A domain-specific language interpreter and live updating visual interface for rapid interactive exploration, filtering, and analysis of a dynamic data set. It includes a multi-line editor that allows a user to enter and edit input on any line at any time, and a grid view display. As the user enters an expression in the multi-line editor, it continually parses and executes the expression with respect to the domain-specific language, recognizing data tags and operations. Each data tag is associated with values for identifiers of the data set, and each operation can be applied to the values. The grid view display updates with a live display of identifiers and result values for the input expression according to the current contents of the multi-line editor user input interface.