Partial parsing #88

For partial input parsing, we need to know when failure is caused by missing data so that we can retry parsing later when we have more data. This commit adds a need_data boolean flag alongs the failed one. It adds a stop function to set that flag and propagate the failure. It replaces checks for failure with a check on both failed and need_data flags. It also adds a eos function to check for end of input. It also replaces the fail calls due to end of input by stop calls.

As of now, the program stack is implicitly used to build the json object tree. For partial parsing support, we cannot use the program stack as parsing can be called at anytime. This commit adds a values stack and uses it to transmit value back along the object tree. All parsing functions now return void and instead pushes their result on the stack. The functions needing the result of other parsing functions (mostly for arrays and objects) read values from the stack and pop them.

As we now have an explicit stack, we don't need the depth variable argument to count the recursion levels. We can simply use the value stack size instead.

For partial support, when continuing parsing, we need to restart in the same state as we left. For that, we need to skip some actions if they were already done. Left as is, the code would be littered with ifs so refactor the parse_json function into multiple function, one per type of objects.

For partial parsing support, we need to remember what we were doing so that we can continue parsing. This commit adds an enum with all our parsing states and a states stack to store the current states.

For partial building, we need to temporary store the object being build as we maybe interrupted. This commits change object and array parsing to use the values stack has a temporary place for storing the object being build.

For parsing partial json, we need to be able to restart parsing from a valid position in the input stream. This commit stores the current position when switching state and restores it when more data is needed so that when parsing again, the parser restarts at the right position.

This commit implements a consume method that takes a chunk of json, append it to the current data and parses it.

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Partial parsing #88

Partial parsing #88

Commits on Jan 6, 2017

Partial parsing #88

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Partial parsing #88

Commits on Jan 6, 2017