Convert plain text with a specific format into JSON in VIM - json

Question

All my university notes are in JSON format and when I get a set of practical questions from a pdf it is formatted like this:
1. Download and compile the code. Run the example to get an understanding of how it works. (Note that both
threads write to the standard output, and so there is some mixing up of the two conceptual streams, but this
is an interface issue, not of concern in this course.)
2. Explore the classes SumTask and StringTask as well as the abstract class Task.
3. Modify StringTask.java so that it also writes out “Executing a StringTask task” when the execute() method is
called.
4. Create a new subclass of Task called ProdTask that prints out the product of a small array of int. (You will have
to add another option in TaskGenerationThread.java to allow the user to generate a ProdTask for the queue.)
Note: you might notice strange behaviour with a naïve implementation of this and an array of int that is larger
than 7 items with numbers varying between 0 (inclusive) and 20 (exclusive); see ProdTask.java in the answer
for a discussion.
5. Play with the behaviour of the processing thread so that it polls more frequently and a larger number of times,
but “pop()”s off only the first task in the queue and executes it.
6. Remove the “taskType” member variable definition from the abstract Task class. Then add statements such as
the following to the SumTask class definition:
private static final String taskType = "SumTask";
Investigate what “static” and “final” mean.
7. More challenging: write an interface and modify the SumTask, StringTask and ProdTask classes so that they
implement this interface. Here’s an example interface:
What I would like to do is copy it into vim and execute a find and replace to convert it into this:
"1": {
"Task": "Download and compile the code. Run the example to get an understanding of how it works. (Note that both threads write to the standard output, and so there is some mixing up of the two conceptual streams, but this is an interface issue, not of concern in this course.)",
"Solution": ""
},
"2": {
"Task": "Explore the classes SumTask and StringTask as well as the abstract class Task.",
"Solution": ""
},
"3": {
"Task": "Modify StringTask.java so that it also writes out “Executing a StringTask task” when the execute() method is called.",
"Solution": ""
},
"4": {
"Task": "Create a new subclass of Task called ProdTask that prints out the product of a small array of int. (You will have to add another option in TaskGenerationThread.java to allow the user to generate a ProdTask for the queue.) Note: you might notice strange behaviour with a naïve implementation of this and an array of int that is larger than 7 items with numbers varying between 0 (inclusive) and 20 (exclusive); see ProdTask.java in the answer for a discussion.",
"Solution": ""
},
"5": {
"Task": "Play with the behaviour of the processing thread so that it polls more frequently and a larger number of times, but “pop()”s off only the first task in the queue and executes it.",
"Solution": ""
},
"6": {
"Task": "Remove the “taskType” member variable definition from the abstract Task class. Then add statements such as the following to the SumTask class definition: private static final String taskType = 'SumTask'; Investigate what “static” and “final” mean.",
"Solution": ""
},
"7": {
"Task": "More challenging: write an interface and modify the SumTask, StringTask and ProdTask classes so that they implement this interface. Here’s an example interface:",
"Solution": ""
}
After trying to figure this out during the practical (instead of actually doing the practical) this is the closest I got:
%s/\([1-9][1-9]*\)\. \(\_.\{-}\)--end--/"\1": {\r "Task": "\2",\r"Solution": "" \r},/g
The 3 problems with this are
I have to add --end-- to the end of each question. I would like it to know when the question ends by looking ahead to a line which starts with [1-9][1-9]*. unfortunately when I search for that It also replaces that part.
This keeps all the new lines within the question (which is invalid in JSON). I would like it to remove the new lines.
The last entry should not contain a "," after the input because that would also be invalid JSON (Note I don't mind this very much as it is easy to remove the last "," manually)
Please keep in mind I am very bad at regular expressions and one of the reasons I am doing this is to learn more about regex so please explain any regex you post as a solution.

Answer 1

In two steps:
%s/\n/\ /g
to solve problem 2, and then:
%s/\([1-9][1-9]*\)\. \(\_.\{-}\([1-9][1-9]*\. \|\%$\)\#=\)/"\1": {\r "Task": "\2",\r"Solution": "" \r},\r/g
to solve problem 1.
You can solve problem 3 with another replace round. Also, my solution inserts an unwanted extra space at the end of the task entries. Try to remove it yourself.
Short explanation of what I have added:
\|: or;
\%$: end of file;
\#=: find but don't include in match.

Answer 2

If each item sits in single line, I would transform the text with macro, it is shorter and more straightforward than the :s:
I"<esc>f.s": {<enter>"Task": "<esc>A"<enter>"Solution": ""<enter>},<esc>+
Record this macro in a register, like q, then you can just replay it like 100#q to do the transformation.
Note that
the result will leave a comma , and the end, just remove it.
You can also add indentations during your macro recording, then your json will be "pretty printed". Or you can make it sexy later with other tool.

Answer 3

You could probably do this with one large regular expression, but that quickly becomes unmaintainable. I would break the task up into 3 steps instead:
Separate each numbered step into its own paragraph .
Put each paragraph on its own line .
Generate the JSON .
Taken together:
%s/^[0-9]\+\./\r&/
%s/\(\S\)\n\(\S\)/\1 \2/
%s/^\([0-9]\+\)\. *\(.*\)/"\1": {\r "Task": "\2",\r "Solution": ""\r},/
This solution also leaves a comma after the last element. This can be removed with:
$s/,//
Explanation
%s/^[0-9]\+\./\r&/ this matches a line starting with a number followed by a dot, e.g. 1., 8., 13., 131, etc. and replaces it with a newline (\r) followed by the match (&).
%s/\(\S\)\n\(\S\)/\1 \2/ this removes any newline that is flanked by non-white-space characters (\S).
%s/^\([0-9]\+\)\. *\(.*\) ... capture the number and text in \1 and \2.
... /"\1": {\r "Task": "\2",\r "Solution": ""\r},/ format text appropriately.
Alternative way using sed, awk and jq
You can perform steps one and two from above straightforwardly with sed and awk:
sed 's/^[0-9]\+\./\n&/' infile
awk '$1=$1; { print "\n" }' RS= ORS=' '
Using jq for the third step ensures that the output is valid JSON:
jq -R 'match("([0-9]+). *(.*)") | .captures | {(.[0].string): { "Task": (.[1].string), "Solution": "" } }'
Here as one command line:
sed 's/^[0-9]\+\./\n&/' infile |
awk '$1=$1; { print "\n" }' RS= ORS=' ' |
jq -R 'match("([0-9]+). *(.*)") | .captures | {(.[0].string): { "Task": (.[1].string), "Solution": "" } }'