AnaGram interim repo (temporary): doc/manual/pcb.tex annotate

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author	David A. Holland
date	Mon, 13 Jun 2022 00:40:23 -0400
parents	13d2b8934445
children

rev	line source
0 13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	1 \chapter{Parser Control Block}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	2
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	3 \index{PCB}\index{Parser control block}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	4 A \agterm{parser control block} is a structure which contains all of
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	5 the data necessary to describe the instantaneous state of a parser.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	6 The \agcode{typedef} statement which defines the structure is included
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	7 in the \index{Header file}\index{File}header file for your parser.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	8 AnaGram creates the name of the \index{Name}data type for the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	9 structure by appending \agcode{{\us}pcb{\us}type} to the parser name.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	10
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	11 % XXX: does \index{Name} belong?
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	12 If the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	13 \index{Declare pcb}\index{Configuration switches}\agparam{declare pcb}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	14 configuration switch is on, its default state, AnaGram will declare a
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	15 parser control block for you at the beginning of your parser file.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	16 AnaGram will determine the \index{Name}name of the parser control
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	17 block by appending \agcode{{\us}pcb} to the parser name. AnaGram will
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	18 also define the macro \index{PCB}\index{Macros}\agcode{PCB} as a
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	19 shorthand notation for use within the parser.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	20
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	21 If you wish to declare your own parser control block, you must include
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	22 the header file for your parser before your declaration. Then you
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	23 declare a parser control block and define \agcode{PCB} to refer to the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	24 control block you have declared.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	25
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	26 Suppose your grammar is called \agcode{widget}. You would then write
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	27 the following statements in your embedded C in order to declare a
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	28 parser control block named \agcode{widget{\us}control}:
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	29
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	30 \begin{indentingcode}{0.4in}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	31 \#include "widget.h"
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	32 widget{\us}pcb{\us}type widget{\us}control;
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	33 \#define PCB widget{\us}control
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	34 \end{indentingcode}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	35
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	36 The remainder of this appendix describes fields in the parser control
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	37 block that may interest the user:
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	38
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	39 \index{column}\index{PCB}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	40 \paragraph{\agcode{int column;}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	41 \agcode{PCB.column} keeps track of the column number of the current
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	42 character in your input. Line and column numbers are tracked only if
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	43 the \index{Lines and columns}\index{Configuration switches}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	44 \agparam{lines and columns} configuration switch has been set.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	45
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	46 \index{cs}\index{PCB}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	47 \paragraph{\agcode{\textit{context-type} cs[];}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	48 \agcode{PCB.cs} is your \index{Context stack}\index{Stack}context
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	49 stack. \agcode{cs} will be defined only if you have assigned a value
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	50 to the configuration parameter
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	51 \index{Context type}\index{Configuration parameters}\agparam{context type}.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	52
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	53 \index{error{\us}frame{\us}ssx}\index{PCB}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	54 \paragraph{\agcode{int error{\us}frame{\us}ssx;}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	55 \agcode{PCB.error{\us}frame{\us}ssx} is a field to which your error handling
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	56 routines may refer. When your
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	57 \index{SYNTAX{\us}ERROR}\index{Macros}\agcode{SYNTAX{\us}ERROR} macro is
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	58 called, if you have set both the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	59 \index{Diagnose errors}\index{Configuration switches}\agparam{diagnose errors}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	60 and
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	61 \index{Error frame}\index{Configuration switches}\agparam{error frame}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	62 configuration switches,
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	63 \agcode{PCB.error{\us}frame{\us}ssx} will contain the value of the parser
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	64 stack index at the beginning of the frame token identified by
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	65 \agcode{PCB.error{\us}frame{\us}token}. For example, if in a syntax file,
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	66 you fail to close a comment, AnaGram will encounter an illegal end of
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	67 file in the comment. In this situation, \agcode{error{\us}frame{\us}token} is
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	68 the comment token, and \agcode{PCB.error{\us}frame{\us}ssx} gives the parser
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	69 stack depth at the beginning of the comment.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	70
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	71 \index{error{\us}frame{\us}token}\index{PCB}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	72 \paragraph{\agcode{int error{\us}frame{\us}token;}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	73 \agcode{PCB.error{\us}frame{\us}token} is a field to which
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	74 your error handling routines may refer. When your
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	75 \index{SYNTAX{\us}ERROR}\index{Macros}\agcode{SYNTAX{\us}ERROR} macro is
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	76 called, if you have set both
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	77 \index{Diagnose errors}\index{Configuration switches}\agparam{diagnose errors}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	78 and
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	79 \index{Error frame}\index{Configuration switches}\agparam{error frame},
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	80 it will contain the token number of the frame token, a token which
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	81 identifies the context of the error.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	82
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	83 \index{error{\us}message}\index{PCB}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	84 \paragraph{\agcode{char *error{\us}message;}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	85 \agcode{PCB.error{\us}message} is a field to which your error handling
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	86 procedures may refer. If you have set the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	87 \index{Diagnose errors}\index{Configuration switches}\agparam{diagnose errors}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	88 configuration switch, on encountering a syntax error your parser will
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	89 create a string containing an appropriate diagnostic message and store
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	90 a pointer to it into \agcode{PCB.error{\us}message}.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	91
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	92 \index{PCB}\index{exit{\us}flag}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	93 \paragraph{\agcode{int exit{\us}flag;}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	94 \agcode{PCB.exit{\us}flag} contains a code value which indicates
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	95 whether the parser is still running or whether it has terminated. If
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	96 the parser has terminated, \agcode{PCB.exit{\us}flag} indicates the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	97 reason the parse has terminated. Mnemonic values for these \index{Exit
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	98 codes}exit codes are defined in the header file for your parser. The
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	99 values are as follows:
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	100 % XXX s/mnemonic/symbolic/
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	101
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	102 \begin{tabular}{ll}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	103 \agcode{AG{\us}RUNNING{\us}CODE} & 0\\
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	104 \agcode{AG{\us}SUCCESS{\us}CODE} & 1\\
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	105 \agcode{AG{\us}SYNTAX{\us}ERROR{\us}CODE} & 2\\
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	106 \agcode{AG{\us}REDUCTION{\us}ERROR{\us}CODE} & 3\\
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	107 \agcode{AG{\us}STACK{\us}ERROR{\us}CODE} & 4\\
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	108 \agcode{AG{\us}SEMANTIC{\us}ERROR{\us}CODE} & 5
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	109 \end{tabular}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	110
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	111 \index{PCB}\index{input{\us}code}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	112 \paragraph{\agcode{int input{\us}code;}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	113 \agcode{PCB.input{\us}code} contains the current input character, or
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	114 the token number, if your
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	115 \index{GET{\us}INPUT}\index{Macros}\agcode{GET{\us}INPUT} macro supplies
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	116 token numbers directly.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	117
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	118 If you write your own \agcode{GET{\us}INPUT} macro, you must make sure
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	119 that you store the input character or token number you get into
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	120 \agcode{PCB.input{\us}code}.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	121
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	122 If you have configured your parser to be
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	123 \index{Event driven}\index{Configuration switches}\agparam{event driven},
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	124 you must store the input character or token number for each token in
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	125 turn into \agcode{PCB.input{\us}code} before you call your parser to
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	126 process it.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	127
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	128 \index{PCB}\index{input{\us}context}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	129 \paragraph{\agcode{\textit{context-type} input{\us}context;}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	130 \agcode{PCB.input{\us}context} is a field which AnaGram adds to the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	131 definition of the parser control block structure when you assign a
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	132 value to the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	133 \index{Context type}\index{Configuration parameters}\agparam{context type}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	134 configuration parameter. If you choose, you can
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	135 write your \index{GET{\us}INPUT}\index{Macros}\agcode{GET{\us}INPUT} macro
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	136 so that it stores the context value in \agcode{PCB.input{\us}context}.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	137 The default definition for
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	138 \index{GET{\us}CONTEXT}\index{Macros}\agcode{GET{\us}CONTEXT} will
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	139 then stack the context value at the appropriate time. You can think
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	140 of \agcode{PCB.input{\us}context} as a sort of temporary ``parking
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	141 place'' for the context value.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	142
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	143 \index{PCB}\index{input{\us}value}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	144 \paragraph{\agcode{\textit{input-value-type} input{\us}value;}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	145 \agcode{PCB.input{\us}value} is a field in the parser control block which
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	146 is used to store the value of the input token.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	147
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	148 If you write your own
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	149 \index{Macros}\index{GET{\us}INPUT}\agcode{GET{\us}INPUT} macro or use
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	150 \index{Event driven}\index{Configuration switches}\agparam{event driven}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	151 input, and you have set the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	152 \index{Input values}\index{Configuration switches}\agparam{input values}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	153 configuration switch, you should make sure that you store the value of
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	154 the input character or token into \agcode{PCB.input{\us}value}.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	155
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	156 \index{PCB}\index{line}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	157 \paragraph{\agcode{int line;}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	158 \agcode{PCB.line} contains the line number of the current character in
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	159 your input. Line and column numbers are tracked only if the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	160 \index{Lines and columns}\index{Configuration switches}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	161 \agparam{lines and columns} configuration switch has been set.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	162
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	163 \index{PCB}\index{pointer}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	164 \paragraph{\agcode{\textit{pointer-type} pointer;}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	165 \agcode{PCB.pointer} will be included in the parser control block for
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	166 your parser if you have set the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	167 \index{Pointer input}\index{Configuration switches}\agparam{pointer input}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	168 configuration switch. The type of \agcode{PCB.pointer} is determined
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	169 by the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	170 \index{Pointer type}\index{Configuration parameters}\agparam{pointer type}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	171 configuration parameter, which defaults to \agcode{unsigned char *}.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	172 Your main program should set \agcode{PCB.pointer} before it calls your
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	173 parser. Thereafter, your parser will increment it appropriately.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	174 When you are executing a reduction procedure or a
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	175 \index{SYNTAX{\us}ERROR}\index{Macros}\agcode{SYNTAX{\us}ERROR} macro
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	176 \agcode{PCB.pointer} will always point to the next input character to
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	177 be read.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	178
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	179 \index{PCB}\index{reduction{\us}token}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	180 \paragraph{\agcode{int reduction{\us}token;}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	181 Whenever your parser executes a reduction procedure,
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	182 \agcode{PCB.reduction{\us}token} contains the number of the token to
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	183 which the rule being reduced is to reduce to. If your grammar uses
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	184 semantically determined productions, your reduction procedure may
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	185 change the value of \agcode{PCB.reduction{\us}token} to the desired
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	186 value.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	187
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	188 Prior to calling your reduction procedure, your parser will set this
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	189 field to the token number of the default reduction token, i.e., the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	190 first token in the reduction token list for the production being
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	191 reduced. If the reduction procedure establishes that a different
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	192 reduction token is appropriate, it should store the appropriate token
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	193 number in \agcode{PCB.reduction{\us}token}. The easiest way to do this
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	194 is to use the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	195 \index{CHANGE{\us}REDUCTION}\index{Macros}\agcode{CHANGE{\us}REDUCTION}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	196 macro.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	197
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	198 \index{PCB}\index{sn}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	199 \paragraph{\agcode{int sn;}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	200 \agcode{PCB.sn} always contains the current
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	201 \index{State}\index{Number}state number of your parser.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	202
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	203 \index{PCB}\index{ss}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	204 \paragraph{\agcode{int ss[];}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	205 \agcode{PCB.ss} is the \index{Parser state stack}\index{State
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	206 stack}\index{Stack}state stack for your parser. Before every shift action,
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	207 the current state number, \agcode{PCB.sn}, is stored in
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	208 \agcode{PCB.ss[PCB.ssx]}. \agcode{PCB.ssx} is then incremented.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	209
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	210 \index{PCB}\index{ssx}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	211 \paragraph{\agcode{int ssx;}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	212 \agcode{PCB.ssx} contains the parser \index{Stack}stack index for your
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	213 parser. On every shift action it is incremented. On every reduction
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	214 action the length of the grammar rule being reduced is subtracted from
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	215 \agcode{PCB.ssx}.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	216
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	217 \index{PCB}\index{token{\us}number}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	218 \paragraph{\agcode{int token{\us}number;}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	219 \agcode{PCB.token{\us}number} contains the internal \index{Token
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	220 number}\index{Number}token number of the current input token. If you
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	221 are not supplying token numbers directly, it is the result of using
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	222 the actual input character to index the token conversion array,
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	223 \agcode{ag{\us}tcv}.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	224
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	225 Your parser automatically maintains the proper value in
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	226 \agcode{PCB.token{\us}number}. Input token numbers should always be
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	227 stored in \agcode{PCB.input{\us}code}.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	228
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	229 % XXX ``is a field is the''?
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	230 \index{vs}\index{PCB}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	231 \paragraph{\agcode{\textit{value-stack-type} vs[];}}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	232 \agcode{PCB.vs} is a field is the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	233 \index{Parser value stack}\index{Stack}\index{Value stack}value stack
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	234 for your parser. The semantic values of the tokens identified by the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	235 parser are stored in the value \index{Stack}\index{Value stack}stack.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	236 The value stack, like the other parser stacks, is indexed by
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	237 \agcode{PCB.ssx}.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	238 When your parser is executing a reduction procedure,
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	239 \agcode{PCB.vs[PCB.ssx]} contains the semantic value of the first
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	240 token in the grammar rule you are reducing, \agcode{PCB.vs[PCB.ssx+1]}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	241 contains the second, and so forth. The return value from your
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	242 reduction procedure will be stored in turn in
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	243 \agcode{PCB.vs[PCB.ssx]}.
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	244
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	245 \index{{\us}dol{\us}vt}
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	246 \agcode{PCB.vs} is defined to be of type \agcode{\${\us}vt}, where
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	247 ``\agcode{\$}'' represents the name of your syntax file. AnaGram
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	248 defines \agcode{\${\us}vt} so that it is large enough to store the
13d2b8934445 Import AnaGram (near-)release tree into Mercurial. David A. Holland parents: diff changeset	249 semantic value of any of the tokens declared in your grammar.

Mercurial > ~dholland > hg > ag > index.cgi

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