add PIRegularExpression

3rd/pcre2/doc/pcre2_set_optimize.3

@@ -0,0 +1,42 @@
+.TH PCRE2_SET_OPTIMIZE 3 "22 September 2024" "PCRE2 10.45"
+.SH NAME
+PCRE2 - Perl-compatible regular expressions (revised API)
+.SH SYNOPSIS
+.rs
+.sp
+.B #include <pcre2.h>
+.PP
+.nf
+.B int pcre2_set_optimize(pcre2_compile_context *\fIccontext\fP,
+.B "  uint32_t \fIdirective\fP);"
+.fi
+.
+.SH DESCRIPTION
+.rs
+.sp
+This function controls which performance optimizations will be applied
+by \fBpcre2_compile()\fP. It can be called multiple times with the same compile
+context; the effects are cumulative, with the effects of later calls taking
+precedence over earlier ones.
+.P
+The result is zero for success, PCRE2_ERROR_NULL if \fIccontext\fP is NULL,
+or PCRE2_ERROR_BADOPTION if \fIdirective\fP is unknown. The latter could be
+useful to detect if a certain optimization is available.
+.P
+The list of possible values for the \fIdirective\fP parameter are:
+.sp
+  PCRE2_OPTIMIZATION_FULL   Enable all optimizations (default)
+  PCRE2_OPTIMIZATION_NONE   Disable all optimizations
+  PCRE2_AUTO_POSSESS        Enable auto-possessification
+  PCRE2_AUTO_POSSESS_OFF    Disable auto-possessification
+  PCRE2_DOTSTAR_ANCHOR      Enable implicit dotstar anchoring
+  PCRE2_DOTSTAR_ANCHOR_OFF  Disable implicit dotstar anchoring
+  PCRE2_START_OPTIMIZE      Enable start-up optimizations at match time
+  PCRE2_START_OPTIMIZE_OFF  Disable start-up optimizations at match time
+.sp
+There is a complete description of the PCRE2 native API, including detailed
+descriptions \fIdirective\fP parameter values in the
+.\" HREF
+\fBpcre2api\fP
+.\"
+page.