Merge branch 'dev' into example/simple_scripts

.gitignore

@@ -2,7 +2,7 @@ venv
 .vscode
 __tmp_eopsin.py
 test.py
-test/
+build/
 *.uplc
 *.cbor
 *.plutus

.travis.yml

@@ -19,11 +19,11 @@ script:
 - coverage run --source=eopsin setup.py test
 # the samples from the README file
 - >
-  coverage run -a --source=eopsin -m eopsin eval examples/smart_contracts/assert_sum.py "{\"int\": 4}" "{\"int\": 38}" "{\"constructor\": 0, \"fields\": []}"
+  coverage run -a --source=eopsin -m eopsin eval examples/smart_contracts/assert_sum.py "{\"int\": 4}" "{\"int\": 38}" "{\"constructor\": 6, \"fields\": []}"
 - >
   coverage run -a --source=eopsin -m eopsin compile examples/smart_contracts/assert_sum.py > assert_sum.uplc
 - >
-  coverage run -a --source=eopsin -m eopsin eval_uplc examples/smart_contracts/assert_sum.py "{\"int\": 4}" "{\"int\": 38}" "{\"constructor\": 0, \"fields\": []}"
+  coverage run -a --source=eopsin -m eopsin eval_uplc examples/smart_contracts/assert_sum.py "{\"int\": 4}" "{\"int\": 38}" "{\"constructor\": 6, \"fields\": []}"
 - >
   coverage run -a --source=eopsin -m eopsin compile_pluto examples/smart_contracts/assert_sum.py
 - >

README.md

@@ -30,6 +30,16 @@ If the program compiles then:
 
 ### Getting Started
 
+#### Example repository
+
+Check out this example repository for a quick start in setting up a development environment
+and compiling some sample contracts yours:
+
+https://github.com/ImperatorLang/eopsin-example
+
+You can replace the contracts in your local copy of the repository with code from the
+`examples` section here to start exploring different contracts.
+
 #### Developer Community and Questions
 
 This repository contains a discussions page.
@@ -38,6 +48,9 @@ Others may be able to help you and will also benefit from the previously shared
 
 Check out the community [here](https://github.com/ImperatorLang/eopsin/discussions)
 
+Alternatively, feel free to join the welcoming discord community
+at the TxPipe server: https://discord.gg/2ETSZnQQH9
+
 #### Installation
 
 Install Python 3.8. Then run
@@ -50,16 +63,32 @@ python3.8 -m pip install eopsin-lang
 
 A short non-complete introduction in starting to write smart contracts follows.
 
-1. Make sure you understand python. Eopsin works like python and uses python. There are tons of tutorials for python, choose what suits you best.
-2. Make sure your contract is valid python and the types check out. Write simple contracts first and run them using `eopsin eval` to get a feeling for how they work.
-3. Make sure your contract is valid eopsin code. Run `eopsin compile` and look at the compiler erros for guidance along what works and doesn't work and why.
-4. Dig into the [`examples`](https://github.com/ImperatorLang/eopsin/tree/master/examples) to understand common patterns. Check out the [`prelude`](https://imperatorlang.github.io/eopsin/eopsin/prelude.html) for understanding how the Script Context is structured and how complex datums are defined.
+1. Make sure you understand EUTxOs, Addresses, Validators etc on Cardano. [There is a wonderful crashcourse by @KtorZ](https://aiken-lang.org/fundamentals/eutxo). The contract will work on these concepts
+2. Make sure you understand python. Eopsin works like python and uses python. There are tons of tutorials for python, choose what suits you best.
+3. Make sure your contract is valid python and the types check out. Write simple contracts first and run them using `eopsin eval` to get a feeling for how they work.
+4. Make sure your contract is valid eopsin code. Run `eopsin compile` and look at the compiler erros for guidance along what works and doesn't work and why.
+5. Dig into the [`examples`](https://github.com/ImperatorLang/eopsin/tree/master/examples) to understand common patterns. Check out the [`prelude`](https://imperatorlang.github.io/eopsin/eopsin/prelude.html) for understanding how the Script Context is structured and how complex datums are defined.
+6. Check out the [sample repository](https://github.com/ImperatorLang/eopsin-example) to find a sample setup for developing your own contract.
+
+
+In summary, a smart contract in eopsin is defined by the function `validator` in your contract file.
+The function validates that a specific value can be spent, minted, burned, withdrawn etc, depending
+on where it is invoked/used as a credential.
+If the function fails (i.e. raises an error of any kind such as a `KeyError` or `AssertionError`)
+the validation is denied, and the funds can not be spent, minted, burned etc.
+
+> There is a subtle difference here in comparison to most other Smart Contract languages.
+> In eopsin a validator may return anything (in particular also `False`) - as long as it does not fail, the execution is considered valid.
+> This is more similar to how contracts in Solidity always pass, unless they run out of gas or hit an error.
+> So make sure to `assert` what you want to ensure to hold for validation!
 
 A simple contract called the "Gift Contract" verifies that only specific wallets can withdraw money.
 They are authenticated by a signature.
-See the [tutorial by `pycardano`](https://pycardano.readthedocs.io/en/latest/guides/plutus.html) for explanations on what each of the parameters to the validator means
+If you don't understand what a pubkeyhash is and how this validates anything, check out [this gentle introduction into Cardanos EUTxO](https://aiken-lang.org/fundamentals/eutxo).
+Also see the [tutorial by `pycardano`](https://pycardano.readthedocs.io/en/latest/guides/plutus.html) for explanations on what each of the parameters to the validator means
 and how to build transactions with the contract.
 
+
 ```python3
 from eopsin.prelude import *
 
@@ -153,5 +182,6 @@ Donation in ADA can be submitted to `$imperatorlang` or `addr1qyz3vgd5xxevjy2rvq
 
 ### Supporters
 
+<a href="https://github.com/inversion-dev"><img src="https://avatars.githubusercontent.com/u/127298233?s=200&v=4" width="50></a>
 <a href="https://github.com/MuesliSwapTeam/"><img  src="https://avatars.githubusercontent.com/u/91151317?v=4" width="50" /></a>
 <a href="https://github.com/AadaFinance/"><img  src="https://avatars.githubusercontent.com/u/89693711?v=4" width="50" /></a>

eopsin/__init__.py

@@ -8,7 +8,7 @@
 except ImportError as e:
     warnings.warn(ImportWarning(e))
 
-VERSION = (0, 9, 3)
+VERSION = (0, 9, 9)
 
 __version__ = ".".join([str(i) for i in VERSION])
 __author__ = "nielstron"

eopsin/__main__.py

@@ -93,9 +93,13 @@ def main():
         source_code = f.read()
 
     if command == Command.eval:
-        with open("__tmp_eopsin.py", "w") as fp:
-            fp.write(source_code)
-        sc = importlib.import_module("__tmp_eopsin")
+        if args.input_file == "-":
+            with open("__tmp_eopsin.py", "w") as fp:
+                fp.write(source_code)
+            input_file = "__tmp_eopsin.py"
+        sys.path.append(str(pathlib.Path(input_file).parent.absolute()))
+        sc = importlib.import_module(pathlib.Path(input_file).stem)
+        sys.path.pop()
         print("Starting execution")
         print("------------------")
         try:
@@ -110,14 +114,16 @@ def main():
         print("------------------")
         print(ret)
 
-    source_ast = compiler.parse(source_code)
+    source_ast = compiler.parse(source_code, filename=input_file)
 
     if command == Command.parse:
         print("Parsed successfully.")
         return
 
     try:
-        code = compiler.compile(source_ast, force_three_params=args.force_three_params)
+        code = compiler.compile(
+            source_ast, filename=input_file, force_three_params=args.force_three_params
+        )
     except CompilerError as c:
         # Generate nice error message from compiler error
         if not isinstance(c.node, ast.Module):
@@ -168,10 +174,10 @@ def main():
                     "Please supply an output directory if no input file is specified."
                 )
                 exit(-1)
-            target_dir = pathlib.Path(pathlib.Path(input_file).stem)
+            target_dir = pathlib.Path("build") / pathlib.Path(input_file).stem
         else:
             target_dir = pathlib.Path(args.output_directory)
-        target_dir.mkdir(exist_ok=True)
+        target_dir.mkdir(exist_ok=True, parents=True)
         uplc_dump = code.dumps()
         cbor_hex = pyaiken.uplc.flat(uplc_dump)
         # create cbor file for use with pycardano/lucid
@@ -212,7 +218,7 @@ def main():
         print("------------------")
         assert isinstance(code, uplc.ast.Program)
         try:
-            ret = uplc.dumps(uplc.eval(f))
+            ret = uplc.dumps(uplc.eval(code))
         except Exception as e:
             print("An exception was raised")
             ret = e

eopsin/compiler.py

@@ -839,10 +839,10 @@ def generic_visit(self, node: AST) -> plt.AST:
         raise NotImplementedError(f"Can not compile {node}")
 
 
-def compile(prog: AST, force_three_params=False):
+def compile(prog: AST, filename=None, force_three_params=False):
     rewrite_steps = [
         # Important to call this one first - it imports all further files
-        RewriteImport(),
+        RewriteImport(filename=filename),
         # Rewrites that simplify the python code
         RewriteAugAssign(),
         RewriteTupleAssign(),

eopsin/rewrite/rewrite_import.py

@@ -1,6 +1,8 @@
 import importlib
+import importlib.util
 import pathlib
 import typing
+import sys
 from ast import *
 
 from ..util import CompilingNodeTransformer
@@ -10,9 +12,41 @@
 """
 
 
+def import_module(name, package=None):
+    """An approximate implementation of import."""
+    absolute_name = importlib.util.resolve_name(name, package)
+    try:
+        return sys.modules[absolute_name]
+    except KeyError:
+        pass
+
+    path = None
+    if "." in absolute_name:
+        parent_name, _, child_name = absolute_name.rpartition(".")
+        parent_module = import_module(parent_name)
+        path = parent_module.__spec__.submodule_search_locations
+    for finder in sys.meta_path:
+        spec = finder.find_spec(absolute_name, path)
+        if spec is not None:
+            break
+    else:
+        msg = f"No module named {absolute_name!r}"
+        raise ModuleNotFoundError(msg, name=absolute_name)
+    module = importlib.util.module_from_spec(spec)
+    sys.modules[absolute_name] = module
+    spec.loader.exec_module(module)
+    if path is not None:
+        setattr(parent_module, child_name, module)
+    return module
+
+
 class RewriteImport(CompilingNodeTransformer):
     step = "Resolving imports"
 
+    def __init__(self, filename=None, package=None):
+        self.filename = filename
+        self.package = package
+
     def visit_ImportFrom(
         self, node: ImportFrom
     ) -> typing.Union[ImportFrom, typing.List[AST]]:
@@ -28,14 +62,19 @@ def visit_ImportFrom(
             node.names[0].asname == None
         ), "The import must have the form 'from <pkg> import *'"
         # TODO set anchor point according to own package
-        module_file = pathlib.Path(importlib.import_module(node.module).__file__)
+        if self.filename:
+            sys.path.append(str(pathlib.Path(self.filename).parent.absolute()))
+        module = import_module(node.module, self.package)
+        if self.filename:
+            sys.path.pop()
+        module_file = pathlib.Path(module.__file__)
         assert (
             module_file.suffix == ".py"
         ), "The import must import a single python file."
         # visit the imported file again - make sure that recursive imports are resolved accordingly
         with module_file.open("r") as fp:
             module_content = fp.read()
-        recursively_resolved: Module = self.visit(
-            parse(module_content, filename=module_file.name)
-        )
+        recursively_resolved: Module = RewriteImport(
+            filename=str(module_file), package=module.__package__
+        ).visit(parse(module_content, filename=module_file.name))
         return recursively_resolved.body

eopsin/type_inference.py

@@ -242,7 +242,7 @@ def visit_If(self, node: If) -> TypedIf:
             ), "Can only cast instances, not classes"
             assert isinstance(
                 target_inst_class.typ, UnionType
-            ), "Can only cast instances of Union types"
+            ), "Can only cast instances of Union types of PlutusData"
             assert isinstance(target_class, RecordType), "Can only cast to PlutusData"
             assert (
                 target_class in target_inst_class.typ.typs

eopsin/typed_ast.py

@@ -1023,7 +1023,15 @@ def empty_list(p: Type):
         el = empty_list(p.typ.typ)
         return plt.EmptyListList(uplc.BuiltinList([], el.sample_value))
     if isinstance(p.typ, DictType):
-        plt.EmptyDataPairList()
+        return plt.EmptyListList(
+            uplc.BuiltinList(
+                [],
+                uplc.BuiltinPair(
+                    uplc.PlutusConstr(0, FrozenList([])),
+                    uplc.PlutusConstr(0, FrozenList([])),
+                ),
+            )
+        )
     if isinstance(p.typ, RecordType) or isinstance(p.typ, AnyType):
         return plt.EmptyDataList()
     raise NotImplementedError(f"Empty lists of type {p} can't be constructed yet")

eopsin/util.py

@@ -552,5 +552,7 @@ def data_from_json(j: typing.Dict[str, typing.Any]) -> uplc.PlutusData:
     if "map" in j:
         return uplc.PlutusMap({d["k"]: d["v"] for d in j["map"]})
     if "constructor" in j and "fields" in j:
-        return uplc.PlutusConstr(j["constructor"], j["fields"])
+        return uplc.PlutusConstr(
+            j["constructor"], list(map(data_from_json, j["fields"]))
+        )
     raise NotImplementedError(f"Unknown datum representation {j}")