HIGHLIGHT$(string-expression)
Given a string containing BASIC source, returns a copy with ANSI SGR escape sequences applied for syntax highlighting. Intended for program listings, editors, and tools that render to an ANSI-capable terminal, producing a consistent look-and-feel.
Notes
- Strings — text between double quotes ("...") is highlighted in light yellow from the opening quote to the closing quote. If a closing quote is missing, highlighting continues to the end of the input and is then reset.
- Comments
- A single quote (') begins a comment that is highlighted in dark green until the end of the input.
- The keyword REM (when not inside a string) causes the entire line to be treated as a comment and highlighted in dark green.
- Keywords / tokens — recognised BASIC keywords are highlighted in light blue when they are not part of a longer identifier. Boundary detection prevents colouring inside names like FORTH. Exceptions: PROC, FN, and = may be adjacent to letters/digits/underscores and will still be highlighted.
- Built-in functions
- Integer-returning built-ins are light green.
- String-returning built-ins are light magenta.
- Real/float-returning built-ins are light cyan.
- Numeric literals — digits (and a leading unary +/-) are highlighted in orange.
- Operators & punctuation — () + - * / = < > , ; are highlighted in dark red.
- Default text — rendered in white. Colours are reset back to white after each coloured span, and a final reset is appended at the end of the result to prevent “colour leakage” in the caller’s terminal.
Errors
Examples
' Strings and a trailing comment
A$ = "PRINT " + CHR$(34) + "hello world" + CHR$(34) + " ' This is an example"
PRINT HIGHLIGHT$(A$)
' Keywords, numbers, and operators
B$ = "FOR I = 1 TO 10 + 8"
PRINT HIGHLIGHT$(B$)
' REM comment colours the whole line as a comment
D$ = "REM this whole line is a comment"
PRINT HIGHLIGHT$(D$)
See also
1.14.0