Do Standard.Table.Data.Table

distribution/std-lib/Standard/data/food_shop_inventory.csv

@@ -1,10 +1,10 @@
-item_name                  , price , stock
-Pavlova Cake (Whole)       , 10.50 , 10
-Gruyere (Wheel)            , 50    , 3
-Strawberries (Punnett)     , 4.50  , 50
-Tomatoes (Whole)           , 0.5   , 100
-Tomato and Egg Sandwich    , 1.75  , 20
-Lobster Thermidor          , 15.50 , 10
-Syrniki                    , 1.99  , 25
-Bacon and Sausage Sandwich , 1.75  , 15
+item_id , item_name                  , price , total_stock , sold_stock
+001     , Pavlova Cake (Whole)       , 10.50 , 10          , 7
+002     , Gruyere (Wheel)            , 50    , 3           , 1
+003     , Strawberries (Punnett)     , 4.50  , 50          , 47
+004     , Tomatoes (Whole)           , 0.5   , 100         , 32
+005     , Tomato and Egg Sandwich    , 1.75  , 20          , 7
+006     , Lobster Thermidor          , 15.50 , 10          , 9
+007     , Syrniki                    , 1.99  , 25          , 11
+008     , Bacon and Sausage Sandwich , 1.75  , 15          , 12
 

distribution/std-lib/Standard/data/food_shop_popularity.csv

@@ -0,0 +1,9 @@
+item_id , popularity
+001     , 5
+002     , 2
+003     , 5
+004     , 3
+005     , 1
+006     , 2
+007     , 3
+008     , 4

distribution/std-lib/Standard/data/food_shop_transactions.csv

@@ -0,0 +1,13 @@
+transaction_id , item_id , quantity
+001            , 001     , 1
+001            , 008     , 2
+002            , 005     , 4
+003            , 003     , 2
+003            , 004     , 1
+003            , 007     , 8
+004            , 002     , 1
+005            , 006     , 2
+006            , 001     , 1
+007            , 005     , 2
+008            , 003     , 5
+

distribution/std-lib/Standard/src/Examples.enso

@@ -15,25 +15,6 @@ import Standard.Base.Network.Uri as Enso_Uri
 import Standard.Image as Enso_Image
 import Standard.Image.Data.Matrix as Enso_Matrix
 
-# Can do the top-level examples directory.
-
-# Fine to not provide examples for some APIs (e.g. Database).
-
-# Examples with HTTP should note this clearly in the example text.
-
-# Image source should only download if it doesn't exist. We can say that the #
-# user can put it there.
-
-# > Example
-#   Frobnicate the doobly do
-#
-#       import Standard.Examples
-#
-#       my_example =
-#           x = dlksaldjks
-#           y = x + 1
-#           ...
-
 ## An example error type used in a number of examples.
 
    Arguments:
@@ -247,3 +228,31 @@ text_column_2 = Table.Column.from_vector "Text" ["He,", "he", "he", "i", "so"]
 
 ## A simple aggregate column.
 aggregate_column : Table.Column.Aggregate_Column
+
+## A simple table that contains basic shop inventory data for the food shop.
+inventory_table : Table.Table
+inventory_table = Table.from_csv here.csv . set_index "item_id"
+
+## A simple table that contains basic item popularity data for the food shop.
+popularity_table : Table.Table
+popularity_table =
+    table = Table.from_csv <| Enso_Project.data / "food_shop_popularity.csv"
+    table.set_index "item_id"
+
+## A simple tablethat contains basic transaction data for the food shop.
+transactions_table : Table.Table
+transactions_table =
+    Table.from_csv <| Enso_Project.data / "food_shop_transactions.csv"
+
+## An aggregate table for the relevant examples.
+aggregate_table : Table.Aggregate_Table
+aggregate_table =
+    transactions = Examples.transactions_table
+    item_names = Examples.inventory_table.at "item_name"
+    with_names = transactions.join item_names on="item_id"
+    with_names.group by="item_name"
+
+## An aggregate column for the relevant examples.
+aggregate_column : Table.Column.Aggregate_Column
+aggregate_column = here.aggregate_table.at "transaction_id"
+

distribution/std-lib/Standard/src/Table/Data/Column.enso

@@ -1032,6 +1032,15 @@ type Aggregate_Column
          groups.
        - name_suffix: a suffix that will be appended to the original column name
          to generate the resulting column name.
+
+       > Example
+         Convert an aggregate column of transaction ids into a column by
+         counting the number of transactions. per item.
+
+             import Standard.Examples
+
+             example_reduce =
+                 Examples.aggregate_column.reduce .length . rename "transaction_count"
     reduce : (Vector.Vector -> Any) -> Boolean -> Text -> Column
     reduce function skip_missing=True name_suffix="_result" =
         f arr = function (Vector.Vector arr)
@@ -1043,6 +1052,14 @@ type Aggregate_Column
        Arguments:
        - name_suffix: a suffix that will be appended to the original column name
          to generate the resulting column name.
+
+       > Example
+         Convert an aggregate column of transaction ids into a column by summing
+         the transaction IDs together.
+
+             import Standard.Examples
+
+             example_sum = Examples.aggregate_column.sum . rename "id_sum"
     sum : Text -> Column
     sum name_suffix='_sum' =
         r = this.java_column.aggregate 'sum' name_suffix (x-> Vector.Vector x . reduce (+)) True
@@ -1053,6 +1070,13 @@ type Aggregate_Column
        Arguments:
        - name_suffix: a suffix that will be appended to the original column name
          to generate the resulting column name.
+
+       > Example
+         Get the latest (maximum ID) transaction id for each item.
+
+             import Standard.Examples
+
+             example_max = Examples.aggregate_column.max . rename "latest_transaction"
     max : Text -> Column
     max name_suffix='_max' =
         r = this.java_column.aggregate 'max' name_suffix (x-> Vector.Vector x . reduce Math.max) True
@@ -1063,6 +1087,13 @@ type Aggregate_Column
        Arguments:
        - name_suffix: a suffix that will be appended to the original column name
          to generate the resulting column name.
+
+       > Example
+         Get the earliest (mimumum ID) transaction id for each item.
+
+             import Standard.Examples
+
+             example_min = Examples.aggregate_column.min . rename "first_transaction"
     min : Text -> Column
     min name_suffix='_min' =
         r = this.java_column.aggregate 'min' name_suffix (x-> Vector.Vector x . reduce Math.min) True
@@ -1073,6 +1104,14 @@ type Aggregate_Column
        Arguments:
        - name_suffix: a suffix that will be appended to the original column name
          to generate the resulting column name.
+
+       > Example
+         Count the number of non-missing elements in each group in the column,
+         which gives the number of transactions in which a given item was sold.
+
+             import Standard.Examples
+
+             example_count = Examples.aggregate_column.count . rename "transaction_count"
     count : Text -> Column
     count name_suffix='_count' =
         r = this.java_column.aggregate 'count' name_suffix (x-> x.length) True
@@ -1083,6 +1122,13 @@ type Aggregate_Column
        Arguments:
        - name_suffix: a suffix that will be appended to the original column name
          to generate the resulting column name.
+
+       > Example
+         Get the mean transaction id for each item.
+
+             import Standard.Examples
+
+             example_mean = Examples.aggregate_column.mean
     mean : Text -> Column
     mean name_suffix='_mean' =
         vec_mean v = if v.length == 0 then Nothing else
@@ -1096,11 +1142,33 @@ type Aggregate_Column
        Arguments:
        - name_suffix: a suffix that will be appended to the original column name
          to generate the resulting column name.
+
+       > Example
+         Gather the values of the aggregate column together.
+
+             import Standard.Examples
+
+             example_values = Examples.aggregate_column.values
     values : Text -> Column
     values name_suffix='_values' =
         r = this.java_column.aggregate Nothing name_suffix Vector.Vector False
         Column r
 
+    ## Prints an ASCII-art column with this data to the standard output.
+
+       Arguments:
+       - show_rows: the number of initial rows that should be displayed.
+
+       > Example
+         Pretty-print an aggregate column and display it using the standard
+         output.
+
+             import Standard.Examples
+
+             example_print = Examples.aggregate_column.print
+    print : Nothing
+    print = this.values.print
+
 ## UNSTABLE
 
    A type representing an error for an out-of-bounds index in a column.