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

annotate doc/manual/pcb.tex @ 21:1c9dac05d040

Add lint-style FALLTHROUGH annotations to fallthrough cases. (in the parse engine and thus the output code) Document this, because the old output causes warnings with gcc10.

author	David A. Holland
date	Mon, 13 Jun 2022 00:04:38 -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

annotate doc/manual/pcb.tex @ 21:1c9dac05d040