The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
Workshop on Implementing Automata/Conference on Implementation and Application of Automata, 2001
A formal device is said to be adaptive whenever its behavior changes dynamically, in a direct res... more A formal device is said to be adaptive whenever its behavior changes dynamically, in a direct response to its input stimuli, without interference of external agents, even its users. In order to achieve this feature, adaptive devices have to be self-modifiable. In other words, any possible changes in the device’s behavior must be known at their full extent at any step of its operation in which the changes have to take place. Therefore, adaptive devices must be able to detect all situations causing possible modifications and to adequately react by imposing corresponding changes to the device’s behavior. In this work, devices are considered whose behavior is based on the operation of subjacent non-adaptive devices that be fully described by some finite set of rules. An adaptive rule-driven device may be obtained by attaching adaptive actions to the rules of the subjacent formulation, so that whenever a rule is applied, the associated adaptive action is activated, causing the set of rules of the subjacent non-adaptive device to be correspondingly changed. In this paper a new general formulation is proposed that unifies the representation and manipulation of adaptive rule-driven devices and states a common framework for representing and manipulating them. The main feature of this formulation is that it fully preserves the nature of the underlying non-adaptive formalism, so that the adaptive resulting device be easily understood by people familiar to the subjacent device. For illustration purposes, a two-fold case-study is presented, describing adaptive decision tables as adaptive rule-driven devices, and using them for emulating the behavior of a very simple adaptive automaton, which is in turn another adaptive rule-driven device.
The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
Workshop on Implementing Automata/Conference on Implementation and Application of Automata, 2001
A formal device is said to be adaptive whenever its behavior changes dynamically, in a direct res... more A formal device is said to be adaptive whenever its behavior changes dynamically, in a direct response to its input stimuli, without interference of external agents, even its users. In order to achieve this feature, adaptive devices have to be self-modifiable. In other words, any possible changes in the device’s behavior must be known at their full extent at any step of its operation in which the changes have to take place. Therefore, adaptive devices must be able to detect all situations causing possible modifications and to adequately react by imposing corresponding changes to the device’s behavior. In this work, devices are considered whose behavior is based on the operation of subjacent non-adaptive devices that be fully described by some finite set of rules. An adaptive rule-driven device may be obtained by attaching adaptive actions to the rules of the subjacent formulation, so that whenever a rule is applied, the associated adaptive action is activated, causing the set of rules of the subjacent non-adaptive device to be correspondingly changed. In this paper a new general formulation is proposed that unifies the representation and manipulation of adaptive rule-driven devices and states a common framework for representing and manipulating them. The main feature of this formulation is that it fully preserves the nature of the underlying non-adaptive formalism, so that the adaptive resulting device be easily understood by people familiar to the subjacent device. For illustration purposes, a two-fold case-study is presented, describing adaptive decision tables as adaptive rule-driven devices, and using them for emulating the behavior of a very simple adaptive automaton, which is in turn another adaptive rule-driven device.
Workshop on Implementing Automata/Conference on Implementation and Application of Automata, 2001
A formal device is said to be adaptive whenever its behavior changes dynamically, in a direct res... more A formal device is said to be adaptive whenever its behavior changes dynamically, in a direct response to its input stimuli, without interference of external agents, even its users. In order to achieve this feature, adaptive devices have to be self-modifiable. In other words, any possible changes in the device’s behavior must be known at their full extent at any step of its operation in which the changes have to take place. Therefore, adaptive devices must be able to detect all situations causing possible modifications and to adequately react by imposing corresponding changes to the device’s behavior. In this work, devices are considered whose behavior is based on the operation of subjacent non-adaptive devices that be fully described by some finite set of rules. An adaptive rule-driven device may be obtained by attaching adaptive actions to the rules of the subjacent formulation, so that whenever a rule is applied, the associated adaptive action is activated, causing the set of rules of the subjacent non-adaptive device to be correspondingly changed. In this paper a new general formulation is proposed that unifies the representation and manipulation of adaptive rule-driven devices and states a common framework for representing and manipulating them. The main feature of this formulation is that it fully preserves the nature of the underlying non-adaptive formalism, so that the adaptive resulting device be easily understood by people familiar to the subjacent device. For illustration purposes, a two-fold case-study is presented, describing adaptive decision tables as adaptive rule-driven devices, and using them for emulating the behavior of a very simple adaptive automaton, which is in turn another adaptive rule-driven device.
The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
Workshop on Implementing Automata/Conference on Implementation and Application of Automata, 2001
A formal device is said to be adaptive whenever its behavior changes dynamically, in a direct res... more A formal device is said to be adaptive whenever its behavior changes dynamically, in a direct response to its input stimuli, without interference of external agents, even its users. In order to achieve this feature, adaptive devices have to be self-modifiable. In other words, any possible changes in the device’s behavior must be known at their full extent at any step of its operation in which the changes have to take place. Therefore, adaptive devices must be able to detect all situations causing possible modifications and to adequately react by imposing corresponding changes to the device’s behavior. In this work, devices are considered whose behavior is based on the operation of subjacent non-adaptive devices that be fully described by some finite set of rules. An adaptive rule-driven device may be obtained by attaching adaptive actions to the rules of the subjacent formulation, so that whenever a rule is applied, the associated adaptive action is activated, causing the set of rules of the subjacent non-adaptive device to be correspondingly changed. In this paper a new general formulation is proposed that unifies the representation and manipulation of adaptive rule-driven devices and states a common framework for representing and manipulating them. The main feature of this formulation is that it fully preserves the nature of the underlying non-adaptive formalism, so that the adaptive resulting device be easily understood by people familiar to the subjacent device. For illustration purposes, a two-fold case-study is presented, describing adaptive decision tables as adaptive rule-driven devices, and using them for emulating the behavior of a very simple adaptive automaton, which is in turn another adaptive rule-driven device.
The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
Workshop on Implementing Automata/Conference on Implementation and Application of Automata, 2001
A formal device is said to be adaptive whenever its behavior changes dynamically, in a direct res... more A formal device is said to be adaptive whenever its behavior changes dynamically, in a direct response to its input stimuli, without interference of external agents, even its users. In order to achieve this feature, adaptive devices have to be self-modifiable. In other words, any possible changes in the device’s behavior must be known at their full extent at any step of its operation in which the changes have to take place. Therefore, adaptive devices must be able to detect all situations causing possible modifications and to adequately react by imposing corresponding changes to the device’s behavior. In this work, devices are considered whose behavior is based on the operation of subjacent non-adaptive devices that be fully described by some finite set of rules. An adaptive rule-driven device may be obtained by attaching adaptive actions to the rules of the subjacent formulation, so that whenever a rule is applied, the associated adaptive action is activated, causing the set of rules of the subjacent non-adaptive device to be correspondingly changed. In this paper a new general formulation is proposed that unifies the representation and manipulation of adaptive rule-driven devices and states a common framework for representing and manipulating them. The main feature of this formulation is that it fully preserves the nature of the underlying non-adaptive formalism, so that the adaptive resulting device be easily understood by people familiar to the subjacent device. For illustration purposes, a two-fold case-study is presented, describing adaptive decision tables as adaptive rule-driven devices, and using them for emulating the behavior of a very simple adaptive automaton, which is in turn another adaptive rule-driven device.
Workshop on Implementing Automata/Conference on Implementation and Application of Automata, 2001
A formal device is said to be adaptive whenever its behavior changes dynamically, in a direct res... more A formal device is said to be adaptive whenever its behavior changes dynamically, in a direct response to its input stimuli, without interference of external agents, even its users. In order to achieve this feature, adaptive devices have to be self-modifiable. In other words, any possible changes in the device’s behavior must be known at their full extent at any step of its operation in which the changes have to take place. Therefore, adaptive devices must be able to detect all situations causing possible modifications and to adequately react by imposing corresponding changes to the device’s behavior. In this work, devices are considered whose behavior is based on the operation of subjacent non-adaptive devices that be fully described by some finite set of rules. An adaptive rule-driven device may be obtained by attaching adaptive actions to the rules of the subjacent formulation, so that whenever a rule is applied, the associated adaptive action is activated, causing the set of rules of the subjacent non-adaptive device to be correspondingly changed. In this paper a new general formulation is proposed that unifies the representation and manipulation of adaptive rule-driven devices and states a common framework for representing and manipulating them. The main feature of this formulation is that it fully preserves the nature of the underlying non-adaptive formalism, so that the adaptive resulting device be easily understood by people familiar to the subjacent device. For illustration purposes, a two-fold case-study is presented, describing adaptive decision tables as adaptive rule-driven devices, and using them for emulating the behavior of a very simple adaptive automaton, which is in turn another adaptive rule-driven device.
The present paper introduces the concept of adaptive automata as an alternative formal tool for d... more The present paper introduces the concept of adaptive automata as an alternative formal tool for describing context-dependent languages. This formal framework has the advantage of allowing easy mapping of a language description into an efficient parser for that language. Such a good performance is due to the potential hierarchical structure adaptive automata may exhibit, allowing natural construction of acceptors no more complex than strictly needed by each particular language. Efficiency is also due to the way adaptive automata operate, by changing according to its input, including and discarding transitions as needed to parse the particular input text -adaptive automata start from an initial self-modifying version, and evolve through a path of intermediate configurations until a final configuration is reached, when the source text is exhausted. The evolution from an automaton's configuration to the next one may be designed to occur strictly when a construct is found which is not recognized by the current configuration of the automaton. So, one may view the acceptance of a particular sentence as a sequence of recognitions of its substrings, each operated by the corresponding configuration of the adaptive automaton. That offers a practical way for efficiently accepting context-dependent languages in a purely syntactical way, allowing full treatment for syntactical aspects of the language such as dynamic syntax and the socalled static semantics. Then, the use of adaptive automata brings the possibility of handling in a purelly syntactical way several autentically syntactical concepts, such as predefined words, symbol-tables, scoping, type-checking, argument-to-parameter matching, macro definitions and expansions, syntax macros for defining new language constructs, and many others, usually treated semantically, or resolved outside the parser.
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Papers by João Neto