'\"
'\" Copyright (c) 2025 Ashok P. Nadkarni
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
.TH Tcl_UtfToNormalized 3 "9.1" Tcl "Tcl Library Procedures"
.so man.macros
.BS
.SH NAME
Tcl_UtfToNormalized, Tcl_UtfToNormalizedDString \- procedures for Unicode normalization
.SH SYNOPSIS
.nf
\fB#include <tcl.h>\fR
.sp
int
\fBTcl_UtfToNormalized\fR(\fIinterp, src, numBytes, normForm, profile, dst, dstLen, dstWrotePtr\fR)
.sp
int
\fBTcl_UtfToNormalizedDString\fR(\fIinterp, src, numBytes, normForm, profile, dstPtr\fR)
.fi
.SH ARGUMENTS
.AP Tcl_Interp *interp in
Interpreter to use for error reporting, or NULL if no error reporting is
desired.
.AP "const char" *src in
An array of bytes in Tcl's internal UTF-8 based encoding.
.AP Tcl_Size numBytes in
Length of \fIsrc\fR in bytes.  If the length is negative,
the length includes all bytes until the first nul byte.
.AP char *dst out
Buffer in which the converted result will be stored.  No more than
\fIdstLen\fR bytes will be stored in \fIdst\fR.
.AP Tcl_Size dstLen in
The size of the output buffer \fIdst\fR in bytes.
.AP Tcl_Size *dstWrotePtr out
Filled with the number of bytes in the normalized string. This number
does not include the terminating nul character.
May be NULL.
.AP Tcl_UnicodeNormalizationForm normForm in
Must be one of the \fBTcl_UnicodeNormalizationForm\fR members
\fBTCL_NFC\fR, \fBTCL_NFD\fR, \fBTCL_NFKC\fR or \fBTCL_NFKD\fR specifying
the Unicode normalization type.
.AP int profile in/out
The encoding profile as described in the \fBTcl_GetEncoding\fR documentation.
Must be either \fBTCL_ENCODING_PROFILE_STRICT\fR
or \fBTCL_ENCODING_PROFILE_REPLACE\fR.
.AP Tcl_DString *dstPtr out
Pointer to an uninitialized or free \fBTcl_DString\fR in which the converted
result, which is also encoded in Tcl's internal UTF-8 encoding, will be stored.
The function initializes the storage and caller must call
\fBTcl_DStringFree\fR on success.
.BE
.SH DESCRIPTION
.PP
The \fBTcl_UtfToNormalized\fR and \fBTcl_UtfToNormalizedDString\fR functions
transform the passed string into one of the standard normalization forms defined
in the Unicode standard. The normalization form is specified via the
\fInormForm\fR argument which must have one of the values \fBTCL_NFC\fR,
\fBTCL_NFD\fR, \fBTCL_NFKC\fR or \fBTCL_NFKD\fR corresponding to the Unicode
normalization forms \fBNormalization Form C\fR (NFC), \fBNormalization Form D\fR
(NFD), \fBNormalization Form KC\fR (NFKC) and \fBNormalization Form KD\fR (NFKD)
respectively. For details on the above normalization forms, refer to Section
3.11 of the Unicode standard
(https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-3/).
.PP
The \fBTcl_UtfToNormalized\fR function stores the normalized result
in the buffer provided by the caller through the \fIdst\fR argument. The
result is nul terminated but the nul is not included in the count of
stored bytes returned in \fIdstWrotePtr\fR. The function returns TCL_OK
on success, TCL_CONVERT_NOSPACE if there is insufficient room in the output
buffer and TCL_ERROR in case of other failures. In the latter two cases,
an error message is stored in \fIinterp\fR if it is not NULL.
.PP
The \fBTcl_UtfToNormalizedDString\fR function stores the normalized result
in \fIdstPtr\fR which must eventually be freed by caller through
\fBTcl_DStringFree\fR. The function returns TCL_OK on success and
TCL_ERROR on failure with an error message in \fIinterp\fR if it is not NULL.
.SH "SEE ALSO"
unicode(n)
.SH KEYWORDS
utf, Unicode, normalize