Requirements

Install phoityne-vscode from hackage.

Especially for GHC8

Install phoityne-vscode and haskell-dap.
In the launch.json, add "--with-ghc=haskell-dap" to ghciCmd variable.

> stack install phoityne-vscode haskell-dap

Limitations

• The source file extension must be ".hs"
• Can not use STDIN handle while debugging.
• Using GHC7, see the README.

Features

Continue & Steps

Stacktrace

The variable added to watch will be forced.

Bindings

Break condition

Console output

Quick Start

This is a new experimental feature.
Note!!, This function will automatically change the .vscode / launch.json file.

Shortcut keys

When you start debugging for the first time, .vscode/tasks.json will be created automatically. Then you can use F6, F7, F8 shortcut keys.

• F5 : start debug
• F6 : show command menu (for stack watch)
• Shift + F6 : stop stack watch
• F7 : stack clean & build
• F8 : stack test
• F9 : put a breakpoint on the current line
• Shift + F9 : put a breakpoint on the current column

While debugging, you can use F5, F9, F10, F11 shortcut keys.

• F5 : jump to next bp
• F9 : put bp on the line
• Shift + F9 : put bp on the column
• F10 : step next
• F11 : step into

Configuration

.vscode/launch.json

changing ghci initial prompt

If you change ghci prompt in .ghci file, or ghci prompt is changed from "Prelude>" by applying NoImplicitPrelude extension, set the initial prompt variable to same prompt string.

% diff .vscode/launch.json.old .vscode/launch.json
19c19
<             "ghciInitialPrompt": "Prelude> "      // default value.
---
>             "ghciInitialPrompt": "> "             // e.g.
%

Make sure needs of the last space, and don't forget adding it.

setting the startup hs file

Set the startup variable to the path of .hs file in which main function is defined.

% diff .vscode/launch.json.old .vscode/launch.json
10c10
<             "startup": "${workspaceRoot}/test/Spec.hs",    // default value.
---
>             "startup": "${workspaceRoot}/app/run.hs",     // e.g.
%

setting the startup function

If you want to run the specific function instead of main function, set the startupFunc variable.
For example, when specifying the following startDebug function,

startDebug :: String -> IO ()
startDebug name = do
  putStrLn "hello"
  putStrLn name 

set the valiavles in the launch.json file.

% diff .vscode/launch.json.old .vscode/launch.json
11c12
<             "startupFunc": "",    // default value.
<             "startupArgs": "",    // default value.
---
>             "startupFunc": "startDebug",       // e.g.
>             "startupArgs": "\"phoityne\"",     // e.g.
%

changing log level

For debugging phoityne itself, change the log level to DEBUG.
Adding Issue with the debug log.

% diff .vscode/launch.json.old .vscode/launch.json
12c12
<             "logLevel": "WARNING",               // default value.
---
>             "logLevel": "DEBUG",                 // e.g.
%

.vscode/tasks.json

Thanks

Thank you for your contribution for this project.

• @hnefatl