Graph updates; readme updates

1 files changed, 13 insertions, 33 deletions

diff --git a/chapter09/docs/09-graph2.svg b/chapter09/docs/09-graph2.svg
index a2484f5c..59ef5de1 100644
--- a/chapter09/docs/09-graph2.svg
+++ b/chapter09/docs/09-graph2.svg
@@ -1,4 +1,4 @@
-<svg aria-label="Compiler graph" width="618" height="572" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 618 572" style="font-family: sans-serif;"><style>
+<svg aria-label="Compiler graph" width="548" height="454" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 548 454" style="font-family: sans-serif;"><style>
     html, body { height:100%; margin:0; font-family:sans-serif; }
     .viewer { height:100%; display:grid; grid-template-rows:auto minmax(0,1fr) auto; }
     .source { padding:8px; border-bottom:1px solid #ccc; }
@@ -60,62 +60,42 @@
     .count { font-size:20px; min-width:35px; text-align:center; }
     #N { width:6ch; }
     #scrub { width:clamp(120px,35vw,600px); }
-  </style><defs><marker id="arrow-CTRL" viewBox="0 -4 8 8" refX="8" refY="0" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path d="M0,-4L8,0L0,4Z" fill="#b63838"/></marker><marker id="arrow-DATA" viewBox="0 -4 8 8" refX="8" refY="0" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path d="M0,-4L8,0L0,4Z" fill="#536477"/></marker><marker id="arrow-MEM" viewBox="0 -4 8 8" refX="8" refY="0" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path d="M0,-4L8,0L0,4Z" fill="#2867b2"/></marker><marker id="arrow-ASSOC" viewBox="0 -4 8 8" refX="8" refY="0" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path d="M0,-4L8,0L0,4Z" fill="#9396a3"/></marker><marker id="arrow-PARSER" viewBox="0 -4 8 8" refX="8" refY="0" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path d="M0,-4L8,0L0,4Z" fill="#7956a5"/></marker></defs><rect width="100%" height="100%" fill="rgb(250, 251, 252)"/><g><g class="regions" style="opacity: 1;"/><rect class="peep-area" rx="36" style="opacity: 0;"/><g class="edges"><path class="edge CTRL" id="e3i0" d="M104,471 C104,495 297,498 297,522" stroke="#b63838" marker-start="url(#arrow-CTRL)" style="opacity: 1;"><title>#3[0] → #18 · CTRL</title></path><path class="edge CTRL" id="e3i1" d="M256,471 C256,495 321,498 321,522" stroke="#b63838" marker-start="url(#arrow-CTRL)" style="opacity: 1;"><title>#3[1] → #24 · CTRL</title></path><path class="edge DATA" id="e8i1" d="M224,118 L224,128 L336,128 L336,166" stroke="#536477" marker-start="url(#arrow-DATA)" style="opacity: 1;"><title>#8[1] → #4 · DATA</title></path><path class="edge DATA" id="e8i2" d="M534,118 L534,148 L366,148 L366,166" stroke="#536477" marker-start="url(#arrow-DATA)" style="opacity: 1;"><title>#8[2] → #7 · DATA</title></path><path class="edge DATA" id="e9i1" d="M224,118 L224,128 L184,128 L184,166" stroke="#536477" marker-start="url(#arrow-DATA)" style="opacity: 1;"><title>#9[1] → #4 · DATA</title></path><path class="edge DATA" id="e9i2" d="M382,118 L382,138 L214,138 L214,166" stroke="#536477" marker-start="url(#arrow-DATA)" style="opacity: 1;"><title>#9[2] → #10 · DATA</title></path><path class="edge CTRL" id="e11i0" d="M104,118 L104,270" stroke="#b63838" marker-start="url(#arrow-CTRL)" style="opacity: 1;"><title>#11[0] → #1 · CTRL</title></path><path class="edge DATA" id="e11i1" d="M184,222 L184,270" stroke="#536477" marker-start="url(#arrow-DATA)" style="opacity: 1;"><title>#11[1] → #9 · DATA</title></path><path class="edge CTRL" id="e18i0" d="M84,370 L84,418" stroke="#b63838" marker-start="url(#arrow-CTRL)" style="opacity: 1;"><title>#18[0] → #5 · CTRL</title></path><path class="edge DATA" id="e18i1" d="M336,222 L336,232 L280,232 L280,380 L124,380 L124,418" stroke="#536477" marker-start="url(#arrow-DATA)" style="opacity: 1;"><title>#18[1] → #8 · DATA</title></path><path class="edge DATA" id="e20i1" d="M336,222 L336,232 L351,232 L351,284.6666666666667" stroke="#536477" marker-start="url(#arrow-DATA)" style="opacity: 1;"><title>#20[1] → #8 · DATA</title></path><path class="edge DATA" id="e20i2" d="M488,222 L488,232 L381,232 L381,284.6666666666667" stroke="#536477" marker-start="url(#arrow-DATA)" style="opacity: 1;"><title>#20[2] → #21 · DATA</title></path><path class="edge CTRL" id="e24i0" d="M204,370 L204,390 L236,390 L236,418" stroke="#b63838" marker-start="url(#arrow-CTRL)" style="opacity: 1;"><title>#24[0] → #6 · CTRL</title></path><path class="edge DATA" id="e24i1" d="M351,340.6666666666667 L351,390 L276,390 L276,418" stroke="#536477" marker-start="url(#arrow-DATA)" style="opacity: 1;"><title>#24[1] → #20 · DATA</title></path></g><g class="edge-hits"/><g class="parser" style="opacity: 1;"/><g class="nodes"><g class="node" id="n1" data-id="1" transform="translate(44,68)" style="opacity: 1;"><path class="box" d="M0,0H120V44H0Z" fill="#fff1c4"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>$ctrl</tspan><tspan class="node-id">  #1/0</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#1 $ctrl
-Projection 0 of #2
+  </style><defs><marker id="arrow-CTRL" viewBox="0 -4 8 8" refX="8" refY="0" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path d="M0,-4L8,0L0,4Z" fill="#b63838"/></marker><marker id="arrow-DATA" viewBox="0 -4 8 8" refX="8" refY="0" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path d="M0,-4L8,0L0,4Z" fill="#536477"/></marker><marker id="arrow-MEM" viewBox="0 -4 8 8" refX="8" refY="0" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path d="M0,-4L8,0L0,4Z" fill="#2867b2"/></marker><marker id="arrow-ASSOC" viewBox="0 -4 8 8" refX="8" refY="0" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path d="M0,-4L8,0L0,4Z" fill="#9396a3"/></marker><marker id="arrow-PARSER" viewBox="0 -4 8 8" refX="8" refY="0" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path d="M0,-4L8,0L0,4Z" fill="#7956a5"/></marker></defs><rect width="100%" height="100%" fill="rgb(250, 251, 252)"/><g><g class="regions" style="opacity: 1;"/><rect class="peep-area" rx="36" style="opacity: 0;"/><g class="edges"><path class="edge DATA" id="e8i1" d="M306,118 L306,166" stroke="#536477" marker-start="url(#arrow-DATA)" style="opacity: 1;"><title>#8[1] → #4 · DATA</title></path><path class="edge DATA" id="e8i2" d="M464,118 L464,123 Q464,128 459,128 L344,128 Q336,128 336,136 L336,166" stroke="#536477" marker-start="url(#arrow-DATA)" style="opacity: 1;"><title>#8[2] → #7 · DATA</title></path><path class="edge CTRL" id="e18i0" d="M177,222 L177,270" stroke="#b63838" marker-start="url(#arrow-CTRL)" style="opacity: 1;"><title>#18[0] → #5 · CTRL</title></path><path class="edge DATA" id="e18i1" d="M306,222 L306,227 Q306,232 301,232 L225,232 Q217,232 217,240 L217,270" stroke="#536477" marker-start="url(#arrow-DATA)" style="opacity: 1;"><title>#18[1] → #8 · DATA</title></path><path class="edge DATA" id="e20i1" d="M306,222 L306,227 Q306,232 311,232 L341,232 Q349,232 349,240 L349,270" stroke="#536477" marker-start="url(#arrow-DATA)" style="opacity: 1;"><title>#20[1] → #8 · DATA</title></path><path class="edge DATA" id="e20i2" d="M458,222 L458,227 Q458,232 453,232 L387,232 Q379,232 379,240 L379,270" stroke="#536477" marker-start="url(#arrow-DATA)" style="opacity: 1;"><title>#20[2] → #21 · DATA</title></path><path class="edge CTRL" id="e24i0" d="M65,326 L65,374" stroke="#b63838" marker-start="url(#arrow-CTRL)" style="opacity: 1;"><title>#24[0] → #6 · CTRL</title></path><path class="edge DATA" id="e24i1" d="M349,326 L349,331 Q349,336 344,336 L113,336 Q105,336 105,344 L105,374" stroke="#536477" marker-start="url(#arrow-DATA)" style="opacity: 1;"><title>#24[1] → #20 · DATA</title></path></g><g class="edge-hits"/><g class="parser" style="opacity: 1;"/><g class="nodes"><g class="node" id="n2" data-id="2" transform="translate(246,24)" style="opacity: 1;"><path class="box" d="M0,0H120V44H0Z" fill="#fff1c4"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>Start</tspan><tspan class="node-id">  #2</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#2 Start
 Type not computed
 
-[0] → #2  CTRL</title></g><g class="node" id="n2" data-id="2" transform="translate(44,24)" style="opacity: 1;"><path class="box" d="M0,0H240V44H0Z" fill="#fff1c4"/><text class="label" text-anchor="middle" x="120" y="18"><tspan>Start</tspan><tspan class="node-id">  #2</tspan></text><text class="type" text-anchor="middle" y="35" x="120"/><title>#2 Start
-Type not computed
-
-</title></g><g class="node" id="n3" data-id="3" transform="translate(273,522)" style="opacity: 1;"><path class="box" d="M0,0H72V26H0Z" fill="#fff1c4"/><text class="label" text-anchor="middle" x="36" y="17"><tspan>Stop</tspan><tspan class="node-id">  #3</tspan></text><text class="type" text-anchor="middle" y="35" x="36"/><title>#3 Stop
-Type not computed
-
-[0] → #18  CTRL
-[1] → #24  CTRL</title><circle class="port" cx="24" cy="0" r="3" fill="#536477"/><circle class="port" cx="48" cy="0" r="3" fill="#536477"/><text class="slot" x="24" y="-7" text-anchor="middle">0</text><text class="slot" x="48" y="-7" text-anchor="middle">1</text></g><g class="node" id="n4" data-id="4" transform="translate(164,68)" style="opacity: 1;"><path class="box" d="M0,0H120V44H0Z" fill="#edf3f7"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>arg</tspan><tspan class="node-id">  #4/1</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#4 arg
+</title></g><g class="node" id="n4" data-id="4" transform="translate(246,68)" style="opacity: 1;"><path class="box" d="M0,0H120V44H0Z" fill="#edf3f7"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>arg</tspan><tspan class="node-id">  #4/1</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#4 arg
 Projection 1 of #2
 Type not computed
 
-[0] → #2  DATA</title></g><g class="node" id="n5" data-id="5" transform="translate(24,320)" style="opacity: 1;"><path class="box" d="M0,0H120V44H0Z" fill="#fff1c4"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>True</tspan><tspan class="node-id">  #5/0</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#5 True
-Projection 0 of #11
-Type not computed
-
-[0] → #11  CTRL</title></g><g class="node" id="n6" data-id="6" transform="translate(144,320)" style="opacity: 1;"><path class="box" d="M0,0H120V44H0Z" fill="#fff1c4"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>False</tspan><tspan class="node-id">  #6/1</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#6 False
-Projection 1 of #11
+[0] → #2  DATA</title></g><g class="node" id="n5" data-id="5" transform="translate(139,190)" style="opacity: 1;"><path class="box" d="M0,0H75V26H0Z" fill="#fff1c4"/><text class="label" text-anchor="middle" x="37.5" y="17"><tspan>True</tspan><tspan class="node-id">  #5/0</tspan></text><text class="type" text-anchor="middle" y="35" x="37.5"/><title>#5 True
+Projection 0 of #0
 Type not computed
 
-[0] → #11  CTRL</title></g><g class="node" id="n7" data-id="7" transform="translate(474,68)" style="opacity: 1;"><path class="box" d="M14,0H106Q120,0 120,14V30Q120,44 106,44H14Q0,44 0,30V14Q0,0 14,0Z" fill="#edf3f7"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>#2</tspan><tspan class="node-id">  #7</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#7 #2
+</title></g><g class="node" id="n6" data-id="6" transform="translate(24,294)" style="opacity: 1;"><path class="box" d="M0,0H81V26H0Z" fill="#fff1c4"/><text class="label" text-anchor="middle" x="40.5" y="17"><tspan>False</tspan><tspan class="node-id">  #6/1</tspan></text><text class="type" text-anchor="middle" y="35" x="40.5"/><title>#6 False
+Projection 1 of #0
 Type not computed
 
-</title></g><g class="node" id="n8" data-id="8" transform="translate(276,172)" style="opacity: 1;"><path class="box" d="M14,0H106Q120,0 120,14V30Q120,44 106,44H14Q0,44 0,30V14Q0,0 14,0Z" fill="#edf3f7"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>*</tspan><tspan class="node-id">  #8</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#8 *
+</title></g><g class="node" id="n7" data-id="7" transform="translate(404,68)" style="opacity: 1;"><path class="box" d="M14,0H106Q120,0 120,14V30Q120,44 106,44H14Q0,44 0,30V14Q0,0 14,0Z" fill="#edf3f7"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>#2</tspan><tspan class="node-id">  #7</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#7 #2
 Type not computed
 
-[0] → —  DATA
-[1] → #4  DATA
-[2] → #7  DATA</title><circle class="port" cx="30" cy="-3" r="3" fill="white"/><circle class="port" cx="60" cy="-3" r="3" fill="#536477"/><circle class="port" cx="90" cy="-3" r="3" fill="#536477"/><text class="slot" x="30" y="-10" text-anchor="middle">0</text><text class="slot" x="60" y="-10" text-anchor="middle">1</text><text class="slot" x="90" y="-10" text-anchor="middle">2</text></g><g class="node" id="n9" data-id="9" transform="translate(124,172)" style="opacity: 1;"><path class="box" d="M14,0H106Q120,0 120,14V30Q120,44 106,44H14Q0,44 0,30V14Q0,0 14,0Z" fill="#edf3f7"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>&lt;</tspan><tspan class="node-id">  #9</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#9 &lt;
+</title></g><g class="node" id="n8" data-id="8" transform="translate(246,172)" style="opacity: 1;"><path class="box" d="M14,0H106Q120,0 120,14V30Q120,44 106,44H14Q0,44 0,30V14Q0,0 14,0Z" fill="#edf3f7"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>*</tspan><tspan class="node-id">  #8</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#8 *
 Type not computed
 
 [0] → —  DATA
 [1] → #4  DATA
-[2] → #10  DATA</title><circle class="port" cx="30" cy="-3" r="3" fill="white"/><circle class="port" cx="60" cy="-3" r="3" fill="#536477"/><circle class="port" cx="90" cy="-3" r="3" fill="#536477"/><text class="slot" x="30" y="-10" text-anchor="middle">0</text><text class="slot" x="60" y="-10" text-anchor="middle">1</text><text class="slot" x="90" y="-10" text-anchor="middle">2</text></g><g class="node" id="n10" data-id="10" transform="translate(322,68)" style="opacity: 1;"><path class="box" d="M14,0H106Q120,0 120,14V30Q120,44 106,44H14Q0,44 0,30V14Q0,0 14,0Z" fill="#edf3f7"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>#10</tspan><tspan class="node-id">  #10</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#10 #10
-Type not computed
-
-</title></g><g class="node" id="n11" data-id="11" transform="translate(24,276)" style="opacity: 1;"><path class="box" d="M0,0H240V44H0Z" fill="#fff1c4"/><text class="label" text-anchor="middle" x="120" y="18"><tspan>If</tspan><tspan class="node-id">  #11</tspan></text><text class="type" text-anchor="middle" y="35" x="120"/><title>#11 If
-Type not computed
-
-[0] → #1  CTRL
-[1] → #9  DATA</title><circle class="port" cx="80" cy="-3" r="3" fill="#536477"/><circle class="port" cx="160" cy="-3" r="3" fill="#536477"/><text class="slot" x="80" y="-10" text-anchor="middle">0</text><text class="slot" x="160" y="-10" text-anchor="middle">1</text></g><g class="node" id="n18" data-id="18" transform="translate(44,424)" style="opacity: 1;"><path class="box" d="M0,0H120V44H0Z" fill="#fff1c4"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>Return</tspan><tspan class="node-id">  #18</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#18 Return
+[2] → #7  DATA</title><circle class="port" cx="30" cy="-3" r="3" fill="white"/><circle class="port" cx="60" cy="-3" r="3" fill="#536477"/><circle class="port" cx="90" cy="-3" r="3" fill="#536477"/><text class="slot" x="30" y="-10" text-anchor="middle">0</text><text class="slot" x="60" y="-10" text-anchor="middle">1</text><text class="slot" x="90" y="-10" text-anchor="middle">2</text></g><g class="node" id="n18" data-id="18" transform="translate(137,276)" style="opacity: 1;"><path class="box" d="M0,0H120V44H0Z" fill="#fff1c4"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>Return</tspan><tspan class="node-id">  #18</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#18 Return
 Type not computed
 
 [0] → #5  CTRL
-[1] → #8  DATA</title><circle class="port" cx="40" cy="-3" r="3" fill="#536477"/><circle class="port" cx="80" cy="-3" r="3" fill="#536477"/><text class="slot" x="40" y="-10" text-anchor="middle">0</text><text class="slot" x="80" y="-10" text-anchor="middle">1</text></g><g class="node" id="n20" data-id="20" transform="translate(291,290.6666666666667)" style="opacity: 1;"><path class="box" d="M14,0H106Q120,0 120,14V30Q120,44 106,44H14Q0,44 0,30V14Q0,0 14,0Z" fill="#edf3f7"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>+</tspan><tspan class="node-id">  #20</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#20 +
+[1] → #8  DATA</title><circle class="port" cx="40" cy="-3" r="3" fill="#536477"/><circle class="port" cx="80" cy="-3" r="3" fill="#536477"/><text class="slot" x="40" y="-10" text-anchor="middle">0</text><text class="slot" x="80" y="-10" text-anchor="middle">1</text></g><g class="node" id="n20" data-id="20" transform="translate(289,276)" style="opacity: 1;"><path class="box" d="M14,0H106Q120,0 120,14V30Q120,44 106,44H14Q0,44 0,30V14Q0,0 14,0Z" fill="#edf3f7"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>+</tspan><tspan class="node-id">  #20</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#20 +
 Type not computed
 
 [0] → —  DATA
 [1] → #8  DATA
-[2] → #21  DATA</title><circle class="port" cx="30" cy="-3" r="3" fill="white"/><circle class="port" cx="60" cy="-3" r="3" fill="#536477"/><circle class="port" cx="90" cy="-3" r="3" fill="#536477"/><text class="slot" x="30" y="-10" text-anchor="middle">0</text><text class="slot" x="60" y="-10" text-anchor="middle">1</text><text class="slot" x="90" y="-10" text-anchor="middle">2</text></g><g class="node" id="n21" data-id="21" transform="translate(428,172)" style="opacity: 1;"><path class="box" d="M14,0H106Q120,0 120,14V30Q120,44 106,44H14Q0,44 0,30V14Q0,0 14,0Z" fill="#edf3f7"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>#1</tspan><tspan class="node-id">  #21</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#21 #1
+[2] → #21  DATA</title><circle class="port" cx="30" cy="-3" r="3" fill="white"/><circle class="port" cx="60" cy="-3" r="3" fill="#536477"/><circle class="port" cx="90" cy="-3" r="3" fill="#536477"/><text class="slot" x="30" y="-10" text-anchor="middle">0</text><text class="slot" x="60" y="-10" text-anchor="middle">1</text><text class="slot" x="90" y="-10" text-anchor="middle">2</text></g><g class="node" id="n21" data-id="21" transform="translate(398,172)" style="opacity: 1;"><path class="box" d="M14,0H106Q120,0 120,14V30Q120,44 106,44H14Q0,44 0,30V14Q0,0 14,0Z" fill="#edf3f7"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>#1</tspan><tspan class="node-id">  #21</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#21 #1
 Type not computed
 
-</title></g><g class="node" id="n24" data-id="24" transform="translate(196,424)" style="opacity: 1;"><path class="box" d="M0,0H120V44H0Z" fill="#fff1c4"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>Return</tspan><tspan class="node-id">  #24</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#24 Return
+</title></g><g class="node" id="n24" data-id="24" transform="translate(25,380)" style="opacity: 1;"><path class="box" d="M0,0H120V44H0Z" fill="#fff1c4"/><text class="label" text-anchor="middle" x="60" y="18"><tspan>Return</tspan><tspan class="node-id">  #24</tspan></text><text class="type" text-anchor="middle" y="35" x="60"/><title>#24 Return
 Type not computed
 
 [0] → #6  CTRL