txsc

txsc (tx script compiler) is a Bitcoin transaction script compiler.

Usage

Run setup.py install. The script txsc (which refers to txsc.compiler.py) will be installed. You can also run compiler.py locally, but you won't be able to use any languages added by plugins.

Unless specified, txsc will assume that the source language is txscript and the target language is BTC (see below for explanations of what these languages are).

You can either invoke txsc with a string or with a filename. If a filename is specified, the file extension will be used to determine the source language if one is present.

Compile raw BTC to ASM:

txsc "5255935788" -s btc -t asm
2 5 ADD 7 EQUALVERIFY

Compile txscript to BTC and ASM:

$ txsc "2 + 5 == 7;"
5255935787
$ txsc "2 + 5 == 7;" -t asm
2 5 ADD 7 EQUAL

With -v, optimizations will be shown:

$ txsc "verify 2 + 5 == 7;" -t asm -v
Linear Intermediate Representation:
  ['OP_2', 'OP_5', 'OP_ADD', 'OP_7', 'OP_EQUAL', 'OP_VERIFY']

Optimized Linear Representation:
  ['OP_2', 'OP_5', 'OP_ADD', 'OP_7', 'OP_EQUALVERIFY']

asm:
  2 5 ADD 7 EQUALVERIFY

Configuration Files

If a file called txsc.conf exists in the directory that txsc is being run in, it will be loaded by the compiler. A configuration file may also exist at $HOME/.config/txsc/txsc.conf. If the command-line option --config is supplied, it will be used instead of these paths. The configuration file is in JSON format. Options in the configuration file are overriden by command-line options.

Here is a sample of what a configuration file may look like:

{
    "log_level": "error",
    "target_lang": "asm"
}

The above configuration file specifies that only errors should be logged, and that asm is the target language to compile source to.

Languages

ASM

ASM represents a script as assembly instructions. Data pushes are hex-encoded, and prefixed with their size.

BTC

BTC refers to the raw, hex-encoded script format that Bitcoin scripts are sometimes represented as.

TxScript

txsc includes a language used to construct transaction scripts. It's based on Python. It works by parsing code and generating a structural intermediate representation, then transforming that into the linear intermediate representation that other languages can use.

See the TxScript documentation for detailed information regarding TxScript.

Examples

See the examples folder for scripts that txsc can be called with directly.

Credits

txsc is based loosely on Superscript compiler, an educational Bitcoin script compiler.