A method and system is provided that allows a well-behaved program to execute more quickly than dynamically typed programming languages did in the past, thereby allowing a the dynamically typed language to be competitive with static declarative programming languages. A method includes converting lines of source code representing functions to byte-codes representing functions, selecting a subsequence of the byte-codes based on the byte-codes and the dynamic run-time properties of program variables, generating processor instructions in a compiler for the subsequence, and interpreting the byte-codes not contained in the subsequence.