|
From: | John Snow |
Subject: | Re: [Qemu-devel] [PATCH v4 2/4] scripts: qmp-shell: Expand support for QMP expressions |
Date: | Wed, 29 Apr 2015 16:09:15 -0400 |
User-agent: | Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 |
On 04/29/2015 03:25 PM, Eric Blake wrote:
On 04/29/2015 01:14 PM, John Snow wrote:This includes support for [] expressions, single-quotes in QMP expressions (which is not strictly a part of JSON), and the ability to use "True", "False" and "None" literals instead of JSON's equivalent true, false, and null literals. qmp-shell currently allows you to describe values as JSON expressions: key={"key":{"key2":"val"}} But it does not currently support arrays, which are needed for serializing and deserializing transactions: key=[{"type":"drive-backup","data":{...}}] qmp-shell also only currently accepts doubly quoted strings as-per JSON spec, but QMP allows single quotes. Lastly, python allows you to utilize "True" or "False" as boolean literals, but JSON expects "true" or "false". Expand qmp-shell to allow the user to type either, converting to the correct type. As a consequence of the above, the key=val parsing is also improved to give better error messages if a key=val token is not provided. CAVEAT: The parser is still extremely rudimentary and does not expect to find spaces in {} nor [] expressions. This patch does not improve this functionality. Signed-off-by: John Snow <address@hidden> --- scripts/qmp/qmp-shell | 63 ++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 47 insertions(+), 16 deletions(-)+class FuzzyJSON(ast.NodeTransformer): + '''This extension of ast.NodeTransformer filters literal "true/false/null" + values in an AST and replaces them by proper "True/False/None" values that + Python can properly evaluate.''' + def visit_Name(self, node): + if node.id == 'true': + node.id = 'True' + if node.id == 'false': + node.id = 'False' + if node.id == 'null': + node.id = 'None' + return nodeCute!
;)
Reviewed-by: Eric Blake <address@hidden>
So the only remaining crime I am aware of is that when specifying key=val pairs without hoping for a favorable QMP deserialization is that we still accept e.g. "TrUe" and "FaLSe" and so on.
Patch 4 tries to make amends by explicitly converting objects back to strict JSON and printing that out for the user (if they supplied -v) so we can observe what conversions qmp-shell made for us to make things nice.
And I think I'm done playing with this for now. If I go any further, there's bound to be flex and bison files in the tree!
--js
[Prev in Thread] | Current Thread | [Next in Thread] |