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| <td width="85%"> <font size="6" face="Verdana, Arial, Helvetica, sans-serif"><b>Organization</b></font> |
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| <td width="112"><a href="http://spirit.sf.net"><img src="theme/spirit.gif" width="112" height="48" align="right" border="0"></a></td> |
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| <p>The framework is highly modular and is organized in layers:</p> |
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| <td><div align="center"><font color="#003366"><strong>iterator</strong></font></div></td> |
| <td><div align="center"><font color="#003366"><strong>actor</strong></font></div></td> |
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| <font color="#003366" size="3"><br> |
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| <td><div align="center"><font color="#003366"><strong>debug</strong></font></div></td> |
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| <font color="#003366" size="3"><br> |
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| <td><div align="center"><font color="#003366"><strong>attribute</strong></font></div></td> |
| <td><div align="center"><font color="#003366"><strong>dynamic</strong></font></div></td> |
| <td><div align="center"><font color="#003366"><strong>error_handling</strong></font></div></td> |
| <td><div align="center"><font color="#003366"><strong>symbols</strong></font></div></td> |
| <td><div align="center"><font color="#003366"><strong>tree</strong></font></div></td> |
| <td><div align="center"><font color="#003366"><strong>utility</strong></font></div></td> |
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| <font color="#003366" size="3"><br> |
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| <td><div align="center"><font color="#003366"><strong>meta</strong></font></div></td> |
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| <font color="#003366"><br> |
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| <td colspan="4"><div align="center"><font color="#003366"><strong><font size="4">core</font></strong></font></div></td> |
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| <td><div align="center"><font color="#003366"><strong>scanner</strong></font></div></td> |
| <td><div align="center"><font color="#003366"><strong>primitives</strong></font></div></td> |
| <td><div align="center"><font color="#003366"><strong>composite</strong></font></div></td> |
| <td><div align="center"><font color="#003366"><strong>non_terminal</strong></font></div></td> |
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| <p>Spirit has four layers, plus an independent top layer. The independent layer, |
| comprising of actor and iterator, does not rely on the other layers. The framework's |
| architecture is completely orthogonal. The relationship among the layers is |
| acyclic. Lower layers do not depend nor know the existence of upper layers. |
| Modules in a layer do not depend on other modules in the same layer. </p> |
| <p>The client may use only the modules that she wants without incurring any compile |
| time nor run time penalty. A minimalistic approach is to use only the core as |
| is. The highly streamlined core is usable by itself. The core is sufficiently |
| suitable for tasks such as micro parsing.</p> |
| <p>The <strong>iterator</strong> module is independent of Spirit and may be used |
| in other non-Spirit applications. This module is a compilation of stand-alone |
| iterators and iterator wrappers compatible with Spirit. |
| |
| |
| Over time, these iterators have been found to be most useful for parsing with Spirit. </p> |
| <p>The <strong>actor</strong> module, also independent of Spirit, is a compilation |
| of predefined semantic actions that covers the most common semantics processing |
| tasks.</p> |
| <p>The <strong>debug</strong> module provides library wide parser debugging. This |
| module hooks itself up transparently into the core non-intrusively and only |
| when necessary.</p> |
| <p>The<strong> attribute</strong> module introduces advanced semantic action machinery |
| with emphasis on extraction and passing of data up and down the parser hierarchy |
| through inherited and synthesized attributes. Attributes may also be used to |
| actually control the parsing. Parametric parsers are a form of dynamic parsers |
| that changes their behavior at run time based on some attribute or data.</p> |
| <p>The <strong>dynamic</strong> module focuses on parsers with behavior that can |
| be modified at run-time.</p> |
| <p><strong>error_handling</strong>. The framework would not be complete without |
| Error Handling. C++'s exception handling mechanism is a perfect match for Spirit |
| due to its highly recursive functional nature. C++ Exceptions are used extensively |
| by this module for handling errors.</p> |
| <p>The<strong> symbols</strong> module focuses on symbol table management. This module |
| is rather basic now. The goal is to build a sub-framework that will be able |
| to accommodate C++ style multiple scope mechanisms. C++ is a great model for |
| the complexity of scoping that perhaps has no parallel in any other language. |
| There are classes and inheritance, private, protected and public access restrictions, |
| friends, namespaces, using declarations, using directives, Koenig lookup (Argument |
| Dependent Lookup) and more. The symbol table functionality we have now will |
| be the basis of a complete facility that will attempt to model this.</p> |
| <blockquote> |
| <p><em><font color="#003366">I wish that I could ever see, a structure as lovely |
| as a tree</font></em><font color="#003366">...</font></p> |
| </blockquote> |
| <p> Parse Tree and Abstract Syntax Tree (AST) generation are handled by the <b>Tree</b> |
| module. There are advantages with Parse Trees and Abstract Syntax Trees over |
| semantic actions. You can make multiple passes over the data without having |
| to re-parse the input. You can perform transformations on the tree. You can |
| evaluate things in any order you want, whereas with attribute schemes you have |
| to process in a begin to end fashion. You do not have to worry about backtracking |
| and action side effects that may occur with an ambiguous grammar.</p> |
| <p>The <b>utility</b> module is a set of commonly useful parsers and support classes |
| that were found to be useful in handling common tasks such as list processing, |
| comments, confix expressions, etc.</p> |
| <p><strong>meta</strong>, provides metaprogramming facilities for advanced Spirit |
| developers. This module facilitates compile-time and run-time introspection |
| of Spirit parsers.</p> |
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| <p class="copyright">Copyright © 1998-2003 Joel de Guzman<br> |
| <br> |
| <font size="2">Use, modification and distribution is subject to the Boost Software |
| License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
| http://www.boost.org/LICENSE_1_0.txt)</font></p> |
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