Horizontal edges crossing vertical edges

Thank you to Muzimuzhi for his comment. In case it could be useful to someone else, I am posting below the full code of what I was expecting, based on Muzimuzhi comment:

documentclass[12pt]{book}
usepackage[paperwidth=16cm, paperheight=24cm]{geometry}
usepackage[T1]{fontenc}
usepackage[french]{babel}
usepackage{tabularx,ragged2e}
newcolumntype{R}{>{RaggedLeft}X}

usepackage{tikz}

usetikzlibrary{arrows,automata,matrix,positioning,calc}

begin{document}
    begin{tikzpicture} [every node/.style={block}, block/.style={minimum height=1.5em,outer sep=0pt,draw,rectangle,node distance=1 cm}]
            node (A){Source code};
            node (B) [below=of A] {Lexical analysis};
            node (C) [below=of B] {Syntaxical analysis};
            node (D) [below=of C] {Semantical analysis};
            node (E) [below=of D] {Code generation};
            node (F) [below=of E] {Code optimization};
            node (G) [below=of F] {Code generation};
            node (H) [below=of G] {Object code};

            path[->] (A) edge (B);
            path[->] (B) edge (C);
            path[->] (C) edge (D);
            path[->] (D) edge (E);
            path[->] (E) edge (F);
            path[->] (F) edge (G);
            path[->] (G) edge (H);

            draw[->] ($ (A)!.5!(B) $) -- +(3, 0) node[align=center, right] {textmore text};
            draw[->] ($ (B)!.5!(C) $) -- +(3, 0) node[align=center, right] {textmore text};
            draw[->] ($ (C)!.5!(D) $) -- +(3, 0) node[align=center, right] {textmore text};
            draw[->] ($ (D)!.5!(E) $) -- +(3, 0) node[align=center, right] {textmore text};
            draw[->] ($ (E)!.5!(F) $) -- +(3, 0) node[align=center, right] {textmore text};
            draw[->] ($ (F)!.5!(G) $) -- +(3, 0) node[align=center, right] {textmore text};
            draw[->] ($ (G)!.5!(H) $) -- +(3, 0) node[align=center, right] {textmore text};

    end{tikzpicture}
end{document}