HP42S-free42

May 22, 2025 · View on GitHub

License

Language support for RPN programming language on the HP42S/free42 calculators.

What's new in HP42S-free42:

refactoring code based parsers, with generated PEG parsers using grammars from peggy.js
improved log with more details for error analysis
more commands until free42 v3.3.5
package updates
comments only using //

Usage

Format -> Encode -> Decode -> Encode -> ...

Demo

Syntax-check

completion-label

Features

syntax highlighting
syntax checking
string length checking
label suggestions
snipptes with description
comments
document formatter
encoding code to raw
decoding raw to code
generated parsers from grammars

Supported filetypes:

*.hp42s for the original operation set of the HP-42S
*.free42 for the extended operation set of the free42
*.hex42 with detailed encoding/decoding information
*.log with detailed encoding/decoding progress when error occurs

Limitations

Line numbers: They are required for the HP42S/free42 code. They are generated by the formatter.
Single/Double Quotes: The formatter will change outer double quotes to single quotes, when the string contains although double quotes ("ABC"ABC" -> 'ABC"ABC').
Comments: Comments only starts with //. Former comments with @ or # are not supported anymore.

`Encode Code from Editor`

Before encoding, please format the code. This avoids further special cases that would otherwise have to be taken into account.

Press Win/Linux: Ctrl+Shift+P, Mac-OSX: ⇧⌘P, then write HP42S to get the command hp42s/free42: Encode Code from Editor in the drop down list.
The hp42s/free42: Encode Code from Editor command generates a *.hp42s.raw or *.free42.raw file. These files can be loaded by free42 or DM42.
Depending on the setting HP42S/free42.encoderGenerateHexFile setting, the command will generate a readable hex42 file.
Although the program size will be calculated and shown in the first line ({ n-Byte Prgm }). For some reason, the last ending END command is ignored. Real program size will be 3 bytes more.

That's what the real HP-42S does. It is strange, since the END is, in fact, a part of the program... but that's the way it is.

`Decode Code from Editor`

From a *.raw file the decoder generates the following files

*.hex42: The sequence of the command bytes, when setting HP42S/free42.decoderGenerateHexFile is checked.
*.hp42s: The code file with only pure HP42S commands.
*.free42: The decode has detected free42 commands. The code will only run on free42 applications.

The endless chain of encoding and decoding

Each operation creates new files with additional file extensions appended.

  Format           ->    Encode                        ->    Decode                                  ->    Encode  ...

         '*.hp42s' -> '*.hp42s.hex42' -> '*.hp42s.raw' -> '*.hp42s.raw.hex42' -> '*.hp42s.raw.hp42s' ->            ...

Features

Instruction sets

HP42S instruction set
Free42 Extensions to the HP-42S Instruction Set

Syntax Highligthing

Syntax highlighting for the HP42S and free42 commands

Snippets with description

Every keystroke command and its variations with a description.
Normal snippets appear when writing the command
Snippets for commands with leading special character appear when writing the command name (eg: use DEC for →DEC, use REG for ΣREG)
Use e, ᴇ or E for ᴇ in 1.2ᴇ-23
Use OP for ×,÷,+/-,Σ+,Σ-,←,↑,↓,→,%,⊢,%CH
Use FLAG for all flags 01 to 99
Use FOC for √,∫,░,Σ,▶,π,¿,␊,≤,≥,≠,↵,↓,→,←,µ,£,°,Å,Ñ,Ä,∡,ᴇ,Æ,…,␛,Ö,Ü,▒,■
Use [LF] or ␊ for a line feed in a string. Formatter will replace [LF] to ␊.

Comments

Comments complete line with //
Comments at end of line with //

Document Formatter

The formatter prepares the code for encoding.
It will replace all abbreviations, which are used for ascii text editing.
When using Visual Studio Code, the code is displayed in UTF8, though all original characters of the HP42S/free42 can be displayed correct.

However when I enter a program manually into a real calculator it helps to have line numbers. If I miss a command it helps to find the error.
Right-click in the editor to get the context menu, then select menu Format Document or press keyboard-shortcut Win: SHIFT+ALT+F/ Linux: SHIFT+ALT+F/ Mac-OSX: ⇧⌥F.

The formatter has several settings:

Remove Too Long Spaces: This will reduce whitespaces in the code.
Replace Abbreviations: Abbreviations for special characters will be replaced by the correct intended character.
Trim Line: This removes whitespaces at the beginnning and at the end of a code line.

The hex42 files has these additional settings: