Method getType

src/backend/function-node.js:357–572

* Recursively looks up type for ast expression until it's found * @param ast * @returns {String|null}

(ast)

   * @returns {String|null}
   */
  getType(ast) {
    if (Array.isArray(ast)) {
      return this.getType(ast[ast.length - 1]);
    }
    switch (ast.type) {
      case 'BlockStatement':
        return this.getType(ast.body);
      case 'ArrayExpression':
        const childType = this.getType(ast.elements[0]);
        switch (childType) {
          case 'Array(2)':
          case 'Array(3)':
          case 'Array(4)':
            return `Matrix(${ast.elements.length})`;
        }
        return `Array(${ ast.elements.length })`;
      case 'Literal':
        const literalKey = this.astKey(ast);
        if (this.literalTypes[literalKey]) {
          return this.literalTypes[literalKey];
        }
        if (Number.isInteger(ast.value)) {
          return 'LiteralInteger';
        } else if (ast.value === true || ast.value === false) {
          return 'Boolean';
        } else {
          return 'Number';
        }
        case 'AssignmentExpression':
          return this.getType(ast.left);
        case 'CallExpression':
          if (this.isAstMathFunction(ast)) {
            return 'Number';
          }
          if (!ast.callee || !ast.callee.name) {
            if (ast.callee.type === 'SequenceExpression' && ast.callee.expressions[ast.callee.expressions.length - 1].property.name) {
              const functionName = ast.callee.expressions[ast.callee.expressions.length - 1].property.name;
              this.inferArgumentTypesIfNeeded(functionName, ast.arguments);
              return this.lookupReturnType(functionName, ast, this);
            }
            if (this.getVariableSignature(ast.callee, true) === 'this.color') {
              return null;
            }
            if (ast.callee.type === 'MemberExpression' && ast.callee.object && ast.callee.property && ast.callee.property.name && ast.arguments) {
              const functionName = ast.callee.property.name;
              this.inferArgumentTypesIfNeeded(functionName, ast.arguments);
              return this.lookupReturnType(functionName, ast, this);
            }
            throw this.astErrorOutput('Unknown call expression', ast);
          }
          if (ast.callee && ast.callee.name) {
            const functionName = ast.callee.name;
            this.inferArgumentTypesIfNeeded(functionName, ast.arguments);
            return this.lookupReturnType(functionName, ast, this);
          }
          throw this.astErrorOutput(`Unhandled getType Type "${ ast.type }"`, ast);
        case 'LogicalExpression':
          return 'Boolean';