uast_extract does not allow to extract nested properties

[erizocosmico]

There is currently no way to allow extraction of nested properties of a node, which would be useful for getting, for example, the line and column of the position.

[kuba--]

it should be done with
#701

[kuba--]

It's doable, but we have to discuss in what format we want to return extracted data.
Here is a one big object in json:

[
{
 "@pos":{
 "@type": "uast:Positions",
 "end":{
 "@type": "uast:Position",
 "col": 8,
 "line": 4,
 "offset": 31
 },
 "start":{
 "@type": "uast:Position",
 "col": 5,
 "line": 4,
 "offset": 28
 }
 },
 "@role": [
 "Function",
 "Declaration",
 "Name",
 "Identifier"
 ],
 "@token": "sum",
 "@type": "FunctionDef",
 "args":{
 "@pos":{
 "@type": "uast:Positions"
 },
 "@role": [
 "Function",
 "Declaration",
 "Argument",
 "Incomplete"
 ],
 "@type": "arguments",
 "args": [
{
 "@pos":{
 "@type": "uast:Positions",
 "end":{
 "@type": "uast:Position",
 "col": 10,
 "line": 4,
 "offset": 33
 },
 "start":{
 "@type": "uast:Position",
 "col": 9,
 "line": 4,
 "offset": 32
 }
 },
 "@role": [
 "Function",
 "Declaration",
 "Argument",
 "Name"
 ],
 "@token": "a",
 "@type": "arg",
 "annotation": null,
 "noops_previous":{
 "@pos":{
 "@type": "uast:Positions",
 "end":{
 "@type": "uast:Position",
 "col": 1,
 "line": 3,
 "offset": 23
 },
 "start":{
 "@type": "uast:Position",
 "col": 1,
 "line": 1,
 "offset": 0
 }
 },
 "@role": [
 "Noop"
 ],
 "@type": "PreviousNoops",
 "lines": [
{
 "@pos":{
 "@type": "uast:Positions",
 "start":{
 "@type": "uast:Position",
 "col": 1,
 "line": 2,
 "offset": 1
 }
 },
 "@role": [
 "Comment",
 "Noop"
 ],
 "@token": "#!/usr/bin/env python\\n",
 "@type": "NoopLine"
 }
 ]
 }
 },
{
 "@pos":{
 "@type": "uast:Positions",
 "end":{
 "@type": "uast:Position",
 "col": 13,
 "line": 4,
 "offset": 36
 },
 "start":{
 "@type": "uast:Position",
 "col": 12,
 "line": 4,
 "offset": 35
 }
 },
 "@role": [
 "Function",
 "Declaration",
 "Argument",
 "Name"
 ],
 "@token": "b",
 "@type": "arg",
 "annotation": null
 }
 ]
 },
 "body":{
 "@role": [
 "Function",
 "Declaration",
 "Body"
 ],
 "@type": "FunctionDef.body",
 "body_stmts": [
{
 "@pos":{
 "@type": "uast:Positions",
 "end":{
 "@type": "uast:Position",
 "col": 8,
 "line": 5,
 "offset": 46
 },
 "start":{
 "@type": "uast:Position",
 "col": 2,
 "line": 5,
 "offset": 40
 }
 },
 "@role": [
 "Return",
 "Statement"
 ],
 "@token": "return",
 "@type": "Return",
 "value":{
 "@pos":{
 "@type": "uast:Positions",
 "start":{
 "@type": "uast:Position",
 "col": 9,
 "line": 5,
 "offset": 47
 }
 },
 "@role": [
 "Expression",
 "Binary"
 ],
 "@type": "BinOp",
 "left":{
 "@pos":{
 "@type": "uast:Positions",
 "end":{
 "@type": "uast:Position",
 "col": 10,
 "line": 5,
 "offset": 48
 },
 "start":{
 "@type": "uast:Position",
 "col": 9,
 "line": 5,
 "offset": 47
 }
 },
 "@role": [
 "Identifier",
 "Expression",
 "Binary",
 "Left"
 ],
 "@token": "a",
 "@type": "Name",
 "ctx": "Load"
 },
 "op":{
 "@pos":{
 "@type": "uast:Positions"
 },
 "@role": [
 "Operator",
 "Arithmetic",
 "Add",
 "Binary"
 ],
 "@token": "+",
 "@type": "Add"
 },
 "right":{
 "@pos":{
 "@type": "uast:Positions",
 "end":{
 "@type": "uast:Position",
 "col": 14,
 "line": 5,
 "offset": 52
 },
 "start":{
 "@type": "uast:Position",
 "col": 13,
 "line": 5,
 "offset": 51
 }
 },
 "@role": [
 "Identifier",
 "Expression",
 "Binary",
 "Right"
 ],
 "@token": "b",
 "@type": "Name",
 "ctx": "Load"
 }
 }
 }
 ]
 },
 "decorator_list":{
 "@role": [
 "Function",
 "Declaration",
 "Incomplete"
 ],
 "@type": "FunctionDef.decorators",
 "decorators": []
 },
 "returns": null
 },
{
 "@pos":{
 "@type": "uast:Positions",
 "end":{
 "@type": "uast:Position",
 "col": 10,
 "line": 5,
 "offset": 48
 },
 "start":{
 "@type": "uast:Position",
 "col": 9,
 "line": 5,
 "offset": 47
 }
 },
 "@role": [
 "Identifier",
 "Expression",
 "Binary",
 "Left"
 ],
 "@token": "a",
 "@type": "Name",
 "ctx": "Load"
 },
{
 "@pos":{
 "@type": "uast:Positions",
 "end":{
 "@type": "uast:Position",
 "col": 14,
 "line": 5,
 "offset": 52
 },
 "start":{
 "@type": "uast:Position",
 "col": 13,
 "line": 5,
 "offset": 51
 }
 },
 "@role": [
 "Identifier",
 "Expression",
 "Binary",
 "Right"
 ],
 "@token": "b",
 "@type": "Name",
 "ctx": "Load"
 },
{
 "@pos":{
 "@type": "uast:Positions",
 "end":{
 "@type": "uast:Position",
 "col": 10,
 "line": 7,
 "offset": 63
 },
 "start":{
 "@type": "uast:Position",
 "col": 7,
 "line": 7,
 "offset": 60
 }
 },
 "@role": [
 "Identifier",
 "Expression",
 "Call",
 "Callee"
 ],
 "@token": "sum",
 "@type": "Name",
 "ctx": "Load"
 },
{
 "@pos":{
 "@type": "uast:Positions",
 "end":{
 "@type": "uast:Position",
 "col": 6,
 "line": 7,
 "offset": 59
 },
 "start":{
 "@type": "uast:Position",
 "col": 1,
 "line": 7,
 "offset": 54
 }
 },
 "@role": [
 "Identifier",
 "Expression",
 "Call",
 "Callee"
 ],
 "@token": "print",
 "@type": "Name",
 "ctx": "Load",
 "noops_previous":{
 "@pos":{
 "@type": "uast:Positions",
 "end":{
 "@type": "uast:Position",
 "col": 1,
 "line": 6,
 "offset": 53
 },
 "start":{
 "@type": "uast:Position",
 "col": 1,
 "line": 6,
 "offset": 53
 }
 },
 "@role": [
 "Noop"
 ],
 "@type": "PreviousNoops",
 "lines": []
 }
 }
]

[erizocosmico]

Same as we're retuning now, right? As for the syntax, maybe jsonpath? we already use it in JSON_EXTRACT UDF.

[kuba--]

@erizocosmico - this is what we get from bblfsh (whole node) converted to json. But the question is about extract. So far, extract returns a slice of all extracted sub-node values, e.g.:

["FunctionDef","Name","Name","Name","Name"]

["sum","a","b","sum","print"]

[["Function","Declaration","Name","Identifier"],["Identifier","Expression","Binary","Left"],["Identifier","Expression","Binary","Right"],["Identifier","Expression","Call","Callee"],["Identifier","Expression","Call","Callee"]]

[erizocosmico]

@ajnavarro what shall we do with this?

[ajnavarro]

I would leave it here just to have it in mind.