lgrxenc.def

comprehensive LGR Greek font encoding definitions

Copyright: © 2010 Günter Milde
Licence: This work may be distributed and/or modified under the conditions of the LaTeX Project Public License, either version 1.3 of this license or any later version.

Abstract

The LGR font encoding is the de-facto standard for Greek

typesetting with LaTeX. However, the encoding definition file that ships with babel misses many of the definitions common since the advent of the NFSS (see fntguide "Encodings").

This file provides a comprehensive set of macros to typeset Greek with LGR encoded fonts. It works for both, monotonic and polytonic Greek, independent of the babel package.

This package is part of the lgrx bundle.

Contents

Changelog

0.1	2010-03-31	initial attempt
0.2	2010-04-20	diacritics dropped in UPPERCASE
0.3	2010-06-08	handle Titlecase and UPPERCASE extending `\@uclclist`
0.3.1	2010-06-10	code cleanup: replace dummy accent hack with TextCommand
0.4	2010-06-15	more text symbols
0.4.1	2010-08-06	prevent multiple evaluation
0.5	2010-08-27	support `\textalpha` ... `\textOmega`
0.5.1	2012-05-08	upload to CTAN
0.6	2012-06-29	`\TextGreek` wrapper command (used in lgrenc.dfu), aliases for `puenc.def` compatibility

Usage

To prevent confusion with Babel's rudimentary lgrenc.def, this file is named lgrxenc.def. Load it by calling fontenc with the LGRx option or indirectly via the textalpha or alphabeta packages.

Example:: Select font encodings T1 (as default) and LGR (with the comprehensive font encoding definitions)

\usepackage[LGRx,T1]{fontenc}

Attention!

The name of the font encoding defined by the option LGRx is not LGRx but LGR. Therefore, LGRx must not be the last option (as fontenc uses the last option to select the default font encoding). To set LGR as as default font encoding specify both, LGRx and LGR, e.g.

\usepackage[LGRx,T1,LGR]{fontenc}

Macro names

The fntguide (section 6.4 Naming conventions) recommends:

Where possible, text symbols should be named as \text followed by the Adobe glyph name: for example \textonequarter or \textsterling. Similarly, math symbols should be named as \math followed by the glyph name, for example \mathonequarter or \mathsterling.

Open questions:

Can we omit the text prefix for macros that are already established in short form (e.g. via babel's greek.ldf) and do not have a math counterpart?
Pro:
- Simpler.
- Ease of use (less typing, better readability of source text).
- Backwards compatible (many established macro names).
- There are examples of encoding-specific macros without the text-prefix, especially for letters:
  - \AE \DH \DJ \L \NG \OE \O \SS \TH \ae \dh \dj \guillemotleft \guillemotright \guilsinglleft \guilsinglright \i \j \l \ng \oe \o \quotedblbase \quotesinglbase \ss \th in T1 and OT1,
  - \CYR* and \cyr* in T2*
  - \heb* or no prefix in HE8
  - short descriptive names in the arabic part of PU (puarenc.def) (but e.g. \textkoppagreek in puenc.def)
- text prefix does not mark a macro as
  - encoding-specific
  - inserting a glyph
  as there are e.g. font-changing macros (\textbf, \textit) and encoding-changing macros (\textgreek, \textcyr).
Contra:
- Less consistent.
- text prefix marks a macro as confined to text mode
- Short forms can be defined in a package.
How to name accent macros (\DeclareTextAccent definitions)?
- Should \texttonos be an accent macro or a spacing character?
- How about a common prefix \accent... or postfix \...Accent?
How about glyph names with numbers and dots?
- Adobe recommends uni (or u) + Unicode number for all Unicode characters without established name.
  
  While it is possible to apply this scheme to TeX macros, it is hardly advisable: \koppa is far better readable than \csname uni03DF\endcsname.
If there exists a math-mode macro for a symbol, the corresponding text macro should be formed by prepending text.

Example: The glyph name for the final sigma is sigma1, but the corresponding math-macro is \varsigma. IMO, the text symbol should be available as \textvarsigma and not \csname textsigma1\endcsname.

Could this become a general rule?
Problems:
- \varepsilon and \varphi math macros map to "GREEK SMALL LETTER *", while others map to "GREEK * SYMBOL" Unicode chars.

The Adobe Glyph List For New Fonts has names for many glyphs in the Greek and Coptic Unicode block, but not for Greek extended.

An alternative, more complete set of short mnemonic character names is the XML Entity Definitions for Characters W3C Recommendation from 01 April 2010.

For glyph names of the LGR encoding see e.g. CB.enc by Apostolos Syropoulos and xl-lgr.enc from the libertine (legacy) package. lgr.cmap provides a mapping to Unicode characters.

A full set of \text* symbol macros is defined in ucsencs.def from the ucs package.

Using the names from puenc.def ensures that the hyperref package will do the right conversion to a PDF-string (see greek-part-of-puenc.def).

For accent macros, this file uses Greek names like in Unicode and ucsencs.def (without text prefix). Accent macro names are Capitalized or CamelCase, as they are intended for use in packages or classes. For the end-user "symbol macros" (\~ \' \` \" \< \>) are provided.

Implementation

Read this file only once

Note

The use of \@ifundefined has the side-effect that the tested macro becomes defined and set to \relax (polluting the namespace and interfering with test via eTeX's \ifdefined). However, in this case no harm is done as the macro is defined by the identification below anyway.

\@ifundefined{ver@lgrxenc.def}
  {\message{setting up comprehensive LGR font encoding definitions.}}
  {\message{comprehensive LGR font encoding definitions already loaded}
   \expandafter\endinput % "return"
  }

Identification

\ProvidesFile{lgrxenc.def}
         [2012/07/03 v0.6 %
          comprehensive LGR Greek Font Encoding definitions]

Base setup

Declare the font encoding and substitutions. (from the file lgrenc.def that comes with the Babel package):

\DeclareFontEncoding{LGR}{}{}
\DeclareFontSubstitution{LGR}{cmr}{m}{n}
\DeclareErrorFont{LGR}{cmr}{m}{n}{10}

The \TextGreek command can be used to ensure that its argument is set in a font encoding with support for Greek. If the font encoding is already LGR, kerning between adjacent command calls (e.g. \TextGreek{A}\TextGreek{\Upsilon}) is preserved. This allows wrapping of compound Unicode character definitions.

\DeclareTextCommand{\TextGreek}{LGR}[1]{#1}

Text symbols

Greek Alphabet

Greek letters are accessible by the Latin transcription, but the mapping is specific to the LGR font encoding.

The \text* macros provide a way to access the symbols in any font encoding supporting Greek independent of the specific font encoding. Alternative Greek font encodings are LGI (ibycus) and PU (PDF Unicode used by hyperref for PDF metadata). The textalpha.sty package makes these macros available in any font encoding.

\DeclareTextSymbol{\textAlpha}{LGR}{65}
\DeclareTextSymbol{\textBeta}{LGR}{66}
\DeclareTextSymbol{\textGamma}{LGR}{71}
\DeclareTextSymbol{\textDelta}{LGR}{68}
\DeclareTextSymbol{\textEpsilon}{LGR}{69}
\DeclareTextSymbol{\textZeta}{LGR}{90}
\DeclareTextSymbol{\textEta}{LGR}{72}
\DeclareTextSymbol{\textTheta}{LGR}{74}
\DeclareTextSymbol{\textIota}{LGR}{73}
\DeclareTextSymbol{\textKappa}{LGR}{75}
\DeclareTextSymbol{\textLambda}{LGR}{76}
\DeclareTextSymbol{\textMu}{LGR}{77}
\DeclareTextSymbol{\textNu}{LGR}{78}
\DeclareTextSymbol{\textXi}{LGR}{88}
\DeclareTextSymbol{\textOmicron}{LGR}{79}
\DeclareTextSymbol{\textPi}{LGR}{80}
\DeclareTextSymbol{\textRho}{LGR}{82}
\DeclareTextSymbol{\textSigma}{LGR}{83}
\DeclareTextSymbol{\textTau}{LGR}{84}
\DeclareTextSymbol{\textUpsilon}{LGR}{85}
\DeclareTextSymbol{\textPhi}{LGR}{70}
\DeclareTextSymbol{\textChi}{LGR}{81}
\DeclareTextSymbol{\textPsi}{LGR}{89}
\DeclareTextSymbol{\textOmega}{LGR}{87}
%
\DeclareTextSymbol{\textalpha}{LGR}{97}
\DeclareTextSymbol{\textbeta}{LGR}{98}
\DeclareTextSymbol{\textgamma}{LGR}{103}
\DeclareTextSymbol{\textdelta}{LGR}{100}
\DeclareTextSymbol{\textepsilon}{LGR}{101}
\DeclareTextSymbol{\textzeta}{LGR}{122}
\DeclareTextSymbol{\texteta}{LGR}{104}
\DeclareTextSymbol{\texttheta}{LGR}{106}
\DeclareTextSymbol{\textiota}{LGR}{105}
\DeclareTextSymbol{\textkappa}{LGR}{107}
\DeclareTextSymbol{\textlambda}{LGR}{108}
\DeclareTextSymbol{\textmu}{LGR}{109}
\DeclareTextSymbol{\textnu}{LGR}{110}
\DeclareTextSymbol{\textxi}{LGR}{120}
\DeclareTextSymbol{\textomicron}{LGR}{111}
\DeclareTextSymbol{\textpi}{LGR}{112}
\DeclareTextSymbol{\textrho}{LGR}{114}
\DeclareTextCommand{\textsigma}{LGR}{s\noboundary} % σ
\DeclareTextSymbol{\textvarsigma}{LGR}{99}         % ς final sigma
\DeclareTextSymbol{\textautosigma}{LGR}{115}       % σ (ς at end of word)
\DeclareTextSymbol{\texttau}{LGR}{116}
\DeclareTextSymbol{\textupsilon}{LGR}{117}
\DeclareTextSymbol{\textphi}{LGR}{102}
\DeclareTextSymbol{\textchi}{LGR}{113}
\DeclareTextSymbol{\textpsi}{LGR}{121}
\DeclareTextSymbol{\textomega}{LGR}{119}

Additional Greek symbols

Ancient Greek Numbers (Athenian Numerals)

Names from the athnum package:

\DeclareTextSymbol{\PiDelta}{LGR}{2} % GREEK ACROPHONIC ATTIC FIFTY
\DeclareTextSymbol{\PiEta}{LGR}{3}   % GREEK ACROPHONIC ATTIC FIVE HUNDRED
\DeclareTextSymbol{\PiChi}{LGR}{4}   % GREEK ACROPHONIC ATTIC FIVE THOUSAND
\DeclareTextSymbol{\PiMu}{LGR}{5}    % GREEK ACROPHONIC ATTIC FIFTY THOUSAND

Names from xl-lgr.enc (Greek numerals):

\DeclareTextSymbol{\pentedeka}{LGR}{2}    % GREEK ACROPHONIC ATTIC FIFTY
\DeclareTextSymbol{\pentehekaton}{LGR}{3} % GREEK ACROPHONIC ATTIC FIVE HUNDRED
\DeclareTextSymbol{\penteqilioi}{LGR}{4}  % GREEK ACROPHONIC ATTIC FIVE THOUSAND
\DeclareTextSymbol{\pentemurioi}{LGR}{5}  % GREEK ACROPHONIC ATTIC FIFTY THOUSAND

Archaic letters

Names after babel's greek.ldf, teubner and hyperref's puenc.def:

\DeclareTextSymbol{\stigma}{LGR}{6}           % ϛ (greek.df, teubner)
\DeclareTextSymbol{\textstigmagreek}{LGR}{6}  % ϛ (puenc.def)
\DeclareTextSymbol{\varstigma}{LGR}{7}        % stigma variant (CB.enc, teubner)
% \DeclareTextSymbol{\vardigamma}{LGR}{7}     % digamma variant (greek.ldf)
\DeclareTextSymbol{\koppa}{LGR}{18}           % ϟ (greek small letter koppa)
\DeclareTextSymbol{\textkoppagreek}{LGR}{18}  % ϟ (puenc.def)
\DeclareTextSymbol{\qoppa}{LGR}{19}           % ϙ (archaic koppa)
\DeclareTextSymbol{\Qoppa}{LGR}{21}           % Ϙ (archaic Koppa)
\DeclareTextSymbol{\Stigma}{LGR}{22}          % ϹΤ ligature (teubner)
\DeclareTextSymbol{\textStigmagreek}{LGR}{22} % ϹΤ ligature (puenc.def)
% \DeclareTextSymbol{\Stigma}{LGR}{??}        % Ϛ
\DeclareTextSymbol{\Sampi}{LGR}{23}           % Ϡ
\DeclareTextSymbol{\textSampigreek}{LGR}{23}  % Ϡ (puenc.def)
\DeclareTextSymbol{\sampi}{LGR}{27}           % ϡ
\DeclareTextSymbol{\textsampigreek}{LGR}{27}  % ϡ (puend.def)
\DeclareTextSymbol{\anoteleia}{LGR}{38}       % ·
\DeclareTextSymbol{\erotimatiko}{LGR}{63}     % ;
% \digamma used by amsmath for math-macro:
\DeclareTextSymbol{\ddigamma}{LGR}{147}         % ϝ (greek.ldf)
\DeclareTextSymbol{\Digamma}{LGR}{195}          % Ϝ (greek.ldf)
\DeclareTextSymbol{\textdigamma}{LGR}{147}      % ϝ with "text" prefix
\DeclareTextSymbol{\textDigamma}{LGR}{195}      % Ϝ with "text" prefix
\DeclareTextSymbol{\textdigammagreek}{LGR}{147} % ϝ (puenc.def)
\DeclareTextSymbol{\textDigammagreek}{LGR}{195} % Ϝ (puenc.def)

numeral signs

Names from babel and teubner:

\DeclareTextSymbol{\anwtonos}{LGR}{254}     % ʹ (Dexia keraia)
\DeclareTextSymbol{\katwtonos}{LGR}{255}    % ͵ (Aristeri keraia)

alias names for compatibility with hyperref's puenc.def:

\DeclareTextSymbol{\textnumeralsigngreek}{LGR}{254}
\DeclareTextSymbol{\textnumeralsignlowergreek}{LGR}{255}

Other

Characters that also exist in other font encodings

Define them for LGR if there is a matching glyph, so that they work if LGR is the only chosen font encoding.
Use established macro names that match with other *enc.def files and textcomp.sty.

% all encodings: See usrguide.pdf, chapter 3.14 ff
\DeclareTextSymbol{\textendash}{LGR}{0}          % EN DASH
\DeclareTextSymbol{\textquoteleft}{LGR}{28}      % ‘
\DeclareTextSymbol{\textquoteright}{LGR}{29}     % ’
\DeclareTextSymbol{\textperiodcentered}{LGR}{46} % · = \textanoteleia
\DeclareTextSymbol{\textcompwordmark}{LGR}{118}  % ZERO WIDTH NO JOINER
\DeclareTextSymbol{\textemdash}{LGR}{127}        % EM DASH

% T1
\DeclareTextSymbol{\guillemotleft}{LGR}{123}     % «
\DeclareTextSymbol{\guillemotright}{LGR}{125}    % »

% TS1
\ProvideTextCommand{\textasciibreve}{LGR}{\char30\textcompwordmark}    % ˘
\ProvideTextCommand{\textasciimacron}{LGR}{\char31\textcompwordmark}   % ¯
\ProvideTextCommand{\textasciidieresis}{LGR}{\char34\textcompwordmark} % "
\ProvideTextCommand{\textasciiacute}{LGR}{\char39\textcompwordmark}    % '
\ProvideTextCommand{\textasciigrave}{LGR}{\char96\textcompwordmark}    % `
\DeclareTextCommand{\textasciitilde}{LGR}{\char126\textcompwordmark}   % ~
% \DeclareTextSymbol{\textohm}{LGR}{87}          % Ω (Ohm sign ≠ Omega)
\DeclareTextSymbol{\texteuro}{LGR}{24}           % € \euro in greek.ldf
\DeclareTextSymbol{\textpercent}{LGR}{37}        % %
\DeclareTextSymbol{\textperthousand}{LGR}{25}    % ‰ \permille in greek.ldf

% T3
\DeclareTextSymbol{\textschwa}{LGR}{26}          % ə

Babel's lgrenc.def has some definitions to prevent surprises with macros that expect a Latin script. These definitions are problematic in the font-encoding definition file as they

require \textlatin which is defined in babel.def,
overwrite TS1 symbols set as default by textcomp.sty.

%\ProvideTextCommand{\textcopyright}{LGR}{\textcircled{\textlatin{c}}}
%\ProvideTextCommand{\textregistered}{LGR}{\textcircled{\textlatin{\textsc r}}}
%\ProvideTextCommand{\texttrademark}{LGR}{\textsuperscript{\textlatin{TM}}}
%\ProvideTextCommand{\SS}{LGR}{\textlatin{SS}}

How about:

%\ProvideTextCommand{\SS}{LGR}{\UseTextSymbol{T1}{\SS}}
%\ProvideTextCommand{\textcopyright}{LGR}{{\UseTextSymbol{T1}{\textcopyright}}}
% ...?

Diacritics

Based on the teubner package by Claudio Beccari and the babel patch by Werner Lemberg but with composite diacritic definitions (iterative diacritics).

Advantages:

get accented characters without resorting to the ligature mechanism (allows proper kerning, cf. teubner-doc).
reduced probability of incompatibilities (compared to teubner diacritic macros).
input convention similar to LGR input encodings (just prepend a \).

simple diacritics

Define Greek diacritics as named macros with shortcut alias.

Direct defining of \< and \> fails with `! Missing $ inserted.' (clash with math definitions). Also, we need aliases for proper upcasing (cf. UPPERCASE below).

\DeclareTextAccent{\Dasia}{LGR}{60} % δασεῖα spiritus asper (rough breathing)
\DeclareTextAccent{\Psili}{LGR}{62} % ψιλή spiritus lenis (smooth breathing)
\DeclareTextAccent{\Tonos}{LGR}{39} % τόνος/ὀξεῖα tonos/oxia (acute)
\DeclareTextAccent{\Varia}{LGR}{96} % βαρεῖα (grave)
\DeclareTextAccent{\Perispomeni}{LGR}{126} % περισπωμένη (circonflex/tilde)
\DeclareTextAccent{\Dialytika}{LGR}{34} % διαλυτικά (diaeresis/trema)

\DeclareTextCommand{\<}{LGR}{\Dasia}
\DeclareTextCommand{\>}{LGR}{\Psili}
\DeclareTextCommand{\'}{LGR}{\Tonos}
\DeclareTextCommand{\`}{LGR}{\Varia}
\DeclareTextCommand{\~}{LGR}{\Perispomeni}
\DeclareTextCommand{\"}{LGR}{\Dialytika}

These are not required as the postfix ligature does not interfere with kerning:

\DeclareTextSymbol{\Ypogegrammeni}{LGR}{124} % "small" sub-iota
\DeclareTextSymbol{\Prosgegrammeni}{LGR}{8}  % "capital" sub-iota

for critical editions or classical Greek:

\DeclareTextAccent{\lowbreve}{LGR}{20} %   low breve
\DeclareTextAccent{\u}{LGR}{30} % breve
\DeclareTextAccent{\=}{LGR}{31} % macron

The characters at position 16 and 17 are used in the \nexus macro of the teubner package to form an extensible, hat-like bracket. In CB.enc, they are mapped to

16--MODIFIER LETTER LOW ACUTE ACCENT 17--MODIFIER LETTER LOW GRAVE ACCENT

but according to the documentation of Werner Lemberg's babel patch, they rather represent the left and right part of U+23E0 TOP TORTOISE SHELL BRACKET.

composite diacritics

Definitions:

%                  Unicode Name                     Teubner name
\DeclareTextAccent{\DasiaOxia}{LGR}{86}            % Ar
\DeclareTextAccent{\DasiaVaria}{LGR}{67}           % Gr
\DeclareTextAccent{\DasiaPerispomeni}{LGR}{64}     % Cr

\DeclareTextAccent{\PsiliOxia}{LGR}{94}            % As
\DeclareTextAccent{\PsiliVaria}{LGR}{95}           % Gs
\DeclareTextAccent{\PsiliPerispomeni}{LGR}{92}     % Cs

\DeclareTextAccent{\DialytikaTonos}{LGR}{35}       % Ad, tonos/oxia
\DeclareTextAccent{\DialytikaVaria}{LGR}{36}       % Gd
\DeclareTextAccent{\DialytikaPerispomeni}{LGR}{32} % Cd

Composition from simple diacritics (the composition with simple "transcription characters" is done for the shortcut marcros, otherwise it fails with \Makeuppercase):

\DeclareTextCompositeCommand{\Dialytika}{LGR}{\Tonos}{\DialytikaTonos}
\DeclareTextCompositeCommand{\"}{LGR}{'}{\DialytikaTonos}
\DeclareTextCompositeCommand{\"}{LGR}{\'}{\DialytikaTonos}
\DeclareTextCompositeCommand{\Dialytika}{LGR}{\Varia}{\DialytikaVaria}
\DeclareTextCompositeCommand{\"}{LGR}{`}{\DialytikaVaria}
\DeclareTextCompositeCommand{\"}{LGR}{\`}{\DialytikaVaria}
\DeclareTextCompositeCommand{\Dialytika}{LGR}{\Perispomeni}{\DialytikaPerispomeni}
\DeclareTextCompositeCommand{\"}{LGR}{~}{\DialytikaPerispomeni}
\DeclareTextCompositeCommand{\"}{LGR}{\~}{\DialytikaPerispomeni}

\DeclareTextCompositeCommand{\Tonos}{LGR}{\Dialytika}{\DialytikaTonos}
\DeclareTextCompositeCommand{\'}{LGR}{"}{\DialytikaTonos}
\DeclareTextCompositeCommand{\'}{LGR}{\"}{\DialytikaTonos}
\DeclareTextCompositeCommand{\Tonos}{LGR}{\Dasia}{\DasiaOxia}
\DeclareTextCompositeCommand{\'}{LGR}{<}{\DasiaOxia}
\DeclareTextCompositeCommand{\'}{LGR}{\<}{\DasiaOxia}
\DeclareTextCompositeCommand{\Tonos}{LGR}{\Psili}{\PsiliOxia}
\DeclareTextCompositeCommand{\'}{LGR}{>}{\PsiliOxia}
\DeclareTextCompositeCommand{\'}{LGR}{\>}{\PsiliOxia}

\DeclareTextCompositeCommand{\Varia}{LGR}{\Dialytika}{\DialytikaVaria}
\DeclareTextCompositeCommand{\`}{LGR}{"}{\DialytikaVaria}
\DeclareTextCompositeCommand{\`}{LGR}{\"}{\DialytikaVaria}
\DeclareTextCompositeCommand{\Varia}{LGR}{\Dasia}{\DasiaVaria}
\DeclareTextCompositeCommand{\`}{LGR}{<}{\DasiaVaria}
\DeclareTextCompositeCommand{\`}{LGR}{\<}{\DasiaVaria}
\DeclareTextCompositeCommand{\Varia}{LGR}{\Psili}{\PsiliVaria}
\DeclareTextCompositeCommand{\`}{LGR}{>}{\PsiliVaria}
\DeclareTextCompositeCommand{\`}{LGR}{\>}{\PsiliVaria}

\DeclareTextCompositeCommand{\Perispomeni}{LGR}{\Dialytika}{\DialytikaPerispomeni}
\DeclareTextCompositeCommand{\~}{LGR}{"}{\DialytikaPerispomeni}
\DeclareTextCompositeCommand{\~}{LGR}{\"}{\DialytikaPerispomeni}
\DeclareTextCompositeCommand{\Perispomeni}{LGR}{\Dasia}{\DasiaPerispomeni}
\DeclareTextCompositeCommand{\~}{LGR}{<}{\DasiaPerispomeni}
\DeclareTextCompositeCommand{\~}{LGR}{\<}{\DasiaPerispomeni}
\DeclareTextCompositeCommand{\Perispomeni}{LGR}{\Psili}{\PsiliPerispomeni}
\DeclareTextCompositeCommand{\~}{LGR}{>}{\PsiliPerispomeni}
\DeclareTextCompositeCommand{\~}{LGR}{\>}{\PsiliPerispomeni}

\DeclareTextCompositeCommand{\Psili}{LGR}{\Tonos}{\PsiliOxia}
\DeclareTextCompositeCommand{\>}{LGR}{'}{\PsiliOxia}
\DeclareTextCompositeCommand{\>}{LGR}{\'}{\PsiliOxia}
\DeclareTextCompositeCommand{\Psili}{LGR}{\Varia}{\PsiliVaria}
\DeclareTextCompositeCommand{\>}{LGR}{`}{\PsiliVaria}
\DeclareTextCompositeCommand{\>}{LGR}{\`}{\PsiliVaria}
\DeclareTextCompositeCommand{\Psili}{LGR}{\Perispomeni}{\PsiliPerispomeni}
\DeclareTextCompositeCommand{\>}{LGR}{~}{\PsiliPerispomeni}
\DeclareTextCompositeCommand{\>}{LGR}{\~}{\PsiliPerispomeni}

\DeclareTextCompositeCommand{\Dasia}{LGR}{\Tonos}{\DasiaOxia}
\DeclareTextCompositeCommand{\<}{LGR}{'}{\DasiaOxia}
\DeclareTextCompositeCommand{\<}{LGR}{\'}{\DasiaOxia}
\DeclareTextCompositeCommand{\Dasia}{LGR}{\Varia}{\DasiaVaria}
\DeclareTextCompositeCommand{\<}{LGR}{`}{\DasiaVaria}
\DeclareTextCompositeCommand{\<}{LGR}{\`}{\DasiaVaria}
\DeclareTextCompositeCommand{\Dasia}{LGR}{\Perispomeni}{\DasiaPerispomeni}
\DeclareTextCompositeCommand{\<}{LGR}{~}{\DasiaPerispomeni}
\DeclareTextCompositeCommand{\<}{LGR}{\~}{\DasiaPerispomeni}

Pre-composed letters with diacritics (from teubner with changed names of the composite accents):

\DeclareTextComposite{\Varia}{LGR}{a}{128}
\DeclareTextComposite{\Dasia}{LGR}{a}{129}
\DeclareTextComposite{\Psili}{LGR}{a}{130}
\DeclareTextComposite{\DasiaVaria}{LGR}{a}{131}
\DeclareTextComposite{\Tonos}{LGR}{a}{136}
\DeclareTextComposite{\DasiaOxia}{LGR}{a}{137}
\DeclareTextComposite{\PsiliOxia}{LGR}{a}{138}
\DeclareTextComposite{\PsiliVaria}{LGR}{a}{139}
\DeclareTextComposite{\Perispomeni}{LGR}{a}{144}
\DeclareTextComposite{\DasiaPerispomeni}{LGR}{a}{145}
\DeclareTextComposite{\PsiliPerispomeni}{LGR}{a}{146}
\DeclareTextComposite{\Varia}{LGR}{h}{152}
\DeclareTextComposite{\Dasia}{LGR}{h}{153}
\DeclareTextComposite{\Psili}{LGR}{h}{154}
\DeclareTextComposite{\Tonos}{LGR}{h}{160}
\DeclareTextComposite{\DasiaOxia}{LGR}{h}{161}
\DeclareTextComposite{\PsiliOxia}{LGR}{h}{162}
\DeclareTextComposite{\DasiaVaria}{LGR}{h}{163}
\DeclareTextComposite{\Perispomeni}{LGR}{h}{168}
\DeclareTextComposite{\DasiaPerispomeni}{LGR}{h}{169}
\DeclareTextComposite{\PsiliPerispomeni}{LGR}{h}{170}
\DeclareTextComposite{\PsiliVaria}{LGR}{h}{171}
\DeclareTextComposite{\Varia}{LGR}{w}{176}
\DeclareTextComposite{\Dasia}{LGR}{w}{177}
\DeclareTextComposite{\Psili}{LGR}{w}{178}
\DeclareTextComposite{\DasiaVaria}{LGR}{w}{179}
\DeclareTextComposite{\Tonos}{LGR}{w}{184}
\DeclareTextComposite{\DasiaOxia}{LGR}{w}{185}
\DeclareTextComposite{\PsiliOxia}{LGR}{w}{186}
\DeclareTextComposite{\PsiliVaria}{LGR}{w}{187}
\DeclareTextComposite{\Perispomeni}{LGR}{w}{192}
\DeclareTextComposite{\DasiaPerispomeni}{LGR}{w}{193}
\DeclareTextComposite{\PsiliPerispomeni}{LGR}{w}{194}
\DeclareTextComposite{\Varia}{LGR}{i}{200}
\DeclareTextComposite{\Dasia}{LGR}{i}{201}
\DeclareTextComposite{\Psili}{LGR}{i}{202}
\DeclareTextComposite{\DasiaVaria}{LGR}{i}{203}
\DeclareTextComposite{\Tonos}{LGR}{i}{208}
\DeclareTextComposite{\DasiaOxia}{LGR}{i}{209}
\DeclareTextComposite{\PsiliOxia}{LGR}{i}{210}
\DeclareTextComposite{\PsiliVaria}{LGR}{i}{211}
\DeclareTextComposite{\Perispomeni}{LGR}{i}{216}
\DeclareTextComposite{\DasiaPerispomeni}{LGR}{i}{217}
\DeclareTextComposite{\PsiliPerispomeni}{LGR}{i}{218}
\DeclareTextComposite{\Dialytika}{LGR}{i}{240}
\DeclareTextComposite{\DialytikaVaria}{LGR}{i}{241}
\DeclareTextComposite{\DialytikaTonos}{LGR}{i}{242}
\DeclareTextComposite{\DialytikaPerispomeni}{LGR}{i}{243}
\DeclareTextComposite{\Varia}{LGR}{u}{204}
\DeclareTextComposite{\Dasia}{LGR}{u}{205}
\DeclareTextComposite{\Psili}{LGR}{u}{206}
\DeclareTextComposite{\DasiaVaria}{LGR}{u}{207}
\DeclareTextComposite{\Tonos}{LGR}{u}{212}
\DeclareTextComposite{\DasiaOxia}{LGR}{u}{213}
\DeclareTextComposite{\PsiliOxia}{LGR}{u}{214}
\DeclareTextComposite{\PsiliVaria}{LGR}{u}{215}
\DeclareTextComposite{\Perispomeni}{LGR}{u}{220}
\DeclareTextComposite{\DasiaPerispomeni}{LGR}{u}{221}
\DeclareTextComposite{\PsiliPerispomeni}{LGR}{u}{222}
\DeclareTextComposite{\Dialytika}{LGR}{u}{244}
\DeclareTextComposite{\DialytikaVaria}{LGR}{u}{245}
\DeclareTextComposite{\DialytikaTonos}{LGR}{u}{246}
\DeclareTextComposite{\DialytikaPerispomeni}{LGR}{u}{247}
\DeclareTextComposite{\Varia}{LGR}{e}{224}
\DeclareTextComposite{\Dasia}{LGR}{e}{225}
\DeclareTextComposite{\Psili}{LGR}{e}{226}
\DeclareTextComposite{\DasiaVaria}{LGR}{e}{227}
\DeclareTextComposite{\Tonos}{LGR}{e}{232}
\DeclareTextComposite{\DasiaOxia}{LGR}{e}{233}
\DeclareTextComposite{\PsiliOxia}{LGR}{e}{234}
\DeclareTextComposite{\PsiliVaria}{LGR}{e}{235}
\DeclareTextComposite{\Varia}{LGR}{o}{228}
\DeclareTextComposite{\Dasia}{LGR}{o}{229}
\DeclareTextComposite{\Psili}{LGR}{o}{230}
\DeclareTextComposite{\DasiaVaria}{LGR}{o}{231}
\DeclareTextComposite{\Tonos}{LGR}{o}{236}
\DeclareTextComposite{\DasiaOxia}{LGR}{o}{237}
\DeclareTextComposite{\PsiliOxia}{LGR}{o}{238}
\DeclareTextComposite{\PsiliVaria}{LGR}{o}{239}
\DeclareTextComposite{\Dasia}{LGR}{r}{251}
\DeclareTextComposite{\Psili}{LGR}{r}{252}

Do the same for the \text* macros:

\DeclareTextComposite{\Varia}{LGR}{\textalpha}{128}
\DeclareTextComposite{\Dasia}{LGR}{\textalpha}{129}
\DeclareTextComposite{\Psili}{LGR}{\textalpha}{130}
\DeclareTextComposite{\DasiaVaria}{LGR}{\textalpha}{131}
\DeclareTextComposite{\Tonos}{LGR}{\textalpha}{136}
\DeclareTextComposite{\DasiaOxia}{LGR}{\textalpha}{137}
\DeclareTextComposite{\PsiliOxia}{LGR}{\textalpha}{138}
\DeclareTextComposite{\PsiliVaria}{LGR}{\textalpha}{139}
\DeclareTextComposite{\Perispomeni}{LGR}{\textalpha}{144}
\DeclareTextComposite{\DasiaPerispomeni}{LGR}{\textalpha}{145}
\DeclareTextComposite{\PsiliPerispomeni}{LGR}{\textalpha}{146}
\DeclareTextComposite{\Varia}{LGR}{\texteta}{152}
\DeclareTextComposite{\Dasia}{LGR}{\texteta}{153}
\DeclareTextComposite{\Psili}{LGR}{\texteta}{154}
\DeclareTextComposite{\Tonos}{LGR}{\texteta}{160}
\DeclareTextComposite{\DasiaOxia}{LGR}{\texteta}{161}
\DeclareTextComposite{\PsiliOxia}{LGR}{\texteta}{162}
\DeclareTextComposite{\DasiaVaria}{LGR}{\texteta}{163}
\DeclareTextComposite{\Perispomeni}{LGR}{\texteta}{168}
\DeclareTextComposite{\DasiaPerispomeni}{LGR}{\texteta}{169}
\DeclareTextComposite{\PsiliPerispomeni}{LGR}{\texteta}{170}
\DeclareTextComposite{\PsiliVaria}{LGR}{\texteta}{171}
\DeclareTextComposite{\Varia}{LGR}{\textomega}{176}
\DeclareTextComposite{\Dasia}{LGR}{\textomega}{177}
\DeclareTextComposite{\Psili}{LGR}{\textomega}{178}
\DeclareTextComposite{\DasiaVaria}{LGR}{\textomega}{179}
\DeclareTextComposite{\Tonos}{LGR}{\textomega}{184}
\DeclareTextComposite{\DasiaOxia}{LGR}{\textomega}{185}
\DeclareTextComposite{\PsiliOxia}{LGR}{\textomega}{186}
\DeclareTextComposite{\PsiliVaria}{LGR}{\textomega}{187}
\DeclareTextComposite{\Perispomeni}{LGR}{\textomega}{192}
\DeclareTextComposite{\DasiaPerispomeni}{LGR}{\textomega}{193}
\DeclareTextComposite{\PsiliPerispomeni}{LGR}{\textomega}{194}
\DeclareTextComposite{\Varia}{LGR}{\textiota}{200}
\DeclareTextComposite{\Dasia}{LGR}{\textiota}{201}
\DeclareTextComposite{\Psili}{LGR}{\textiota}{202}
\DeclareTextComposite{\DasiaVaria}{LGR}{\textiota}{203}
\DeclareTextComposite{\Tonos}{LGR}{\textiota}{208}
\DeclareTextComposite{\DasiaOxia}{LGR}{\textiota}{209}
\DeclareTextComposite{\PsiliOxia}{LGR}{\textiota}{210}
\DeclareTextComposite{\PsiliVaria}{LGR}{\textiota}{211}
\DeclareTextComposite{\Perispomeni}{LGR}{\textiota}{216}
\DeclareTextComposite{\DasiaPerispomeni}{LGR}{\textiota}{217}
\DeclareTextComposite{\PsiliPerispomeni}{LGR}{\textiota}{218}
\DeclareTextComposite{\Dialytika}{LGR}{\textiota}{240}
\DeclareTextComposite{\DialytikaVaria}{LGR}{\textiota}{241}
\DeclareTextComposite{\DialytikaTonos}{LGR}{\textiota}{242}
\DeclareTextComposite{\DialytikaPerispomeni}{LGR}{\textiota}{243}
\DeclareTextComposite{\Varia}{LGR}{\textupsilon}{204}
\DeclareTextComposite{\Dasia}{LGR}{\textupsilon}{205}
\DeclareTextComposite{\Psili}{LGR}{\textupsilon}{206}
\DeclareTextComposite{\DasiaVaria}{LGR}{\textupsilon}{207}
\DeclareTextComposite{\Tonos}{LGR}{\textupsilon}{212}
\DeclareTextComposite{\DasiaOxia}{LGR}{\textupsilon}{213}
\DeclareTextComposite{\PsiliOxia}{LGR}{\textupsilon}{214}
\DeclareTextComposite{\PsiliVaria}{LGR}{\textupsilon}{215}
\DeclareTextComposite{\Perispomeni}{LGR}{\textupsilon}{220}
\DeclareTextComposite{\DasiaPerispomeni}{LGR}{\textupsilon}{221}
\DeclareTextComposite{\PsiliPerispomeni}{LGR}{\textupsilon}{222}
\DeclareTextComposite{\Dialytika}{LGR}{\textupsilon}{244}
\DeclareTextComposite{\DialytikaVaria}{LGR}{\textupsilon}{245}
\DeclareTextComposite{\DialytikaTonos}{LGR}{\textupsilon}{246}
\DeclareTextComposite{\DialytikaPerispomeni}{LGR}{\textupsilon}{247}
\DeclareTextComposite{\Varia}{LGR}{\textepsilon}{224}
\DeclareTextComposite{\Dasia}{LGR}{\textepsilon}{225}
\DeclareTextComposite{\Psili}{LGR}{\textepsilon}{226}
\DeclareTextComposite{\DasiaVaria}{LGR}{\textepsilon}{227}
\DeclareTextComposite{\Tonos}{LGR}{\textepsilon}{232}
\DeclareTextComposite{\DasiaOxia}{LGR}{\textepsilon}{233}
\DeclareTextComposite{\PsiliOxia}{LGR}{\textepsilon}{234}
\DeclareTextComposite{\PsiliVaria}{LGR}{\textepsilon}{235}
\DeclareTextComposite{\Varia}{LGR}{\textomicron}{228}
\DeclareTextComposite{\Dasia}{LGR}{\textomicron}{229}
\DeclareTextComposite{\Psili}{LGR}{\textomicron}{230}
\DeclareTextComposite{\DasiaVaria}{LGR}{\textomicron}{231}
\DeclareTextComposite{\Tonos}{LGR}{\textomicron}{236}
\DeclareTextComposite{\DasiaOxia}{LGR}{\textomicron}{237}
\DeclareTextComposite{\PsiliOxia}{LGR}{\textomicron}{238}
\DeclareTextComposite{\PsiliVaria}{LGR}{\textomicron}{239}
\DeclareTextComposite{\Dasia}{LGR}{r}{251}
\DeclareTextComposite{\Psili}{LGR}{r}{252}

Capital letters

In Greek, diacritics are omitted in all-uppercase words, but kept as part of an uppercase initial (written before rather than above the letter).

The diaytika should also always be used in all-uppercase words (even in cases where they are not needed when writing in lowercase)

—http://en.wikipedia.org/wiki/Capitalization

Title Case

Place diacritics before instead of above:

\DeclareTextCompositeCommand{\Dasia}{LGR}{A}{<A}
\DeclareTextCompositeCommand{\DasiaVaria}{LGR}{A}{<`A}
\DeclareTextCompositeCommand{\DasiaOxia}{LGR}{A}{<'A}
\DeclareTextCompositeCommand{\DasiaPerispomeni}{LGR}{A}{<\char126A}
\DeclareTextCompositeCommand{\Psili}{LGR}{A}{>A}
\DeclareTextCompositeCommand{\PsiliVaria}{LGR}{A}{>`A}
\DeclareTextCompositeCommand{\PsiliOxia}{LGR}{A}{>'A}
\DeclareTextCompositeCommand{\PsiliPerispomeni}{LGR}{A}{>\char126A}
\DeclareTextCompositeCommand{\Tonos}{LGR}{A}{'A}
\DeclareTextCompositeCommand{\Varia}{LGR}{A}{`A}

\DeclareTextCompositeCommand{\Dasia}{LGR}{E}{<E}
\DeclareTextCompositeCommand{\DasiaOxia}{LGR}{E}{<'E}
\DeclareTextCompositeCommand{\DasiaVaria}{LGR}{E}{<`E}
\DeclareTextCompositeCommand{\Psili}{LGR}{E}{>E}
\DeclareTextCompositeCommand{\PsiliOxia}{LGR}{E}{>'E}
\DeclareTextCompositeCommand{\PsiliVaria}{LGR}{E}{>`E}
\DeclareTextCompositeCommand{\Tonos}{LGR}{E}{'E}
\DeclareTextCompositeCommand{\Varia}{LGR}{E}{`E}

\DeclareTextCompositeCommand{\Dasia}{LGR}{H}{<H}
\DeclareTextCompositeCommand{\DasiaVaria}{LGR}{H}{<`H}
\DeclareTextCompositeCommand{\DasiaOxia}{LGR}{H}{<'H}
\DeclareTextCompositeCommand{\DasiaPerispomeni}{LGR}{H}{<\char126H}
\DeclareTextCompositeCommand{\Psili}{LGR}{H}{>H}
\DeclareTextCompositeCommand{\PsiliVaria}{LGR}{H}{>`H}
\DeclareTextCompositeCommand{\PsiliOxia}{LGR}{H}{>'H}
\DeclareTextCompositeCommand{\PsiliPerispomeni}{LGR}{H}{>\char126H}
\DeclareTextCompositeCommand{\Tonos}{LGR}{H}{'H}
\DeclareTextCompositeCommand{\Varia}{LGR}{H}{`H}

\DeclareTextCompositeCommand{\Dasia}{LGR}{I}{<I}
\DeclareTextCompositeCommand{\DasiaVaria}{LGR}{I}{<`I}
\DeclareTextCompositeCommand{\DasiaOxia}{LGR}{I}{<'I}
\DeclareTextCompositeCommand{\DasiaPerispomeni}{LGR}{I}{<\char126I}
\DeclareTextCompositeCommand{\Psili}{LGR}{I}{>I}
\DeclareTextCompositeCommand{\PsiliVaria}{LGR}{I}{>`I}
\DeclareTextCompositeCommand{\PsiliOxia}{LGR}{I}{>'I}
\DeclareTextCompositeCommand{\PsiliPerispomeni}{LGR}{I}{>\char126I}
\DeclareTextCompositeCommand{\Tonos}{LGR}{I}{'I}
\DeclareTextCompositeCommand{\Varia}{LGR}{I}{`I}

\DeclareTextCompositeCommand{\Dasia}{LGR}{O}{<O}
\DeclareTextCompositeCommand{\DasiaVaria}{LGR}{O}{<`O}
\DeclareTextCompositeCommand{\DasiaOxia}{LGR}{O}{<'O}
\DeclareTextCompositeCommand{\Psili}{LGR}{O}{>O}
\DeclareTextCompositeCommand{\PsiliVaria}{LGR}{O}{>`O}
\DeclareTextCompositeCommand{\PsiliOxia}{LGR}{O}{>'O}
\DeclareTextCompositeCommand{\Tonos}{LGR}{O}{'O}
\DeclareTextCompositeCommand{\Varia}{LGR}{O}{`O}

\DeclareTextCompositeCommand{\Dasia}{LGR}{U}{<U}
\DeclareTextCompositeCommand{\DasiaVaria}{LGR}{U}{<`U}
\DeclareTextCompositeCommand{\DasiaOxia}{LGR}{U}{<'U}
\DeclareTextCompositeCommand{\DasiaPerispomeni}{LGR}{U}{<\char126U}
\DeclareTextCompositeCommand{\Tonos}{LGR}{U}{'U}
\DeclareTextCompositeCommand{\Varia}{LGR}{U}{`U}

\DeclareTextCompositeCommand{\Dasia}{LGR}{W}{<W}
\DeclareTextCompositeCommand{\DasiaVaria}{LGR}{W}{<`W}
\DeclareTextCompositeCommand{\DasiaOxia}{LGR}{W}{<'W}
\DeclareTextCompositeCommand{\DasiaPerispomeni}{LGR}{W}{<\char126W}
\DeclareTextCompositeCommand{\Psili}{LGR}{W}{>W}
\DeclareTextCompositeCommand{\PsiliVaria}{LGR}{W}{>`W}
\DeclareTextCompositeCommand{\PsiliOxia}{LGR}{W}{>'W}
\DeclareTextCompositeCommand{\PsiliPerispomeni}{LGR}{W}{>\char126W}
\DeclareTextCompositeCommand{\Tonos}{LGR}{W}{'W}
\DeclareTextCompositeCommand{\Varia}{LGR}{W}{`W}

Except for the dialytika:

\DeclareTextComposite{\Dialytika}{LGR}{I}{219}
\DeclareTextComposite{\Dialytika}{LGR}{U}{223}

Do the same for the \text* macros:

\DeclareTextCompositeCommand{\Dasia}{LGR}{\textAlpha}{<A}
\DeclareTextCompositeCommand{\DasiaVaria}{LGR}{\textAlpha}{<`A}
\DeclareTextCompositeCommand{\DasiaOxia}{LGR}{\textAlpha}{<'A}
\DeclareTextCompositeCommand{\DasiaPerispomeni}{LGR}{\textAlpha}{<\char126A}
\DeclareTextCompositeCommand{\Psili}{LGR}{\textAlpha}{>A}
\DeclareTextCompositeCommand{\PsiliVaria}{LGR}{\textAlpha}{>`A}
\DeclareTextCompositeCommand{\PsiliOxia}{LGR}{\textAlpha}{>'A}
\DeclareTextCompositeCommand{\PsiliPerispomeni}{LGR}{\textAlpha}{>\char126A}
\DeclareTextCompositeCommand{\Tonos}{LGR}{\textAlpha}{'A}
\DeclareTextCompositeCommand{\Varia}{LGR}{\textAlpha}{`A}

\DeclareTextCompositeCommand{\Dasia}{LGR}{\textEpsilon}{<E}
\DeclareTextCompositeCommand{\DasiaOxia}{LGR}{\textEpsilon}{<'E}
\DeclareTextCompositeCommand{\DasiaVaria}{LGR}{\textEpsilon}{<`E}
\DeclareTextCompositeCommand{\Psili}{LGR}{\textEpsilon}{>E}
\DeclareTextCompositeCommand{\PsiliOxia}{LGR}{\textEpsilon}{>'E}
\DeclareTextCompositeCommand{\PsiliVaria}{LGR}{\textEpsilon}{>`E}
\DeclareTextCompositeCommand{\Tonos}{LGR}{\textEpsilon}{'E}
\DeclareTextCompositeCommand{\Varia}{LGR}{\textEpsilon}{`E}

\DeclareTextCompositeCommand{\Dasia}{LGR}{\textEta}{<H}
\DeclareTextCompositeCommand{\DasiaVaria}{LGR}{\textEta}{<`H}
\DeclareTextCompositeCommand{\DasiaOxia}{LGR}{\textEta}{<'H}
\DeclareTextCompositeCommand{\DasiaPerispomeni}{LGR}{\textEta}{<\char126H}
\DeclareTextCompositeCommand{\Psili}{LGR}{\textEta}{>H}
\DeclareTextCompositeCommand{\PsiliVaria}{LGR}{\textEta}{>`H}
\DeclareTextCompositeCommand{\PsiliOxia}{LGR}{\textEta}{>'H}
\DeclareTextCompositeCommand{\PsiliPerispomeni}{LGR}{\textEta}{>\char126H}
\DeclareTextCompositeCommand{\Tonos}{LGR}{\textEta}{'H}
\DeclareTextCompositeCommand{\Varia}{LGR}{\textEta}{`H}

\DeclareTextCompositeCommand{\Dasia}{LGR}{\textIota}{<I}
\DeclareTextCompositeCommand{\DasiaVaria}{LGR}{\textIota}{<`I}
\DeclareTextCompositeCommand{\DasiaOxia}{LGR}{\textIota}{<'I}
\DeclareTextCompositeCommand{\DasiaPerispomeni}{LGR}{\textIota}{<\char126I}
\DeclareTextCompositeCommand{\Psili}{LGR}{\textIota}{>I}
\DeclareTextCompositeCommand{\PsiliVaria}{LGR}{\textIota}{>`I}
\DeclareTextCompositeCommand{\PsiliOxia}{LGR}{\textIota}{>'I}
\DeclareTextCompositeCommand{\PsiliPerispomeni}{LGR}{\textIota}{>\char126I}
\DeclareTextCompositeCommand{\Tonos}{LGR}{\textIota}{'I}
\DeclareTextCompositeCommand{\Varia}{LGR}{\textIota}{`I}

\DeclareTextCompositeCommand{\Dasia}{LGR}{\textOmicron}{<O}
\DeclareTextCompositeCommand{\DasiaVaria}{LGR}{\textOmicron}{<`O}
\DeclareTextCompositeCommand{\DasiaOxia}{LGR}{\textOmicron}{<'O}
\DeclareTextCompositeCommand{\Psili}{LGR}{\textOmicron}{>O}
\DeclareTextCompositeCommand{\PsiliVaria}{LGR}{\textOmicron}{>`O}
\DeclareTextCompositeCommand{\PsiliOxia}{LGR}{\textOmicron}{>'O}
\DeclareTextCompositeCommand{\Tonos}{LGR}{\textOmicron}{'O}
\DeclareTextCompositeCommand{\Varia}{LGR}{\textOmicron}{`O}

\DeclareTextCompositeCommand{\Dasia}{LGR}{\textUpsilon}{<U}
\DeclareTextCompositeCommand{\DasiaVaria}{LGR}{\textUpsilon}{<`U}
\DeclareTextCompositeCommand{\DasiaOxia}{LGR}{\textUpsilon}{<'U}
\DeclareTextCompositeCommand{\DasiaPerispomeni}{LGR}{\textUpsilon}{<\char126U}
\DeclareTextCompositeCommand{\Tonos}{LGR}{\textUpsilon}{'U}
\DeclareTextCompositeCommand{\Varia}{LGR}{\textUpsilon}{`U}

\DeclareTextCompositeCommand{\Dasia}{LGR}{\textOmega}{<W}
\DeclareTextCompositeCommand{\DasiaVaria}{LGR}{\textOmega}{<`W}
\DeclareTextCompositeCommand{\DasiaOxia}{LGR}{\textOmega}{<'W}
\DeclareTextCompositeCommand{\DasiaPerispomeni}{LGR}{\textOmega}{<\char126W}
\DeclareTextCompositeCommand{\Psili}{LGR}{\textOmega}{>W}
\DeclareTextCompositeCommand{\PsiliVaria}{LGR}{\textOmega}{>`W}
\DeclareTextCompositeCommand{\PsiliOxia}{LGR}{\textOmega}{>'W}
\DeclareTextCompositeCommand{\PsiliPerispomeni}{LGR}{\textOmega}{>\char126W}
\DeclareTextCompositeCommand{\Tonos}{LGR}{\textOmega}{'W}
\DeclareTextCompositeCommand{\Varia}{LGR}{\textOmega}{`W}

Except for the dialytika:

\DeclareTextComposite{\Dialytika}{LGR}{\textIota}{219}
\DeclareTextComposite{\Dialytika}{LGR}{\textUpsilon}{223}

UPPERCASE

@uclclist extension

If UPPERCASE (all-caps) is generated with \MakeUppercase, macro substitutions in the \@uclclist apply. This can be used to drop the diacritics (except dialytika).

Based on the babel patch and fontenc.sty. (The first two lines are TeX' way of writing uclclist += …):

\expandafter\def\expandafter\@uclclist\expandafter{%
   \@uclclist
    \Dasia\do@nothing
    \DasiaOxia\@hiatus
    \DasiaVaria\do@nothing
    \DasiaPerispomeni\do@nothing
    \Psili\@hiatus
    \PsiliOxia\@hiatus
    \PsiliVaria\@hiatus
    \PsiliPerispomeni\do@nothing
    \Tonos\@hiatus
    \Varia\do@nothing
    \DialytikaTonos\up@Dialytika
    \DialytikaVaria\up@Dialytika
    \DialytikaPerispomeni\up@Dialytika
    \Perispomeni\do@nothing
    \Ypogegrammeni\Prosgegrammeni
    %
    \textalpha  \textAlpha
    \textbeta   \textBeta
    \textgamma  \textGamma
    \textdelta  \textDelta
    \textepsilon\textEpsilon
    \textzeta   \textZeta
    \texteta    \textEta
    \texttheta  \textTheta
    \textiota   \textIota
    \textkappa  \textKappa
    \textlambda \textLambda
    \textmu     \textMu
    \textnu     \textNu
    \textxi     \textXi
    \textomicron\textOmicron
    \textpi     \textPi
    \textrho    \textRho
    \textvarsigma  \textSigma
    \textsigma     \textSigma
    \textautosigma \textSigma
    \texttau    \textTau
    \textupsilon\textUpsilon
    \textphi    \textPhi
    \textchi    \textChi
    \textpsi    \textPsi
    \textomega  \textOmega
    %
    \qoppa      \Qoppa
    \varstigma  \Stigma
    \stigma     \Stigma
    \sampi      \Sampi
    \ddigamma   \Digamma
}

Substitution macros

Drop diacritics

\DeclareTextCommand{\do@nothing}{LGR}[1]{#1}

(The argument processing ensures that kerning is preserved)

Keep dialytika.

Define an alias so that downcasing with \MakeLowercase does not convert a simple dialytika to a composite accent:

\DeclareTextCommand{\up@Dialytika}{LGR}{\Dialytika}

Mark hiatus

Tonos and dasia mark a hiatus (break-up of a diphtong) if placed on the first vowel of a diphthong (ΑΙ, ΑΥ, ΕΙ). A dialytika must be placed on the second vowel if they are dropped (άυλος → ΑΫΛΟΣ, μάινα → ΜΑΪΝΑ, κέικ → ΚΕΪΚ, ἀυπνία → ΑΫΠΝΙΑ):

\DeclareTextCommand{\@hiatus}{LGR}[1]{#1}
\DeclareTextCompositeCommand{\@hiatus}{LGR}{A}{\A@hiatus}
\DeclareTextCompositeCommand{\@hiatus}{LGR}{\textAlpha}{\A@hiatus}
\DeclareTextCompositeCommand{\@hiatus}{LGR}{E}{\E@hiatus}
\DeclareTextCompositeCommand{\@hiatus}{LGR}{\textEpsilon}{\E@hiatus}

Look ahead and place a diaeresis on Ι or Υ:

\DeclareTextCommand{\A@hiatus}{LGR}{%
  \LGR@ifnextchar{I}{A\"}{%
    \LGR@ifnextchar{U}{A\"}{%
      \LGR@ifnextchar{\textIota}{A\"}{%
        \LGR@ifnextchar{\textUpsilon}{A\"}{A}%
      }%
    }%
  }%
}
\DeclareTextCommand{\E@hiatus}{LGR}{%
  \LGR@ifnextchar{I}{E\"}{%
    \LGR@ifnextchar{U}{E\"}{%
      \LGR@ifnextchar{\textIota}{E\"}{%
        \LGR@ifnextchar{\textUpsilon}{E\"}{E}%
      }%
    }%
  }%
}

As \@ifnextchar gobbles spaces the lookahead macro definition from amsgen.sty is used:

This macro is a new version of LaTeX’s \@ifnextchar, macro that does not skip over spaces.

\ProvideTextCommand{\LGR@ifnextchar}{LGR}[3]{%
% \long\def\LGR@ifnextchar#1#2#3{%
  \let\reserved@d= #1%
  \def\reserved@a{#2}\def\reserved@b{#3}%
  \futurelet\@let@token\LGR@ifnch
}
\ProvideTextCommand{\LGR@ifnch}{LGR}{%
  \ifx\@let@token\reserved@d \let\reserved@b\reserved@a \fi
  \reserved@b
}

Unfortunately, the lookahead breaks kerning.

Alternatives tried:

CompositeCommands fail at the end of a macro, e.g. \emph{\'a}:

%\DeclareTextCommand{\A@hiatus}{LGR}{A}
%\DeclareTextCommand{\E@hiatus}{LGR}{E}

%\DeclareTextCompositeCommand{\A@hiatus}{LGR}{}{A}
%\DeclareTextCompositeCommand{\A@hiatus}{LGR}{I}{A\"I}
%\DeclareTextCompositeCommand{\A@hiatus}{LGR}{U}{A\"U}

The glyph No 12 is a special "Upcase Alpha" that in ligature with Y and I adds a diaresis to them. However, it seems that it has only kerning definitions for I and Y (as it is not intended for direct use):
```
%\DeclareTextComposite{\@hiatus}{LGR}{A}{12}
```
No such glyph exists for E but this is no problem as E does not require kerning anyway.