Add mem free printing (I need it to verify a suspicion relating to a bug)

node_modules/lv_font_conv/lib/ranger.js

@@ -0,0 +1,51 @@
+// Merge ranges into single object
+
+'use strict';
+
+
+class Ranger {
+  constructor() {
+    this.data = {};
+  }
+
+  // input:
+  //  -r 0x1F450 - single value, dec or hex format
+  //  -r 0x1F450-0x1F470 - range
+  //  -r 0x1F450=>0xF005 - single glyph with mapping
+  //  -r 0x1F450-0x1F470=>0xF005 - range with mapping
+  add_range(font, start, end, mapped_start) {
+    let offset = mapped_start - start;
+    let output = [];
+
+    for (let i = start; i <= end; i++) {
+      this._set_char(font, i, i + offset);
+      output.push(i);
+    }
+
+    return output;
+  }
+
+  // input: characters to copy, e.g. '1234567890abcdef'
+  add_symbols(font, str) {
+    let output = [];
+
+    for (let chr of str) {
+      let code = chr.codePointAt(0);
+      this._set_char(font, code, code);
+      output.push(code);
+    }
+
+    return output;
+  }
+
+  _set_char(font, code, mapped_to) {
+    this.data[mapped_to] = { font, code };
+  }
+
+  get() {
+    return this.data;
+  }
+}
+
+
+module.exports = Ranger;