Etudes for ClojureScript

Chapter 4. Maps

In this chapter, you will work with maps (not to be confused with the map function, though you can use map on a map). Also, the études are designed to run on the server side with Node.js®, so you may want to see how to set that up in Appendix D.

Étude 4-1: Condiments

If you spend some time going through open datasets such as those from data.gov, you will find some fairly, shall we say, esoteric data. Among them is MyPyramid Food Raw Data from the Food and Nutrition Service of the United States Department of Agriculture.

One of the files is Foods_Needing_Condiments_Table.xml, which gives a list of foods and condiments that go with them. Here is what part of the file looks like, indented and edited to eliminate unnecessary elements, and placed in a file named test.xml:

<Foods_Needing_Condiments_Table> <Foods_Needing_Condiments_Row> <Survey_Food_Code>51208000</Survey_Food_Code> <display_name>100% Whole Wheat Bagel</display_name> <cond_1_name>Butter</cond_1_name> <cond_2_name>Tub margarine</cond_2_name> <cond_3_name>Reduced calorie spread (margarine type)</cond_3_name> <cond_4_name>Cream cheese (regular)</cond_4_name> <cond_5_name>Low fat cream cheese</cond_5_name> </Foods_Needing_Condiments_Row> <Foods_Needing_Condiments_Row> <Survey_Food_Code>58100100</Survey_Food_Code> <display_name>"Beef burrito (no beans):"</display_name> <cond_1_name>Sour cream</cond_1_name> <cond_2_name>Guacamole</cond_2_name> <cond_3_name>Salsa</cond_3_name> </Foods_Needing_Condiments_Row> ...