[![Build Status](https://travis-ci.org/timo/json_fast.svg?branch=master)](https://travis-ci.org/timo/json_fast) JSON::Fast ========== A naive imperative JSON parser in pure Raku (but with direct access to `nqp::` ops), to evaluate performance against `JSON::Tiny`. It is a drop-in replacement for `JSON::Tiny`’s from-json and to-json subs, but it offers a few extra features. Currently it seems to be about 4x faster and uses up about a quarter of the RAM JSON::Tiny would use. This module also includes a very fast to-json function that tony-o created and lizmat later completely refactored. Exported subroutines -------------------- ### to-json my $*JSON_NAN_INF_SUPPORT = 1; # allow NaN, Inf, and -Inf to be serialized. say to-json []; say to-json [], :!pretty; say to-json [], :spacing(4); enum Blerp ; say to-json [Hello, Goodbye]; # ["Hello", "Goodbye"] say to-json [Hello, Goodbye], :enums-as-value; # [0, 1] Encode a Raku data structure into JSON. Takes one positional argument, which is a thing you want to encode into JSON. Takes these optional named arguments: #### pretty `Bool`. Defaults to `True`. Specifies whether the output should be "pretty", human-readable JSON. When set to false, will output json in a single line. #### spacing `Int`. Defaults to `2`. Applies only when `pretty` is `True`. Controls how much spacing there is between each nested level of the output. #### sorted-keys `Bool`, defaults to `False`. Specifies whether keys from objects should be sorted before serializing them to a string or if `$obj.keys` is good enough. #### enum-as-value `Bool`, defaults to `False`. Specifies whether `enum`s should be json-ified as their underlying values, instead of as the name of the `enum`. ### from-json my $x = from-json '["foo", "bar", {"ber": "bor"}]'; say $x.perl; # outputs: $["foo", "bar", {:ber("bor")}] Takes one positional argument that is coerced into a `Str` type and represents a JSON text to decode. Returns a Raku datastructure representing that JSON. #### immutable `Bool`. Defaults to `False`. Specifies whether `Hash`es and `Array`s should be rendered as immutable datastructures instead (as `Map` / `List`. Creating an immutable data structures is mostly saving on memory usage, and a little bit on CPU (typically around 5%). This also has the side effect that elements from the returned structure can now be iterated over directly because they are not containerized. my %hash := from-json "META6.json".IO.slurp, :immutable; say "Provides:"; .say for %hash; Additional features ------------------- ### Adapting defaults of "from-json" In the `use` statement, you can add the string `"immutable"` to make the default of the `immutable` parameter to the `from-json` subroutine `True`, rather than False. use JSON::Fast ; # create immutable data structures by default ### Adapting defaults of "to-json" In the `use` statement, you can add the strings `"!pretty"`, `"sorted-keys"` and/or `"enums-as-value"` to change the associated defaults of the `to-json` subroutine. use JSON::FAST ; ### Strings containing multiple json pieces When the document contains additional non-whitespace after the first successfully parsed JSON object, JSON::Fast will throw the exception `X::JSON::AdditionalContent`. If you expect multiple objects, you can catch that exception, retrieve the parse result from its `parsed` attribute, and remove the first `rest-position` characters off of the string and restart parsing from there.