'\" '\" Generated from file 'dexec\&.man' by tcllib/doctools with format 'nroff' '\" Copyright (c) 2004 Andreas Kupries '\" Copyright (c) 2007 Bogdan '\" .TH "grammar::fa::dexec" 3tcl 0\&.2 tcllib "Finite automaton operations and usage" .\" The -*- nroff -*- definitions below are for supplemental macros used .\" in Tcl/Tk manual entries. .\" .\" .AP type name in/out ?indent? .\" Start paragraph describing an argument to a library procedure. .\" type is type of argument (int, etc.), in/out is either "in", "out", .\" or "in/out" to describe whether procedure reads or modifies arg, .\" and indent is equivalent to second arg of .IP (shouldn't ever be .\" needed; use .AS below instead) .\" .\" .AS ?type? ?name? .\" Give maximum sizes of arguments for setting tab stops. Type and .\" name are examples of largest possible arguments that will be passed .\" to .AP later. If args are omitted, default tab stops are used. .\" .\" .BS .\" Start box enclosure. From here until next .BE, everything will be .\" enclosed in one large box. .\" .\" .BE .\" End of box enclosure. .\" .\" .CS .\" Begin code excerpt. .\" .\" .CE .\" End code excerpt. .\" .\" .VS ?version? ?br? .\" Begin vertical sidebar, for use in marking newly-changed parts .\" of man pages. The first argument is ignored and used for recording .\" the version when the .VS was added, so that the sidebars can be .\" found and removed when they reach a certain age. If another argument .\" is present, then a line break is forced before starting the sidebar. .\" .\" .VE .\" End of vertical sidebar. .\" .\" .DS .\" Begin an indented unfilled display. .\" .\" .DE .\" End of indented unfilled display. .\" .\" .SO ?manpage? .\" Start of list of standard options for a Tk widget. The manpage .\" argument defines where to look up the standard options; if .\" omitted, defaults to "options". The options follow on successive .\" lines, in three columns separated by tabs. .\" .\" .SE .\" End of list of standard options for a Tk widget. .\" .\" .OP cmdName dbName dbClass .\" Start of description of a specific option. cmdName gives the .\" option's name as specified in the class command, dbName gives .\" the option's name in the option database, and dbClass gives .\" the option's class in the option database. .\" .\" .UL arg1 arg2 .\" Print arg1 underlined, then print arg2 normally. .\" .\" .QW arg1 ?arg2? .\" Print arg1 in quotes, then arg2 normally (for trailing punctuation). .\" .\" .PQ arg1 ?arg2? .\" Print an open parenthesis, arg1 in quotes, then arg2 normally .\" (for trailing punctuation) and then a closing parenthesis. .\" .\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages. .if t .wh -1.3i ^B .nr ^l \n(.l .ad b .\" # Start an argument description .de AP .ie !"\\$4"" .TP \\$4 .el \{\ . ie !"\\$2"" .TP \\n()Cu . el .TP 15 .\} .ta \\n()Au \\n()Bu .ie !"\\$3"" \{\ \&\\$1 \\fI\\$2\\fP (\\$3) .\".b .\} .el \{\ .br .ie !"\\$2"" \{\ \&\\$1 \\fI\\$2\\fP .\} .el \{\ \&\\fI\\$1\\fP .\} .\} .. .\" # define tabbing values for .AP .de AS .nr )A 10n .if !"\\$1"" .nr )A \\w'\\$1'u+3n .nr )B \\n()Au+15n .\" .if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n .nr )C \\n()Bu+\\w'(in/out)'u+2n .. .AS Tcl_Interp Tcl_CreateInterp in/out .\" # BS - start boxed text .\" # ^y = starting y location .\" # ^b = 1 .de BS .br .mk ^y .nr ^b 1u .if n .nf .if n .ti 0 .if n \l'\\n(.lu\(ul' .if n .fi .. .\" # BE - end boxed text (draw box now) .de BE .nf .ti 0 .mk ^t .ie n \l'\\n(^lu\(ul' .el \{\ .\" Draw four-sided box normally, but don't draw top of .\" box if the box started on an earlier page. .ie !\\n(^b-1 \{\ \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' .\} .el \}\ \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' .\} .\} .fi .br .nr ^b 0 .. .\" # VS - start vertical sidebar .\" # ^Y = starting y location .\" # ^v = 1 (for troff; for nroff this doesn't matter) .de VS .if !"\\$2"" .br .mk ^Y .ie n 'mc \s12\(br\s0 .el .nr ^v 1u .. .\" # VE - end of vertical sidebar .de VE .ie n 'mc .el \{\ .ev 2 .nf .ti 0 .mk ^t \h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n' .sp -1 .fi .ev .\} .nr ^v 0 .. .\" # Special macro to handle page bottom: finish off current .\" # box/sidebar if in box/sidebar mode, then invoked standard .\" # page bottom macro. .de ^B .ev 2 'ti 0 'nf .mk ^t .if \\n(^b \{\ .\" Draw three-sided box if this is the box's first page, .\" draw two sides but no top otherwise. .ie !\\n(^b-1 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c .el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c .\} .if \\n(^v \{\ .nr ^x \\n(^tu+1v-\\n(^Yu \kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c .\} .bp 'fi .ev .if \\n(^b \{\ .mk ^y .nr ^b 2 .\} .if \\n(^v \{\ .mk ^Y .\} .. .\" # DS - begin display .de DS .RS .nf .sp .. .\" # DE - end display .de DE .fi .RE .sp .. .\" # SO - start of list of standard options .de SO 'ie '\\$1'' .ds So \\fBoptions\\fR 'el .ds So \\fB\\$1\\fR .SH "STANDARD OPTIONS" .LP .nf .ta 5.5c 11c .ft B .. .\" # SE - end of list of standard options .de SE .fi .ft R .LP See the \\*(So manual entry for details on the standard options. .. .\" # OP - start of full description for a single option .de OP .LP .nf .ta 4c Command-Line Name: \\fB\\$1\\fR Database Name: \\fB\\$2\\fR Database Class: \\fB\\$3\\fR .fi .IP .. .\" # CS - begin code excerpt .de CS .RS .nf .ta .25i .5i .75i 1i .. .\" # CE - end code excerpt .de CE .fi .RE .. .\" # UL - underline word .de UL \\$1\l'|0\(ul'\\$2 .. .\" # QW - apply quotation marks to word .de QW .ie '\\*(lq'"' ``\\$1''\\$2 .\"" fix emacs highlighting .el \\*(lq\\$1\\*(rq\\$2 .. .\" # PQ - apply parens and quotation marks to word .de PQ .ie '\\*(lq'"' (``\\$1''\\$2)\\$3 .\"" fix emacs highlighting .el (\\*(lq\\$1\\*(rq\\$2)\\$3 .. .\" # QR - quoted range .de QR .ie '\\*(lq'"' ``\\$1''\\-``\\$2''\\$3 .\"" fix emacs highlighting .el \\*(lq\\$1\\*(rq\\-\\*(lq\\$2\\*(rq\\$3 .. .\" # MT - "empty" string .de MT .QW "" .. .BS .SH NAME grammar::fa::dexec \- Execute deterministic finite automatons .SH SYNOPSIS package require \fBTcl 8\&.4\fR .sp package require \fBsnit \fR .sp package require \fBgrammar::fa::dexec ?0\&.2?\fR .sp \fB::grammar::fa::dexec\fR \fIdaName\fR \fIfa\fR ?\fB-any\fR \fIany\fR? ?\fB-command\fR \fIcmdprefix\fR? .sp \fBdaName\fR \fIoption\fR ?\fIarg arg \&.\&.\&.\fR? .sp \fIdaName\fR \fBdestroy\fR .sp \fIdaName\fR \fBput\fR \fIsymbol\fR .sp \fIdaName\fR \fBreset\fR .sp \fIdaName\fR \fBstate\fR .sp \fIcmdprefix\fR \fBerror\fR \fIcode\fR \fImessage\fR .sp \fIcmdprefix\fR \fBfinal\fR \fIstateid\fR .sp \fIcmdprefix\fR \fBreset\fR .sp \fIcmdprefix\fR \fBstate\fR \fIstateid\fR .sp .BE .SH DESCRIPTION .PP This package provides a class for executors constructed from deterministic \fIfinite automatons\fR (DFA)\&. Executors are objects which are given a string of symbols in a piecemal fashion, perform state transitions and report back when they enter a final state, or find an error in the input\&. For the actual creation of the DFAs the executors are based on we have the packages \fBgrammar::fa\fR and \fBgrammar::fa::op\fR\&. .PP The objects follow a push model\&. Symbols are pushed into the executor, and when something important happens, i\&.e\&. error occurs, a state transition, or a final state is entered this will be reported via the callback specified via the option \fB-command\fR\&. Note that conversion of this into a pull model where the environment retrieves messages from the object and the object uses a callback to ask for more symbols is a trivial thing\&. .PP \fISide note\fR: The acceptor objects provided by \fBgrammar::fa::dacceptor\fR could have been implemented on top of the executors provided here, but were not, to get a bit more performance (we avoid a number of method calls and the time required for their dispatch)\&. .PP .SH API The package exports the API described here\&. .TP \fB::grammar::fa::dexec\fR \fIdaName\fR \fIfa\fR ?\fB-any\fR \fIany\fR? ?\fB-command\fR \fIcmdprefix\fR? Creates a new deterministic executor with an associated global Tcl command whose name is \fIdaName\fR\&. This command may be used to invoke various operations on the executor\&. It has the following general form: .RS .TP \fBdaName\fR \fIoption\fR ?\fIarg arg \&.\&.\&.\fR? \fIOption\fR and the \fIarg\fRs determine the exact behavior of the command\&. See section \fBEXECUTOR METHODS\fR for more explanations\&. .sp The executor will be based on the deterministic finite automaton stored in the object \fIfa\fR\&. It will keep a copy of the relevant data of the FA in its own storage, in a form easy to use for its purposes\&. This also means that changes made to the \fIfa\fR after the construction of the executor \fIwill not\fR influence the executor\&. .sp If \fIany\fR has been specified, then the executor will convert all symbols in the input which are unknown to the base FA to that symbol before proceeding with the processing\&. .RE .PP .SH "EXECUTOR METHODS" .PP All executors provide the following methods for their manipulation: .TP \fIdaName\fR \fBdestroy\fR Destroys the automaton, including its storage space and associated command\&. .TP \fIdaName\fR \fBput\fR \fIsymbol\fR Takes the current state of the executor and the \fIsymbol\fR and performs the appropriate state transition\&. Reports any errors encountered via the command callback, as well as entering a final state of the underlying FA\&. .sp When an error is reported all further invokations of \fBput\fR will do nothing, until the error condition has been cleared via an invokation of method \fBreset\fR\&. .TP \fIdaName\fR \fBreset\fR Unconditionally sets the executor into the start state of the underlying FA\&. This also clears any error condition \fBput\fR may have encountered\&. .TP \fIdaName\fR \fBstate\fR Returns the current state of the underlying FA\&. This allow for introspection without the need to pass data from the callback command\&. .PP .SH "EXECUTOR CALLBACK" The callback command \fIcmdprefix\fR given to an executor via the option \fB-command\fR will be executed by the object at the global level, using the syntax described below\&. Note that \fIcmdprefix\fR is not simply the name of a command, but a full command prefix\&. In other words it may contain additional fixed argument words beyond the command word\&. .TP \fIcmdprefix\fR \fBerror\fR \fIcode\fR \fImessage\fR The executor has encountered an error, and \fImessage\fR contains a human-readable text explaining the nature of the problem\&. The \fIcode\fR on the other hand is a fixed machine-readable text\&. The following error codes can be generated by executor objects\&. .RS .TP \fBBADSYM\fR An unknown symbol was found in the input\&. This can happen if and only if no \fB-any\fR symbol was specified\&. .TP \fBBADTRANS\fR The underlying FA has no transition for the current combination of input symbol and state\&. In other words, the executor was not able to compute a new state for this combination\&. .RE .TP \fIcmdprefix\fR \fBfinal\fR \fIstateid\fR The executor has entered the final state \fIstateid\fR\&. .TP \fIcmdprefix\fR \fBreset\fR The executor was reset\&. .TP \fIcmdprefix\fR \fBstate\fR \fIstateid\fR The FA changed state due to a transition\&. \fIstateid\fR is the new state\&. .PP .PP .SH EXAMPLES .SH "BUGS, IDEAS, FEEDBACK" This document, and the package it describes, will undoubtedly contain bugs and other problems\&. Please report such in the category \fIgrammar_fa\fR of the \fITcllib Trackers\fR [http://core\&.tcl\&.tk/tcllib/reportlist]\&. Please also report any ideas for enhancements you may have for either package and/or documentation\&. .PP When proposing code changes, please provide \fIunified diffs\fR, i\&.e the output of \fBdiff -u\fR\&. .PP Note further that \fIattachments\fR are strongly preferred over inlined patches\&. Attachments can be made by going to the \fBEdit\fR form of the ticket immediately after its creation, and then using the left-most button in the secondary navigation bar\&. .SH KEYWORDS automaton, execution, finite automaton, grammar, parsing, regular expression, regular grammar, regular languages, running, state, transducer .SH CATEGORY Grammars and finite automata .SH COPYRIGHT .nf Copyright (c) 2004 Andreas Kupries Copyright (c) 2007 Bogdan .fi