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I’d really like a CLI tool which solves this problem using a syntax I already know. I struggle with jq because I use it quite infrequently. IMO the ideal solut

I’d really like a CLI tool which solves this problem using a syntax I already know. I struggle with jq because I use it quite infrequently. IMO the ideal solution is something using pure JavaScript syntax, possibly with a library resembling jQuery for tree traversal.

jolmg 7y ago
Most of jq's syntax is just a mix of JavaScript and a typical shell's. Every expression has an input and output like a shell command's stdin and stdout. Functions work on arguments and their stdin to produce their stdout. Here's an explanation of the syntax in the command I posted: jq ' # output the value at "Directory" from input object .Directory # pipe to map (JavaScript also has map()). The argument of map works in # the context of each element in map's input array. | map( # Produce an object where the property name is a string that # interpolates the value of the "name" property of this element. # Instead of interpolating, we could have also used this more # JavaScript-ish (ES5) syntax: # # {(.name + " has children"): ... # # The property value is an expression that gets the value of the # "children" property and pipes it to the expression `length != 0`. # `length` (which JavaScript also has) outputs the length of the # piped input, and then we compare that with 0. {"\(.name) has children": (.children | length != 0)} ) # map's output is a single record which is an array. We pipe that to # .[] to make multiple records, each an element of the array. The # syntax here is comprised of 2 parts: `.`, which is the input object, # and `[]` which is the subscript syntax without an index. | .[] ' > IMO the ideal solution is something using pure JavaScript syntax The greatest advantage of the current syntax is the great balance it has between legibility and terseness. I don't think making it pure JavaScript would be better. > possibly with a library resembling jQuery for tree traversal Using jQuery in JavaScript to traverse JavaScript objects? I don't know what to say...
- zeroimpl 7y ago
  Something like this would do the same, if somebody implemented a tool called jsed: jsed ' Object.fromEntries( $("Directory").map( x => [ x.name + " has children", x.children && x.children.length != 0 ] ) )' Interestingly enough there is already a tool called jsed which seems to kind of do this... https://www.npmjs.com/package/jsed https://www.npmjs.com/package/jsed Edit: Note the jQuery part of it is for advanced cases like searching for specific nodes in the tree, then navigating back up to the parent. Basically the cases like "<Work>[-1][children]" from the jtc guide, I would write as: '$("Work").parent().find("children")'

jolmg 7y ago

Most of jq's syntax is just a mix of JavaScript and a typical shell's. Every expression has an input and output like a shell command's stdin and stdout. Functions work on arguments and their stdin to produce their stdout. Here's an explanation of the syntax in the command I posted: jq ' # output the value at "Directory" from input object .Directory # pipe to map (JavaScript also has map()). The argument of map works in # the context of each element in map's input array. | map( # Produce an object where the property name is a string that # interpolates the value of the "name" property of this element. # Instead of interpolating, we could have also used this more # JavaScript-ish (ES5) syntax: # # {(.name + " has children"): ... # # The property value is an expression that gets the value of the # "children" property and pipes it to the expression `length != 0`. # `length` (which JavaScript also has) outputs the length of the # piped input, and then we compare that with 0. {"\(.name) has children": (.children | length != 0)} ) # map's output is a single record which is an array. We pipe that to # .[] to make multiple records, each an element of the array. The # syntax here is comprised of 2 parts: `.`, which is the input object, # and `[]` which is the subscript syntax without an index. | .[] ' > IMO the ideal solution is something using pure JavaScript syntax The greatest advantage of the current syntax is the great balance it has between legibility and terseness. I don't think making it pure JavaScript would be better. > possibly with a library resembling jQuery for tree traversal Using jQuery in JavaScript to traverse JavaScript objects? I don't know what to say...

zeroimpl 7y ago
Something like this would do the same, if somebody implemented a tool called jsed: jsed ' Object.fromEntries( $("Directory").map( x => [ x.name + " has children", x.children && x.children.length != 0 ] ) )' Interestingly enough there is already a tool called jsed which seems to kind of do this... https://www.npmjs.com/package/jsed https://www.npmjs.com/package/jsed Edit: Note the jQuery part of it is for advanced cases like searching for specific nodes in the tree, then navigating back up to the parent. Basically the cases like "<Work>[-1][children]" from the jtc guide, I would write as: '$("Work").parent().find("children")'