$
  15. FOR
  16. GOSUB
  17. GOTO
  18. IF
  19. IF-THEN
  20. IF-THEN-ELSE
  21. KILL
  22. LIST
  23. LLIST
  24. M-E
  25. ON ERR
  26. POINTER
  27. REM
  28. REN
  29. RENAME
  30. RENUM
  31. RENUMBER
  32. RESTORE
  33. RESUME
  34. MEMORY-EXECUTE
  35. RESUME NEXT
  36. RETURN
  37. RMDIR
  38. MKDIR
  39. NEXT
  40. NOTRACE
  41. ON ERR GOTO
  42. ON ERROR GOTO
  43. RUN
  44. SCRATCH
  45. SHELL
  46. SKIPF
  47. SPEED=
  48. STOP
  49. THEN
  50. TO
  51. TRACE OFF
  52. TRACE ON
  53. TRACE
  54. TROFF
  55. TRON
  56. WAIT
  57. WEND
  58. WHILE
2. Functions
  1. ABS
  2. ASC
  3. ATN
  4. CDBL
  5. CHR$
  6. CINT
  7. COS
  8. CSRLIN
  9. CVD
  10. CVI
  11. CVN
  12. CVS
  13. EOF
  14. ERL
  15. ERR
  16. ERRS$
  17. EXP
  18. FIX
  19. FRE
  20. HEXS
  21. INKEY$
  22. INP
  23. INPUT$
  24. JOYSTK
  25. LEFT$
  26. LOC
  27. LOF
  28. LOG
  29. LPOS
  30. M-R:
  31. MEM
  32. MEMORY-READ:
  33. MID$
  34. MKD$
  35. MKI$
  36. MKN$
  37. MKS$
  38. OCT$
  39. PDL
  40. PEEK
  41. PEN
  42. POINT
  43. POS
  44. PPOINT
  45. RIGHT$
  46. RND
  47. ROW
  48. SCREEN
  49. SGN
  50. SQR
  51. STRIG
  52. TIME$
  53. SIN
  54. SPACE$
  55. STATUS
  56. STICK
  57. STRING$
  58. TANVAL
  59. VARPTR
  60. SPC(
  61. STR$
  62. TI$
  63. VARPTR$
3. Operators
  1. ^ Exponentiation
  2. - Negation
  3. * Multiplication
  4. / Floating-Point Division
  5. \ Integer Division
  6. MOD Modulo Arithmetic
  7. + Addition
  8. - Subtraction
  9. = Equality
  10. < Less Than
  11. > Greater Than
  12. NOT
  13. AND
  14. OR
  15. XOR
  16. EQV
  17. IMP
4. Data Types: Constants, Variables, Strings, Numerics, Arrays
  1. CDBL
  2. CHR$
  3. CINT
  4. COMMON
  5. CONCAT
  6. CSNG
  7. CVD
  8. CVI
  9. CVN
  10. CVS
  11. DATA
  12. DEFDBL
  13. DEFFN
  14. DEFINT
  15. DEFSNG
  16. DEFSTR
  17. DIM
  18. FIX
  19. HEX$
  20. INT
  21. LET
  22. MKD$
  23. MKI$
  24. MKN$
  25. MKS$
  26. OCT$
  27. OPTION BASE
  28. STR$
  29. STRING$
  30. SWAP
  31. VAL
  32. VARPTR
  33. VARPTR$
5. Machine & Memory Interface
  1. B-A:
  2. B-F:
  3. B-P:
  4. B-R:
  5. B-W:
  6. BLOAD
  7. BLOCK-ALLOCATE:
  8. BLOCK-EXECUTE:
  9. BLOCK-FREE:
  10. BLOCK-READ:
  11. BLOCK-WRITE:
  12. BSAVE
  13. BUFFER-POINTER:
  14. CALL
  15. DEF SEG
  16. FRE
  17. HIMEM:
  18. INP
  19. LOADM
  20. LOMEM:
  21. M-E:
  22. M-R:
  23. M-W:
  24. MEM
  25. MEMORY-EXECUTE:
  26. MEMORY-READ:
  27. MEMORY-WRITE:
  28. OUT
  29. PCLEAR
  30. PCLS
  31. PCOPY
  32. PEEK
  33. PMODE
  34. POKE
  35. POP
  36. PR #
  37. SAVEM
  38. SHLOAD
  39. SPEED=
  40. STATUS
  41. SYS
  42. SYSTEM
  43. UNLOAD
  44. USER
  45. USR
  46. VARPTR
  47. VARPTR$
OUTPUT
1. Display output
  1. CIRCLE
  2. CLS
  3. CMD
  4. COLOR
  5. COLOR=
  6. CSRLIN
  7. DRAW
  8. DRAWTO
  9. FLASH
  10. GET
  11. GR
  12. HCOLOR
  13. HCOLOR=
  14. HGR
  15. HGR2
  16. HLIN
  17. HLIN-AT
  18. HPLOT
  19. HTAB
  20. INVERSE
  21. KEY
  22. LINE
  23. LOCATE
  24. NORMAL
  25. PAGE
  26. PAINT
  27. PALETTE
  28. PALETTE USING
  29. PCLEAR
  30. PCLS
  31. PCOPY
  32. PEEK
  33. PEN
  34. PLOT
  35. PMAP
  36. PMODE
  37. POINT
  38. POINTER
  39. POKE
  40. PPOINT
  41. PR #
  42. PRESET
  43. PRINT
  44. PRINT #
  45. PRINT #USING
  46. PRINT @
  47. PRINT AT
  48. PRINT USING
  49. PSET
  50. PUT
  51. RESET
  52. ROT=
  53. SCALE
  54. SCALE=
  55. SCREEN
  56. SCRN(
  57. SET
  58. SHLOAD
  59. VIEW
  60. VLIN
  61. VLIN-AT
  62. VPOS
  63. VTAB
  64. WIDTH
  65. WINDOW
  66. WRITE
  67. WRITE #
  68. XDRAW
  69. XPLOT
2. Sound
  1. AUDIO
  2. BEEP
  3. MOTOR
  4. NOISE
  5. PEEK
  6. PLAY
  7. POKE
  8. SOUND
3. Printer
  1. CMD
  2. LLIST
  3. LPOS
  4. LPRINT
  5. LPRINT USING
  6. POSN
  7. PR #
  8. PRINT
  9. PRINT @
  10. PRINT #
  11. PRINT #USING
  12. PRINT USING
  13. ST
  14. STATUS
  15. TAB
  16. TAB(
  17. WRITE
  18. WRITE#
4. Storage output
  1. APPEND
  2. B-A:
  3. B-F:
  4. B-P:
  5. B-R:
  6. B-W:
  7. BACKUP
  8. BLOCK-READ:
  9. BLOCK-WRITE:
  10. BLOCK-ALLOCATE:
  11. BLOCK-EXECUTE:
  12. BLOCK-FREE:
  13. BUFFER-POINTER
  14. BSAVE
  15. CATALOG
  16. CHDIR
  17. CLOSE
  18. DSKI$
  19. DSKO$
  20. PRINT USING
  21. PUT
  22. CMD
  23. COLLECT
  24. COPY
  25. CSAVE
  26. CSAVEM
  27. DCLOSE
  28. DELETE
  29. DIR
  30. DIRECTORY
  31. DOPEN
  32. DRIVE
  33. DSAVE
  34. DSKINI
  35. ERASE
  36. FIELD
  37. FILES
  38. KILL
  39. LOF
  40. MKDIR
  41. MOTOR
  42. OPEN
  43. OUTPUT
  44. PR #
  45. PRINT
  46. PUT #
  47. PRINT #
  48. PRINT #USING
  49. RENAME
  50. RMDIR
  51. SAVE
  52. SAVEM
  53. SCRATCH
  54. SYSTEM
  55. TAB
  56. TAB(
  57. STORE
  58. UNLOAD
  59. WRITE
  60. WRITE#
5. External Communications
  1. AUDIO
  2. CMD
  3. COM
  4. MOTOR
  5. OFF
  6. ON
  7. OUT
  8. PEEK
  9. POKE
  10. PR #
  11. WAIT

Crider says that he is covering BASIC for "Apple, IBM PC, IBM PCjr, Commodore 64, TRS-80 Model III, and TRS-80 Color Computer". However, I noticed that his list of all 551 reserved words one should avoid using in identifiers as they are defined in one BASIC or another actually includes more keywords than were listed in the categories above. They appear to be from Atari BASIC (e.g., PTRIG) and Tektronix 4051 Graphic System BASIC Language (e.g., BAPPEN).

ABS
ACS
ACSD
ACSG
ADR
AND
APPEND
ARCOS
ARCSIN
ARCTAN
ASC
ASCII
ASN
ASND
ASNG
AT
ATAN
ATN
ATND
ATNG
AUDIO
AUTO
AXIS
B-A:
B-F:
B-P:
B-R:
B-W:
BACKUP
BAPPEN
BASE
BEEP
BGET
BLOAD
BLOCK-ALLOCATE:
BLOCK-EXECUTE:
BLOCK-FREE:
BLOCK-READ:
BLOCK-WRITE:
BUFFER-POINTER
BOLD
BPUT
BREAK
BRIGHTNESS
BSAVE
BUTTON
BYE
CALL
CATALOG
CDBL
CH
CHAIN
CHANGE
CHAR
CHAR$
CHARSIZE
CHDIR
CHR
CHR$
CINT
CIRCLE
CLEAR
CLG
CLK$
CLK
CLOAD
CLOADM
CLOCK
CLOG
CLOSE
CLR
CLRDOT
CLS
CMD
CO
CODE
COLLECT
COLOR
COLOR=
COM
COMMON
CON
CONCAT
CONSOLE
CONT
COPY
COS
COSD
COSG
COSH
COUNT
CSAVE
CSAVEM
CSH
CSNG
CSRLIN
CUR
CVD
CVI
CVN
CVS
CVT$%
CVT$F
CVT%$
CVTF$
DASH
DAT
DATA
DATE$
DCLOSE
DEBUG
DEF
DEFDBL
DEFFN
DEFINT
DEF SEG
DEFSNG
DEFSTR
DEFUSR
DEG
DEGREE
DEL
DELETE
DET
DIGITS
DIM
DIR
DIRECTORY
DLOAD
DLOADM
DMS
DOPEN
DOS
DOT
DRAW
DRAWTO
DRIVE
DS
DSAVE
DSKI$
DSKINI
DSKO$
DSP
EDIT
ELSE
END
ENTER
ENVIRON
ENVIRON$
EOF
EQ
EQV
ERASE
ERDEV
ERDEV$
ERL
ERR
ERRL
ERRN
ERROR
ERRS$
EXAM
EXCHANGE
EXEC
EXIT
EXP
EXT
FDIM
FETCH
FGET
FIELD
FIF
FILE
FILES
FILL
FIN
FIND
FINPUT
FIX
FLASH
FLOW
FLT
FMT
FN
FNEND
FONT
FOR
FORMAT
FOUT
FPRINT
FPUT
FRAC
FRE
FREE
FUNTIL
FUZZ
GE
GET
GET#
GIN
GO
GO TO
GOODBYE
GOSUB
GOSUB-OF
GOT
GOTO
GOTO-OF
GR
GRAD
GRAPHICS
GT
HCOLOR
HCOLOR=
HEADER
HEX$
HGR
HGR2
HIMEM:
HLIN
HLIN-AT
HOME
HPLOT
HSCRN
HTAB
IF
IF-GOT
IF-GOTO
IF-LET
IF-THE
IF-THEN
IF-THEN-ELSE
IMAGE
IMP
IN#
INCH
INCHAR
INDEX
INIT
INKEY$
INP
INPUT
INPUT#
INPUT$
INPUT1
INPUTLINE
INSTR
INT
INTER$
INVERSE
IOCTL
IOCTL$
JOYSTK
KEY
KEY$
KILL
LE
LEFT
LEFT$
LEN
LET
LGT
LI
LIN
LINE
LINE INPUT#
LINEINPUT
LINK
LINPUT
LIS
LIST
LLIST
LN
LOAD
LOADM
LOC
LOCATE
LOF
LOG
LOG10
LOGE
LOMEM:
LPOS
LPRINT
LPRINTUSING
LSET
LT
M-E:
M-R:
M-W:
MAN
MARK
MAT *
MAT +
MAT -
MAT =
MAT CON
MAT IDN
MAT INPUT
MAT INV
MAT PRINT
MAT READ
MAT TRN
MAT ZER
MAX
MDD
MEM
MEMORY-EXECUTE:
MEMORY-READ:
MEMORY-WRITE:
MERGE
MID
MID$
MIN
MKD$
MKDIR
MKI$
MKN$
MKS$
MOD
MONITOR
MOTOR
MPY
MTPACK
NAME
NE
NEW
NEX
NEXT
NOFLOW
NOISE
NORMAL
NOT
NOTE
NOTRACE
NULL
NUM
NUM$
OCT$
OFF
OLD
ON
ON ERR GOTO
ON ERROR GOTO
ON-GOSUB
ON-GOT
ON-GOTO
ONERR
OPEN
OPTION
OPTION BASE
OR
OUT
OUTPUT
PADDLE
PAGE
PAINT
PALETTE
PALETTE USING
PAUSE
PCLEAR
PCLS
PCOPY
PDL
PEEK
PEN
PI
PIN
PLAY
PLOT
PMAP
PMODE
POINT
POINTER
POKE
POLL
POP
POS
POSITION
POSN
PPOINT
PR#
PRECISION
PRESET
PRI
PRINT
PRINT #USING
PRINT AT
PRINT USING
PRINT #
PRINT @
PSET
PTR
PTRIG
PUT
PUT#
RAD
RADIAN
RAN
RANDOM
RANDOMIZE
RBYTE
RDRAW
REA
READ
READ#
RECALL
RECORD
REM
REMARK
REN
RENAME
RENUM
RENUMBER
REP
REPEAT$
RES
RESET
RESTORE
RESUME
RESUME NEXT
RET
RETURN
RIGHT
RIGHT$
RMDIR
RMOVE
RND
ROT=
ROTATE
ROW
RSET
RU
RUN
SAVE
SAVEM
SCALE
SCALE=
SCR
SCRATCH
SCREEN
SCRN
SCRN(
SECRET
SEG
SEG$
SET
SETCOLOR
SETDOT
SGET
SGN
SHELL
SHLOAD
SHUT
SIN
SIND
SING
SINH
SKIPF
SLEEP
SNH
SORT
SOUND
SPA
SPACE
SPACE$
SPC
SPC(
SPEED=
SPUT
SQR
SQRT
ST
STATUS
STE
STEP
STICK
STO
STOP
STORE
STR
STR$
STRIG
STRING
STRING$
STUFF
SUB
SUBEND
SUM
SWAP
SYS
SYSTEM
TAB
TAB(
TAN
TAND
TANG
TANH
TAPPEND
TEXT
THE
THEN
TI
TI$
TIM
TIME
TIME$
TIMER
TLIST
TLOAD
TNH
TO
TOP
TRACE
TRACE OFF
TRACE ON
TRAP
TROFF
TRON
TSAVE
TYP
TYPE
UNLOAD
UNTIL
USER
USING
USR
VAL
VARPTR
VARPTR$
VERIFY
VIEW
VIEWPORT
VLIN
VLIN-AT
VPOS
VTAB
WAIT
WBYTE
WEAVE
WEND
WHILE
WIDTH
WINDOW
WRITE
WRITE#
XDRAW
XIO
XOR
XPLOT
XRA

dykstrom · 2022-12-01T08:58:40Z

Statements Used in Procedures (SUB, FUNCTION, DEF FN) are also currently shown in the same face as Control-Flow, but if there are any spare font-lock categories left, it may look better if they were subtly different.

It is also possible to create new font-lock categories. I don't know if that is considered good style though. One could do something like this:

(defface font-lock-operator-face
  '((((class grayscale) (background light)) :foreground "Gray90" :weight bold)
    (((class grayscale) (background dark))  :foreground "DimGray" :weight bold)
    (((class color) (min-colors 88) (background light)) :foreground "ForestGreen")
    (((class color) (min-colors 88) (background dark))  :foreground "PaleGreen")
    (((class color) (min-colors 16) (background light)) :foreground "ForestGreen")
    (((class color) (min-colors 16) (background dark))  :foreground "PaleGreen")
    (((class color) (min-colors 8)) :foreground "green")
    (t :weight bold :underline t))
  "Font Lock mode face used to highlight operators."
  :group 'font-lock-faces)

(defvar font-lock-operator-face 'font-lock-operator-face
  "Face name to use for operators.")

dykstrom · 2022-12-01T09:01:21Z

One feature it has that basic-mode.el should ~~steal~~ acquire is highlighting line numbers when they are referenced by statements like GOTO 10 in the line number color.

This is a good idea. But maybe it should be a separate issue, because it has nothing to do with highlighting categories?

hackerb9 · 2022-12-02T10:41:46Z

It is also possible to create new font-lock categories. I don't know if that is considered good style though.

I like that idea. I also don't know about the style guidelines, but I think it should be fine since it would only affect BASIC mode.

Creating new categories and aliasing the existing ones (functions/keywords/builtins) would allow categories that make sense for BASIC. I think the QBASIC manual is a good starting point, but I'd suggest merging some of the similar categories:

Control-Flow Statements (IF, THEN, FOR, NEXT)
- Statements Used in BASIC Procedures (GOSUB, CALL, DECLARE)
  Inherits from Control-Flow, but subtly different.
- Trapping Statements and Functions (ON ERR, RESUME, ERROR, ON event GOSUB)
  Inherits from Control-Flow, but more vivid to warn of surprising leaps.
I/O Statements (PRINT, INPUT, OPEN, SEEK)
- Graphics Statements and Functions (SCREEN, PSET, LINE)
  Inherits from I/O, but I see no need to differentiate by default
String-Processing Statements and Functions (MID$, VAL, ASC, CHR$)

Of course, the categories from that particular appendix are not exhaustive as they do not cover the more day-to-day categories:

Functions
- Returns a numeric value (ABS, FIX, MOD, FRE)
- Returns a string value (MID$, TIME$, STRING$)
Operators (+, -, <>, AND, XOR)
These are so common they should not be strongly highlighted, if at all
Types (CDBL, CONST)
General BASIC functions (PEEK, POKE, BEEP)

Click to see the full list of QBASIC reserved words.

ABS
ACCESS
ALIAS
AND
ANY
APPEND
AS
ASC
ATN
BASE
BEEP
BINARY
BLOAD
BSAVE
BYVAL
CALL
CALLS
CASE
CDBL
CDECL
CHAIN
CHDIR
CHR$
CINT
CIRCLE
CLEAR
CLNG
CLOSE
CLS
COLOR
COM
COMMANDS
COMMON
CONST
COS
CSNG
CSRLIN
CVD
CVDMBF
CVI
CVL
CVS
CVSMBF
DATA
DATES
DECLARE
DEF
DEFDBL
DEFINT
DEFLNG
DEFSNG
DEFSTR
DIM
DO
DOUBLE
DRAW
ELSE
ELSEIF
END
ENDIF
ENVIRON
ENVIRONS
EOF
EQV
ERASE
ERDEV
ERDEVS
ERL
ERR
ERROR
EXIT
EXP
FIELD
FILEATTR
FILES
FIX
FOR
FRE
FREEFILE
FUNCTION
GET
GOSUB
GOTO
HEX$
IF
IMP
INKEYS
INP
INPUT
INPUTS
INSTR
INT
INTEGER
IOCTL
IOCTLS
IS
KEY
KILL
LBOUND
LCASES
LEFTS
LEN
LET
LINE
LIST
LOC
LOCAL
LOCATE
LOCK
LOF
LOG
LONG
LOOP
LPOS
LPRINT
LSET
LTRIMS
MID$
MKD$
MKDIR
MKDMBFS
MKI$
MKL$
MKSMBFS
MKSS
MOD
NAME
NEXT
NOT
OCT$
OFF
ON
OPEN
OPTION
OR
OUT
OUTPUT
PAINT
PALETTE
PCOPY
PEEK
PEN
PLAY
PMAP
POINT
POKE
POS
PRESET
PRINT
PSET
PUT
RANDOM
RANDOMIZE
READ
REDIM
REM
RESET
RESTORE
RESUME
RETURN
RIGHTS
RMDIR
RND
RSET
RTRIMS
RUN
SADD
SCREEN
SEEK
SEG
SELECT
SETMEM
SGN
SHARED
SHELL
SIGNAL
SIN
SINGLE
SLEEP
SOUND
SPACES
SPC
SQR
STATIC
STEP
STICK
STOP
STR$
STRIG
STRING
STRINGS
SUB
SWAP
SYSTEM
TAB
TAN
THEN
TIMER
TIMES
TO
TROFF
TRON
TYPE
UBOUND
UCASES
UEVENT
UNLOCK
UNTIL
USING
VAL
VARPTR
VARPTRS
VARSEG
VIEW
WAIT
WEND
WHILE
WIDTH
WINDOW
WRITE
XOR

hackerb9 mentioned this issue Oct 26, 2022

Support dialects of BASIC #20

Closed

hackerb9 mentioned this issue Dec 2, 2022

Highlight references to line numbers using the line number color #26

Closed

dykstrom added the enhancement label Dec 2, 2022

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Syntax highlighting categories #21

Syntax highlighting categories #21

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Syntax highlighting categories #21

Syntax highlighting categories #21

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