serverless-offline-msk
Version:
A serverless offline plugin that enables AWS MSK events
94 lines (74 loc) • 2.44 kB
JavaScript
module.exports = function(Velocity, utils){
/**
* expression support, include math, logic, compare expression
*/
utils.mixin(Velocity.prototype, {
/**
* 表达式求值，表达式主要是数学表达式，逻辑运算和比较运算，到最底层数据结构，
* 基本数据类型，使用 getLiteral求值，getLiteral遇到是引用的时候，使用
* getReferences求值
*/
getExpression: function(ast){
var exp = ast.expression;
var ret;
if (ast.type === 'math') {
switch(ast.operator) {
case '+':
ret = this.getExpression(exp[0]) + this.getExpression(exp[1]);
break;
case '-':
ret = this.getExpression(exp[0]) - this.getExpression(exp[1]);
break;
case '/':
ret = this.getExpression(exp[0]) / this.getExpression(exp[1]);
break;
case '%':
ret = this.getExpression(exp[0]) % this.getExpression(exp[1]);
break;
case '*':
ret = this.getExpression(exp[0]) * this.getExpression(exp[1]);
break;
case '||':
ret = this.getExpression(exp[0]) || this.getExpression(exp[1]);
break;
case '&&':
ret = this.getExpression(exp[0]) && this.getExpression(exp[1]);
break;
case '>':
ret = this.getExpression(exp[0]) > this.getExpression(exp[1]);
break;
case '<':
ret = this.getExpression(exp[0]) < this.getExpression(exp[1]);
break;
case '==':
ret = this.getExpression(exp[0]) == this.getExpression(exp[1]);
break;
case '>=':
ret = this.getExpression(exp[0]) >= this.getExpression(exp[1]);
break;
case '<=':
ret = this.getExpression(exp[0]) <= this.getExpression(exp[1]);
break;
case '!=':
ret = this.getExpression(exp[0]) != this.getExpression(exp[1]);
break;
case 'minus':
ret = - this.getExpression(exp[0]);
break;
case 'not':
ret = !this.getExpression(exp[0]);
break;
case 'parenthesis':
ret = this.getExpression(exp[0]);
break;
default:
return;
// code
}
return ret;
} else {
return this.getLiteral(ast);
}
}
});
};