Concepts of Programming Languages

1.7 Implementation Methods 29

1.7.3 Hybrid Implementation Systems

Some language implementation systems are a compromise between compilers

and pure interpreters; they translate high-level language programs to an inter-

mediate language designed to allow easy interpretation. This method is faster

than pure interpretation because the source language statements are decoded

only once. Such implementations are called hybrid implementation systems.

The process used in a hybrid implementation system is shown in

Figure 1.5. Instead of translating intermediate language code to machine

code, it simply interprets the intermediate code.

Source

program

Interpreter

Results

Input data

Lexical

analyzer

Syntax

analyzer

Intermediate

code generator

Parse trees

Lexical units

Intermediate

code

Figure 1.5

Hybrid implementation
system