add unimplemented nodes to AST instead of raising exceptions #86
Description
To facilitate broader coverage of the analyzer, it would be good for the parser to add "unimplemented nodes" to the AST rather than raising an error. This can be done as follows:
$ git-diff bashlex/parser.py
...
+from mezcla import system
+
+ADD_UNIMPLEMENTED_NODE = system.getenv_bool("ADD_UNIMPLEMENTED_NODE", False,
+ "Add unimplemented nodes to parse tree")
+
from bashlex import yacc, tokenizer, state, ast, subst, flags, errors, heredoc
def _partsspan(parts):
@@ -13,14 +19,21 @@ precedence = (
)
def handleNotImplemented(p, type):
- if len(p) == 2:
+ if ADD_UNIMPLEMENTED_NODE:
+ parts = _makeparts(p)
+ p[0] = ast.node(kind='unimplemented', parts=parts, pos=_partsspan(parts))
+ elif len(p) == 2:
raise NotImplementedError('type = {%s}, token = {%s}' % (type, p[1]))
else:
raise NotImplementedError('type = {%s}, token = {%s}, parts = {%s}' % (type, p[1], p[2]))
This way, a parse tree can still be recovered even though a particular construct is not supported:
$ ADD_UNIMPLEMENTED_NODE=1 python -c 'import bashlex; print(bashlex.parse("case fu in esac")[0].dump())'
UnimplementedNode(pos=(0, 15), parts=[
ReservedwordNode(pos=(0, 4), word='case'),
WordNode(pos=(5, 7), word='fu'),
ReservedwordNode(pos=(8, 10), word='in'),
ReservedwordNode(pos=(11, 15), word='esac'),
])
I can add a pull request for this if you want.