1. A non-transitory computer readable memory medium that stores program instructions for analyzing a graphical program, wherein the program instructions are executable by a processor to: display the graphical program on a display, wherein the graphical program comprises a plurality of interconnected nodes that visually indicate functionality of the graphical program; perform a semantic edit operation on the graphical program in response to user input, wherein the semantic edit operation is performed by a first process; perform semantic analysis of the graphical program in response to said performing the semantic edit operation, wherein the semantic analysis is performed by a second process, and wherein the second process is asynchronous with respect to the first process; display results from the semantic analysis of the graphical program in response to completion of the semantic analysis; and perform one or more times: during said performing the semantic analysis, perform another semantic edit operation on the graphical program in response to next user input, wherein the other semantic edit operation is performed by the first process; and in response to said performing the other semantic edit operation, preemptively terminate and re-initiate performing the semantic analysis with respect to the graphical program in the second process; wherein to display results from the semantic analysis of the graphical program in response to completion of the semantic analysis, the program instructions are executable to: display results from the re-initiated semantic analysis of the graphical program in response to completion of the re-initiated semantic analysis.