1doctools::tcl::parse(n) Documentation tools doctools::tcl::parse(n)
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8 doctools::tcl::parse - Processing text in 'subst -novariables' format
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11 package require Tcl 8.4
12 package require snit
14 package require fileutil
16 package require logger
18 package require struct::list
20 package require struct::stack
22 package require struct::set
24 package require treeql
26 package require doctools::tcl::parse
28 ::doctools::tcl::parse text tree text ?root?
30 ::doctools::tcl::parse file tree path ?root?
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36 This package provides commands for parsing text with embedded Tcl com‐
37 mands as accepted by the Tcl builtin command subst -novariables. The
38 result of the parsing is an abstract syntax tree.
39 This is an internal package of doctools, for use by the higher level
41 parsers processing the docidx, doctoc, and doctools markup languages.
42
44 ::doctools::tcl::parse text tree text ?root?
45 The command takes the text and parses it under the assumption
46 that it contains a string acceptable to the Tcl builtin command
47 subst -novariables. Errors are thrown otherwise during the pars‐
48 ing. The format used for these errors in described in section
49 Error format.
50 The command returns the empty string as it result. The actual
52 result of the parsing is entered into the tree structure tree,
53 under the node root. If root is not specified the root of tree
54 is used. The tree has to exist and be the command of a tree ob‐
55 ject which supports the same methods as trees created by the
56 package struct::tree.
57 In case of errors tree will be left in an undefined state.
59 ::doctools::tcl::parse file tree path ?root?
61 The same as text, except that the text to parse is read from the
62 file specified by path.
63
65 When the parser encounters a problem in the input it will throw an er‐
66 ror using the format described here.
67 [1] The message will contain the reason for the problem (unexpected
69 character or end of input in input), the character in question,
70 if any, and the line and column the problem was found at, in a
71 human readable form. This part is not documented further as its
72 format may change as we see fit. It is intended for human con‐
73 sumption, not machine.
74 [2] The error code however will contain a machine-readable represen‐
76 tation of the problem, in the form of a 5-element list contain‐
77 ing, in the order listed below
78 [1] the constant string doctools::tcl::parse
80 [2] the cause of the problem, one of
82 char Unexpected character in input
84 eof Unexpected end of the input
86 [3] The location of the problem as offset from the beginning
88 of the input, counted in characters. Note: Line markers
89 count as one character.
90 [4] The line the problem was found on (counted from 1 (one)),
92 [5] The column the problem was found at (counted from 0
94 (zero))
95
97 After successfully parsing a string the generated tree will have the
98 following structure:
99 [1] In the following items the word 'root' refers to the node which
101 was specified as the root of the tree when invoking either text
102 or file. This may be the actual root of the tree.
103 [2] All the following items further ignore the possibility of pre-
105 existing attributes in the pre-existing nodes. If attributes ex‐
106 ists with the same names as the attributes used by the parser
107 the pre-existing values are written over. Attributes with names
108 not clashing with the parser's attributes are not touched.
109 [3] The root node has no attributes.
111 [4] All other nodes have the attributes
113 type The value is a string from the set { Command , Text ,
115 Word }
116 range The value is either empty or a 2-element list containing
118 integer numbers. The numbers are the offsets of the first
119 and last character in the input text, of the token de‐
120 scribed by the node,.
121 line The value is an integer, it describes the line in the in‐
123 put the token described by the node ends on. Lines are
124 counted from 1 (one).
125 col The value is an integer, it describes the column in the
127 line in the input the token described by the node ends
128 on. Columns are counted from 0 (zero).
129 [5] The children of the root, if any, are of type Command and Text,
131 in semi-alternation. This means: After a Text node a Command
132 node has to follow, and anything can follow a Command node, a
133 Text or other Command node.
134 [6] The children of a Command node, if any, are of type Command, and
136 Text, and Word, they describe the arguments of the command.
137 [7] The children of a Word node, if any, are of type Command, Text,
139 in semi-alternation. This means: After a Text node a Command
140 node has to follow, and anything can follow a Command node, a
141 Text or other Command node.
142 [8] A Word node without children represents the empty string.
144 [9] All Text nodes are leaves of the tree.
146 [10] All leaves of the tree are either Text or Command nodes. Word
148 nodes cannot be leaves.
149
151 This document, and the package it describes, will undoubtedly contain
152 bugs and other problems. Please report such in the category doctools
153 of the Tcllib Trackers [http://core.tcl.tk/tcllib/reportlist]. Please
154 also report any ideas for enhancements you may have for either package
155 and/or documentation.
156 When proposing code changes, please provide unified diffs, i.e the out‐
158 put of diff -u.
159 Note further that attachments are strongly preferred over inlined
161 patches. Attachments can be made by going to the Edit form of the
162 ticket immediately after its creation, and then using the left-most
163 button in the secondary navigation bar.
164
166 Tcl syntax, command, doctools, parser, subst, word
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169 Documentation tools
170
172 Copyright (c) 2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>
173tcllib 1 doctools::tcl::parse(n)