@mapbox/expression-jamsession - npm Package Compare versions

Comparing version 0.1.0 to 0.2.0

CHANGELOG.md

 # Changelog
 
+## 0.2.0
+
+- **[BREAKING]** Export 2 functions: `expressionToFormula` and `formulaToExpression`, so the transformation can go both ways.
+
 ## 0.1.0
 
 - Initial release.

dist/index.js

@@ -64,3 +64,3 @@ 'use strict';
 
-function createExpression(input) {
+function formulaToExpression(input) {
   var ast = void 0;
@@ -77,2 +77,36 @@ try {
 
-module.exports = createExpression;
+function expressionToFormula(expression) {
+  var operator = expression[0];
+
+  var args = expression.slice(1).map(function (arg) {
+    if (typeof arg === 'string') {
+      return '"' + arg + '"';
+    }
+    if (!Array.isArray(arg)) {
+      return arg;
+    }
+    var argOperator = arg[0];
+    var argFormula = expressionToFormula(arg);
+    if (/^[+-]$/.test(argOperator) && /^[*/]$/.test(operator)) {
+      return '(' + argFormula + ')';
+    }
+    return argFormula;
+  });
+
+  if (operator === '+' || operator === '*' || operator === '-' || operator === '/') {
+    return '' + args.join(' ' + operator + ' ');
+  }
+
+  if (operator === 'concat') {
+    return args.join(' & ');
+  }
+
+  return operator + '(' + args.join(', ') + ')';
+}
+
+var index = {
+  formulaToExpression: formulaToExpression,
+  expressionToFormula: expressionToFormula
+};
+
+module.exports = index;

package.json

 {
   "name": "@mapbox/expression-jamsession",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "description": "Write Mapbox GL expressions in a more familiar, handwritable, spreadsheet-like, programming-like syntax.",
@@ -5,0 +5,0 @@ "main": "dist/index.js",

README.md

@@ -9,3 +9,3 @@ # @mapbox/expression-jamsession
 
-## Features
+## Formula syntax features
 
@@ -48,14 +48,19 @@ - Arithmetic operators (`+ - * /`) and parentheses work like in high school math, e.g. `((3 + 4) * 2) / 7`.
 
-## Caveats
+## Usage
 
-- You can use this library to create expressions that are syntactically acceptable but invalid as Mapbox GL expressions, e.g. `notARealExpression(true)` outputs `["notARealExpression", true]`.
+The module exports two functions so you can transform in both directions:
 
-## Usage
+- `formulaToExpression` transforms (string) formulas to (array) expressions.
+- `expressionToFormula` transforms expressions to formulas.
 
-Pass in a string formula and get an expression.
-
 ```js
-import createExpression from '@mapbox/expression-jamsession';
+import jamsession from '@mapbox/expression-jamsession';
 
-createExpression('3 + 4'); // ["+", 3, 4]
+jamsession.formulaToExpression("3 + 4"); // ["+", 3, 4]
+
+jamsession.expressionToFormula(["+", 3, 4]); // "3 + 4"
 ```
+
+## Caveats
+
+- You can use this library to create expressions that are syntactically acceptable but invalid as Mapbox GL expressions, e.g. `notARealExpression(true)` outputs `["notARealExpression", true]`.

No alert changes

Improved metrics

Total package byte prevSize

7838

increased by18.18%

Lines of code

87

increased by47.46%

Number of lines in readme file

65

increased by8.33%

No dependency changes