8. A method comprising: creating a data structure of real symbols representing source code generated by a background compiler during interactive program development in a programming environment, wherein a module executing on a computer adds at least one inferred symbol to the data structure during the interactive program development, wherein the at least one inferred symbol is based on source code entered in a source code editor wherein the at least one inferred symbol is inferred from the source code based on usage in the source code of an undefined symbol; during the interactive program development, utilizing the at least one inferred symbol in a tool that is part of the source code editor, wherein the tool displays the inferred symbol for the user's use in developing source code; and during the interactive program development, converting the inferred symbol into a real symbol in the data structure based on receiving user input indicating to perform the conversion.
8. A method comprising: creating a data structure of real symbols representing source code generated by a background compiler during interactive program development in a programming environment, wherein a module executing on a computer adds at least one inferred symbol to the data structure during the interactive program development, wherein the at least one inferred symbol is based on source code entered in a source code editor wherein the at least one inferred symbol is inferred from the source code based on usage in the source code of an undefined symbol; during the interactive program development, utilizing the at least one inferred symbol in a tool that is part of the source code editor, wherein the tool displays the inferred symbol for the user's use in developing source code; and during the interactive program development, converting the inferred symbol into a real symbol in the data structure based on receiving user input indicating to perform the conversion. 14. The method of claim 8 , further comprising: wherein conversion of the at least one inferred symbol to a real symbol triggers automatic compiler-generated addition of source code defining the at least one inferred symbol, wherein the source code defining the at least one inferred symbol is added to the source code in the source code editor.