Address review comments:

- "FormattedExpression" -> "FormatExpression" (reasoning: the expression itself is a verb, the result is a noun)
- Remove dead/debug code
- Add comments

build/generate-style-code.js

@@ -5,7 +5,6 @@ const fs = require('fs');
 const ejs = require('ejs');
 const spec = require('../src/style-spec/reference/v8');
 const Color = require('../src/style-spec/util/color');
-const {Formatted} = require('../src/style-spec/expression/definitions/formatted');
 
 global.camelize = function (str) {
     return str.replace(/(?:^|-)(.)/g, function (_, x) {

src/style-spec/expression/definitions/formatted.js

@@ -50,7 +50,7 @@ type FormattedSectionExpression = {
     font: Expression | null;
 }
 
-export class FormattedExpression implements Expression {
+export class FormatExpression implements Expression {
     type: Type;
     sections: Array<FormattedSectionExpression>;
 
@@ -94,7 +94,7 @@ export class FormattedExpression implements Expression {
             sections.push({text, scale, font});
         }
 
-        return new FormattedExpression(sections);
+        return new FormatExpression(sections);
     }
 
     evaluate(ctx: EvaluationContext) {

src/style-spec/expression/definitions/index.js

@@ -26,7 +26,7 @@ import {
     GreaterThanOrEqual
 } from './comparison';
 import { CollatorExpression } from './collator';
-import { Formatted, FormattedExpression } from './formatted';
+import { Formatted, FormatExpression } from './formatted';
 import Length from './length';
 
 import type { Type } from '../types';
@@ -47,7 +47,7 @@ const expressions: ExpressionRegistry = {
     'case': Case,
     'coalesce': Coalesce,
     'collator': CollatorExpression,
-    'format': FormattedExpression,
+    'format': FormatExpression,
     'interpolate': Interpolate,
     'length': Length,
     'let': Let,

src/style-spec/validate/validate.js

@@ -69,9 +69,6 @@ export default function validate(options) {
         const valid = validateObject(extend({}, options, {
             valueSpec: valueSpec.type ? styleSpec[valueSpec.type] : valueSpec
         }));
-        if (!valid) {
-            console.log("not valid");
-        }
         return valid;
     }
 }

src/symbol/shaping.js

@@ -44,7 +44,7 @@ type TextJustify = 'left' | 'center' | 'right';
 
 class TaggedString {
     text: string;
-    sectionIndex: Array<number>
+    sectionIndex: Array<number> // maps each character in 'text' to its corresponding entry in 'sections'
     sections: Array<{ scale: number, fontStack: string }>
 
     constructor() {

src/symbol/transform_text.js

@@ -24,7 +24,6 @@ function transformText(text: string, layer: SymbolStyleLayer, feature: Feature)
 
 export default function(text: string | Formatted, layer: SymbolStyleLayer, feature: Feature) {
     if (text instanceof Formatted) {
-        // OK to transform in place?
         text.sections.forEach(section => {
             section.text = transformText(section.text, layer, feature);
         });