PsBash.Transpiler 0.10.5

PsBash.Transpiler

The bash → PowerShell transpiler that powers PsBash: a hand-written lexer + recursive-descent parser (AST modeled on Oils/OSH) and a PowerShell emitter. It is a leaf library with no PsBash dependencies (only Parlot), so you can embed bash-to-PowerShell translation in your own app — for example to build your own shell on top of a PowerShell runspace.

dotnet add package PsBash.Transpiler

Transpile bash to PowerShell

using PsBash.Core.Transpiler; // assembly: PsBash.Transpiler

string ps = BashTranspiler.Transpile("ls -la | grep .log | sort -k5 -rn | head -5");
// ps == "Invoke-BashLs -la | Invoke-BashGrep .log | Invoke-BashSort -k5 -rn | Invoke-BashHead -5"

Transpile accepts an optional TranspileContext (Default, or Eval for eval-style in-process re-transpilation). Use TranspileWithMap when you need to map a PowerShell runtime error back to the originating bash line:

TranspileResult result = BashTranspiler.TranspileWithMap("for x in a b c; do echo $x; done");
string ps = result.PowerShell;       // emitted PowerShell
// result.LineMap: emitted line -> source bash line

Build your own shell

The emitted PowerShell calls Invoke-Bash* commands (e.g. Invoke-BashGrep). To run it with full fidelity, load the ps-bash runtime module into your runspace, then execute the transpiled text:

using System.Management.Automation;
using System.Management.Automation.Runspaces;

using var rs = RunspaceFactory.CreateRunspace();
rs.Open();
using var ps = PowerShell.Create();
ps.Runspace = rs;

// Load the runtime: the PsBash module (Invoke-Bash* commands) ships embedded in
// the PsBash.Core package and is extracted at runtime — add a reference to
// `PsBash.Core` and import the extracted module, or `Install-Module PsBash` /
// `PsBash.Cmdlets` from the PowerShell Gallery into the runspace.
ps.AddScript("Import-Module PsBash").Invoke();
ps.Commands.Clear();

string transpiled = BashTranspiler.Transpile(userBashLine);
foreach (var item in ps.AddScript(transpiled).Invoke())
    Console.WriteLine(item);

A REPL is then just: read a line → BashTranspiler.Transpile → run in the runspace → print. Add history, completion, and prompt handling to taste. See the ps-bash PsBash.Shell project for a complete launcher + host implementation.

Scope

• In scope: bash syntax → PowerShell text. Lexer, parser, AST (PsBash.Core.Parser.Ast), emitter.
• Out of scope (use PsBash.Core): the runtime Invoke-Bash* command implementations, the IPC host, and process orchestration.

License

MIT — see the repository.