Initial Commit

Working base grammar, visitor, client, context.
Good test coverage for grammar constructs.

customcmd/client.py

@@ -0,0 +1,54 @@
+import regex
+
+from parsimonious.grammar import Grammar
+
+from .context import ExecContext
+from .parser import Execuitor
+from .terms import ExecutorTerm
+
+fragment_re = regex.compile(r"\$(?<br>{(?:[^{}]++|(?&br))*})")
+
+
+class ExecClient:
+    def __init__(self):
+        self.grammer: Grammar = self.load_grammar()
+        self.execuitor: Execuitor = Execuitor()
+
+        self.globals = {}
+
+    def load_grammar(self):
+        with open("assets/grammar.ppeg") as f:
+            return Grammar(f.read())
+
+    def _parse_fragment(self, cmd: str) -> ExecutorTerm:
+        """
+        Parse a provided fragment into an ExecutorTerm.
+
+        This could reasonably be LRU cached.
+        """
+        tree = self.grammer.parse(cmd)
+        term = self.execuitor.visit(tree)
+        return term
+
+    async def run_command(self, ctx: ExecContext, command: str) -> str:
+        """
+        Process the given command string,
+        executing and replacing each fragment.
+
+        Executes in the given context,
+        which will generally be constructed through subclass methods.
+        """
+        result = []
+        last_end = 0
+
+        for match in regex.finditer(fragment_re, command):
+            result.append(command[last_end : match.start()])
+
+            fragment = command[match.start() : match.end()]
+            parsed = self._parse_fragment(fragment)
+            fragment_result = await parsed.execute(ctx)
+
+            result.append(fragment_result)
+            last_end = match.end()
+
+        return "".join(result)