| File scan_util.icn |
General purpose scanning routines contributed by various people.
This is one of several files contributing to the util package.
Author: Steve Wampler (sbw@tapestry.tucson.az.us)
This file is in the public domain.
This file is part of the util package.
Source code.| Details |
| Procedures: |
skipped over whitespace, if any |
if no whitespace |
Skip whitespace. This is a matching procedure.
Like find, but accepts a list of strings and finds them by their order of appearance in the subject string. The list of strings is searched in order. To locate the longest substring first, sort the list in reverse order, as in:
findFirst(::reverse(::sort(a)))
Deprecated in favor of the FindFirst class.
List of strings to look for.s | String to examine
|
esc | Escape character (defaults to <tt>\</tt>)
|
s if it ends in an odd number of escape characters |
Succeed if string s ends in an odd number of escape characters. This is a specialty procedure - it's intended to simplify the task of determining if the 'next' character of the string that has s as a substring is escaped or not. If this procedure succeeds, that 'next' character is escaped and s is returned.
The second parameter defaults to a backslash, the traditional escape character.
This is not a scanning procedure, but is placed in this source file to avoid circular dependencies when building.
matched substrings |
Tabmatch a Unicon cset This is a matching procedure.
matched substrings |
Tabmatch a Unicon string This is a matching procedure.
matched Unicon variable name |
Tabmatch past a Unicon variable name. This is a matching procedure.
keyStrings | table of start->stop pairs |
matching substrings |
Match strings the same way bal() matches characters. The input table is a tagged set of strings to match. The key is the start string while the value is the end string. This makes sure the start and stop strings are balanced w.r.t each other.
For example, given the table:
t := table()
t["begin"] := "end"
then the code:
if match("begin") then
clause := sbal(t)
assigns to clause the substring from begin through
the matching end. (Assuming, of course, that there are no
conflicts along the way...)
This is an unoptimized preliminary version that may contain bugs.
prefix | Precedes any output (default is "")
|
n |
an empty string, corresponding to a move(0) |
Similar to snapshot(), but displays only a portion of very long scan subjects. This is a (trivially) matching procedure.
amount of &subject to show (default is 80)n | number of characters to move over in subject string |
Skip over n characters in subject string. This is similar to move(), but doesn't construct a substring.
p | position to jump to in subject string |
Skip to a position in the subject string. This is similar to tab(), but doesn't construct a substring.
an empty string, corresponding to a move(0) |
Produce a 'snapshot' of string scanning showing the current scanning position. This is a (trivially) matching procedure.
Precedes any output (default is "") matched substrings |
Tabmatch past the next unescaped character in cs Fails if no such unescaped character exists. This is a matching procedure.
cset of characters to tab past. tabbed over portion, omitting skipped substring |
Produce everything up to a substring and skip past that substring. This is a matching procedure. On success, the scanning position is left after the substring.
substring to tab up to and skip over skipped over whitespace, if any |
Matches 0 or more whitespace characters (Cannot fail) This is a matching procedure.