Add AM modulation support to parser and exporter

static/ast-parser.js

@@ -181,6 +181,7 @@ function buildInstrument(node) {
         volumes: null,
         timbre: null,
         fmModulations: [],
+        amModulations: [],
         rawChildren: [],
     };
 
@@ -201,6 +202,9 @@ function buildInstrument(node) {
             case 'FM.modulation':
                 instr.fmModulations.push({ ...child.props });
                 break;
+            case 'AM.modulation':
+                instr.amModulations.push({ ...child.props });
+                break;
             default:
                 instr.rawChildren.push(buildGeneric(child));
         }
@@ -253,6 +257,7 @@ function buildBasicProperties(node) {
         A: null, S: null, R: null,
         oscillator: null,
         fmModulations: [],
+        amModulations: [],
         rawChildren: [],
     };
 
@@ -271,6 +276,11 @@ function buildBasicProperties(node) {
             const envChild = child.children.find(c => c.slot === 'shape');
             if (envChild) fm.shape = buildShape(envChild);
             bp.fmModulations.push(fm);
+        } else if (child.parentSlot === 'AM' && child.slot === 'modulation') {
+            const am = { ...child.props };
+            const envChild = child.children.find(c => c.slot === 'shape');
+            if (envChild) am.shape = buildShape(envChild);
+            bp.amModulations.push(am);
         } else {
             bp.rawChildren.push(buildGeneric(child));
         }

static/exporter.js

@@ -47,6 +47,7 @@ function basicPropLines(bp) {
     const r = serializeShape(bp.R);
     if (r) lines.push(`R: "${r}"`);
     for (const fm of (bp.fmModulations ?? [])) lines.push(`FM: "${serializeFm(fm)}"`);
+    for (const am of (bp.amModulations ?? [])) lines.push(`AM: "${serializeFm(am)}"`);
     return lines;
 }
 
@@ -76,6 +77,7 @@ function variationLines(v) {
     const timbre = serializeShape(v.timbre);
     if (timbre) lines.push(`TIMBRE: "${timbre}"`);
     for (const fm of (v.fmModulations ?? [])) lines.push(`FM: "${serializeFm(fm)}"`);
+    for (const am of (v.amModulations ?? [])) lines.push(`AM: "${serializeFm(am)}"`);
     for (const sv of (v.subvariations ?? [])) lines.push(...variationLines(sv));
     return lines;
 }
@@ -89,7 +91,8 @@ function variationLines(v) {
 function instrCharacterLines(instr) {
     const variations = instr.variations ?? [];
     const hasRootProps = instr.basicProperties || instr.volumes || instr.timbre ||
-                         (instr.fmModulations ?? []).length > 0;
+                         (instr.fmModulations ?? []).length > 0 ||
+                         (instr.amModulations ?? []).length > 0;
     const syntheticRoot = hasRootProps
         ? {
             basicProperties: instr.basicProperties,
@@ -98,6 +101,7 @@ function instrCharacterLines(instr) {
             volumes: instr.volumes,
             timbre: instr.timbre,
             fmModulations: instr.fmModulations ?? [],
+            amModulations: instr.amModulations ?? [],
           }
         : null;