From 442bf3cde3e4dc587ae564586b6728399aa850a4 Mon Sep 17 00:00:00 2001
From: Chris Watson <chris@watzon.me>
Date: Mon, 17 Jun 2019 23:18:45 -0700
Subject: [PATCH] Added to_json and from_json to Matrix and Vector

---
 src/apatite/linear_algebra/matrix.cr | 22 ++++++++++++++++++++
 src/apatite/linear_algebra/vector.cr | 31 ++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/src/apatite/linear_algebra/matrix.cr b/src/apatite/linear_algebra/matrix.cr
index 96c67f1..9cc4bd8 100644
--- a/src/apatite/linear_algebra/matrix.cr
+++ b/src/apatite/linear_algebra/matrix.cr
@@ -1,3 +1,4 @@
+require "json"
 require "./vector"
 
 module Apatite::LinearAlgebra
@@ -18,6 +19,21 @@ module Apatite::LinearAlgebra
       @column_count = column_count || rows[0].size
     end
 
+    # Creates a new `Vector` instance from a `JSON::PullParser`
+    def self.new(pull : JSON::PullParser)
+      arr = [] of Vector
+      new(pull) do |element|
+        arr << element
+      end
+      rows(arr)
+    end
+
+    def self.new(pull : JSON::PullParser, &block)
+      pull.read_array do
+        yield Vector.new(pull)
+      end
+    end
+
     # Creates a matrix where each argument is a row.
     def self.[](*rows)
       rows(rows)
@@ -528,6 +544,12 @@ module Apatite::LinearAlgebra
       end
     end
 
+    def to_json(json : JSON::Builder)
+      json.array do
+        each &.to_json(json)
+      end
+    end
+
     @[AlwaysInline]
     def unsafe_fetch(index : Int)
       @buffer[index]
diff --git a/src/apatite/linear_algebra/vector.cr b/src/apatite/linear_algebra/vector.cr
index 0673b79..ca2271b 100644
--- a/src/apatite/linear_algebra/vector.cr
+++ b/src/apatite/linear_algebra/vector.cr
@@ -1,3 +1,5 @@
+require "json"
+
 module Apatite::LinearAlgebra
   # Represents a mathematical vector, and also constitutes a row or column
   # of a `Matrix`
@@ -75,6 +77,21 @@ module Apatite::LinearAlgebra
       end
     end
 
+    # Creates a new `Vector` instance from a `JSON::PullParser`
+    def self.new(pull : JSON::PullParser)
+      vec = new
+      new(pull) do |element|
+        vec << element
+      end
+      vec
+    end
+
+    def self.new(pull : JSON::PullParser, &block)
+      pull.read_array do
+        yield Float64.new(pull)
+      end
+    end
+
     # Creates a new `Vector` of the given *size* and invokes the given block once
     # for each index of `self`, assigning the block's value in that index.
     #
@@ -742,6 +759,20 @@ module Apatite::LinearAlgebra
       io << "}"
     end
 
+    def to_json(json : JSON::Builder)
+      json.array do
+        each &.to_json(json)
+      end
+    end
+
+    def from_json(string_or_io)
+      parser = JSON::PullParser.new(string_or_io)
+      new(parser) do |element|
+        yield element
+      end
+      nil
+    end
+
     def pretty_print(pp) : Nil
       pp.list("Vector{", self, "}")
     end