Merge pull request #6 from DannyBen/add/hash-row-access

Add support for accessing rows by `table[colname: value]`

Runfile

@@ -1,8 +1,9 @@
-require "byebug"
-require "lp"
+require 'byebug'
+require 'lp'
+require 'true_table'
 
-title   "TrueTable Developer Toolbelt"
-summary "Runfile tasks for building the TrueTable gem"
+title   'TrueTable Developer Toolbelt'
+summary 'Runfile tasks for building the TrueTable gem'
 
 import_gem 'runfile-tasks/gem'
 import_gem 'runfile-tasks/yard'

lib/true_table.rb

@@ -51,12 +51,20 @@ def -(other)
 
   # Returns a row or a column
   def [](key)
-    key.is_a?(Symbol) ? col(key) : super
+    case key
+    when Symbol then col(key)
+    when Hash   then row(key)
+    else super
+    end
   end
 
   # Adds or updates a row or a column
   def []=(key, value)
-    key.is_a?(Symbol) ? add_col(key.to_sym, value) : super
+    case key
+    when Symbol then add_col(key.to_sym, value)
+    when Hash   then add_row(key, value)
+    else super
+    end
   end
 
   # Returns a deep copy of self
@@ -134,19 +142,29 @@ def each_col
   # Iterates over rows
   alias each_row each_with_index
 
+  # Returns a row or a column
   def fetch(key, *default)
-    if key.is_a?(Symbol)
-      if headers.include? key
-        col(key.to_sym)
-      elsif default.any?
-        default.first
-      elsif block_given?
-        yield key
+    case key
+    when Symbol
+      if headers.include?(key) then col(key.to_sym)
+      elsif default.any? then default.first
+      elsif block_given? then yield key
       else
-        raise IndexError, "row :#{key} does not exist"
+        raise IndexError, "col :#{key} does not exist"
       end
+
+    when Hash
+      result = row(key)
+      if result then result
+      elsif default.any? then default.first
+      elsif block_given? then yield key
+      else
+        raise IndexError, "row #{key} does not exist"
+      end
+
     else
       super
+
     end
   end
 
@@ -155,6 +173,11 @@ def headers
     first.keys
   end
 
+  # Returns a short inspection string
+  def inspect
+    "<#{self.class}:#{object_id} size=#{size} headers=#{headers}>"
+  end
+
   # Returns a new table with intersecting rows
   def intersection(*others)
     self.class.new super
@@ -191,7 +214,12 @@ def rotate(count = 1)
   end
 
   # Returns a row
-  alias row []
+  def row(key)
+    key.is_a?(Hash) ? find { |x| x[key.first.first] == key.first.last } : self[key]
+  end
+
+  # Returns all rows
+  alias rows to_a
 
   # Saves the table as a CSV file
   def save_csv(path)
@@ -286,4 +314,8 @@ def add_col(key, values)
       self[i][key] = value
     end
   end
+
+  def add_row(key, values)
+    row(key).merge! values
+  end
 end

spec/true_table/true_table_spec.rb

@@ -86,6 +86,12 @@
         expect(subject[:population][3]).to eq 2
       end
     end
+
+    context 'with a hash key' do
+      it 'returns a row' do
+        expect(subject[year: 2023][:population]).to eq 2
+      end
+    end
   end
 
   describe '#[]=' do
@@ -102,6 +108,13 @@
         expect(subject[1]).to eq({ population: 20_000, year: 2021, infected: 1_980_000 })
       end
     end
+
+    context 'with a hash key' do
+      it 'adds the row' do
+        subject[year: 2023] = { population: 23 }
+        expect(subject[:population]).to eq [2_000_000, 20_000, 200, 23]
+      end
+    end
   end
 
   describe '#clone' do
@@ -439,9 +452,7 @@
 
   describe '#minmax' do
     it 'returns a two element array with min and max rows' do
-      result = subject.minmax do |a, b|
-        a[:population] <=> b[:population]
-      end
+      result = subject.minmax_by { |a| a[:population] }
       expect(result[0][:year]).to eq 2023
       expect(result[1][:year]).to eq 2020
     end
@@ -527,6 +538,20 @@
     end
   end
 
+  describe '#row' do
+    context 'with an integer key' do
+      it 'returns a row' do
+        expect(subject[2][:population]).to eq 200
+      end
+    end
+
+    context 'with a hash key' do
+      it 'returns a row' do
+        expect(subject[year: 2023][:population]).to eq 2
+      end
+    end
+  end
+
   describe '#rotate' do
     it 'offsets the rows to the top' do
       expect(subject.rotate(2)[0][:year]).to eq 2022
@@ -654,7 +679,7 @@
 
   describe '#sort!' do
     it 'sorts the table in place' do
-      subject.sort! { |a, b| a[:population] <=> b[:population] }
+      subject.sort_by! { |a| a[:population] }
 
       expect(subject[0][:population]).to eq 2
       expect(subject[3][:population]).to eq 2_000_000