6e7b8bdf6aeb604219a24f35cf1d303a0cb6edef
kent
  Wed Aug 7 18:08:33 2019 -0700
Librarifying strex string expression module that is going in for tabToTabDir to help sort through some of HCA madness.

diff --git src/lib/strex.doc src/lib/strex.doc
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index 0000000..cb69300
--- /dev/null
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+The strex language is a small string expression evaluation language.  
+This document describes its built in functions:
+
+between(prefix, string, suffix) - returns the part of string found between prefix and suffix
+   example:   between("abc", "01234abcHelloxyz56789", "xyz")  fetches just "Hello"
+   If there are multiple places the prefix occurs, it will choose the first one, and the
+   then the first place the suffix matches after that.  The biologist might think of it as
+   a text oriented PCR, though the primer prefix and suffixes are not included in the output.
+
+split(string, splitter, index) - separates string with splitter character. Returns 0 based index.
+
+spaced(string, index)  - treats string as space separated, and returns word of given 0 based index
+
+trim(string) - returns copy of string with leading and trailing spaces removed
+
+md5(string) - returns an MD5 sum digest/hash of string. Useful for creating IDs
+
+now() - returns current time and date in a really aweful unix ctime(2) format.  We will improve it.
+