Syntactic and Semantic Errors
There are two kinds of errors that Basis can find.
Syntax errors occur during the parsing of input code, and are caused by grammatically incorrect statements.
Typical errors might be an illegal character in the input, a missing operator, two operators in a row,
two statements on the same line with no intervening semicolon, unbalanced parentheses, a misplaced reserved word, etc.Semantic errors occur during the execution of the code, after it has been parsed as grammatically correct.
These have to do not with how statements are constructed, but with what they mean.
Such things as incorrect variable types or sizes, nonexistent variables, subscripts out of range, and the like, are semantic errors.
Basis is a single-pass parser, that is, it looks at its input only once.
It also is a one-look ahead parser, meaning that at the most it is never looking more than one symbol ahead of the current context.
By the time a syntax error has been detected, it is likely that a lot of the context information to the left of the error has already been lost.
The diagnostic information that Basis gives attempts to be as useful as possible,
but because of the very limited context information available, it is far from perfect.
Semantic errors are often possible to diagnose more precisely.
We have attempted to make the semantic error information supplied as useful as possible.
Sometimes some of the information is only useful to someone familiar with the internals of Basis;
but we hope that in most cases it will help you find your error.
Syntax Error:
error due to missing colon, semicolon, parenthesis, etc.
Syntax is the way in which we construct sentences by following principles and rules.
Example: In C++, it would be a syntax error to say
int x = "five";
This will not compile because it does not follow the syntax of the language and does not make any sense to the compiler.
Semantic Error:
it is a logical error. it is due to wrong logical statements.
Semantics is the interpretations of and meanings derived from the sentence transmission and understanding of the message.
Semantics errors are Logical, while Syntax errors are code errors.
Example: A semantic error would compile, but be incorrect logically:
const int pi = 12345;
Your program will likely compile and run without error but your results will be incorrect.
(Note that these types of errors are usually much harder to debug)
Syntactic and Semantic Errors的更多相关文章
- Type Systems
This section deals with more theoretical aspects of types. A type system is a set of rules used by a ...
- Understanding Tensorflow using Go
原文: https://pgaleone.eu/tensorflow/go/2017/05/29/understanding-tensorflow-using-go/ Tensorflow is no ...
- 2016年最新mac下vscode配置golang开发环境支持debug
网上目前还找不到完整的mac下golang环境配置支持,本人配置成功,现在整理分享出来. mac最好装下xcode,好像有依赖关系安装Homebrew打开终端窗口, 粘贴脚本执行/usr/bin/ru ...
- coffeescript 1.8.0 documents
CoffeeScript is a little language that compiles into JavaScript. Underneath that awkward Java-esque ...
- 6.00.1x Introduction to computation
6.00 Introduction to Computer Science and Programming • Goal: –Become skillful at ...
- Word2vec教程
Word2vec Tutorial RADIM ŘEHŮŘEK 2014-02-02GENSIM, PROGRAMMING157 COMMENTS I never got round to writi ...
- coursera课程Text Retrieval and Search Engines之Week 1 Overview
Week 1 OverviewHelp Center Week 1 On this page: Instructional Activities Time Goals and Objectives K ...
- 【DeepLearning】一些资料
记录下,有空研究. http://nlp.stanford.edu/projects/DeepLearningInNaturalLanguageProcessing.shtml http://nlp. ...
- Chapter 4 Syntax Analysis
Chapter 4 Syntax Analysis This chapter is devoted to parsing methods that are typically used in comp ...
随机推荐
- Swagger文档化restful接口
1.注解 @Api:用在类上,说明该类的作用. @ApiOperation:注解来给API增加方法说明. @ApiImplicitParams : 用在方法上包含一组参数说明. @ApiImplici ...
- Django之初始庐山真面目
Django可以说是基于Python语言的一款非常成熟的框架,其功能之强大,应用之广泛,开发之便捷,可以说每一个细节都值得一赞 最重要的是,Django其实是我们学习Python过程中非常重要的部分之 ...
- 使用Cobbler批量部署Linux和Windows:CentOS/Ubuntu批量安装(二)
通过前面服务端的部署,已经配置好了 Cobbler Server 端,接下来开始进行 CentOS/Ubuntu 的批量安装,在进行 CentOS/Ubuntu 批量安装时,也需要通过Cobbler来 ...
- python_ssh连接
首先下载paramikopip install paramiko查看并启动ssh服务service ssh status 添加用户:useradd -d /home/zet zetpasswd zet ...
- Axure RP 快速原型设计工具
Axure RP是美国Axure Software Solution公司旗舰产品,是一个专业的快速原型设计工具,让负责定义需求和规格.设计功能和界面的专家能够快速创建应用软件或Web网站的线框图 ...
- [How to]HBase集群备份方法
1.简介 当HBase数据库中存在非常重要的业务数据的时候为了保护数据的可以对数据进行备份处理.对于HBase来说从备份操作来看可分为离线备份和在线备份. 2. 前准备 在测试环境上准备有哦两套HBa ...
- Android 7.0 新增功能和api
Android 7.0 Nougat 为用户和开发者引入多种新功能.本文重点介绍面向开发者的新功能. 请务必查阅 Android 7.0 行为变更以了解平台变更可能影响您的应用的领域. 要详细了解 A ...
- vue之给a标签赋值
<li v-for="(bp,index) in bpLists"> <a class="bidPublicityTitle" :href=& ...
- PowerMockRunner和ActiveObjectsJUnitRunner
Jira的二次开发,需要作单元测试. 测试跟数据库连接的类,比如service类,需要在类上加@RunWith(ActiveObjectsJUnitRunner.class). 有时需要搭配mocki ...
- SSD安装记录
这两天配置SSD,折腾了一两天,终于搞定了,记录下自己遇到的大坑. 1.安装SSD 安装参考:http://blog.csdn.net/shawncheer/article/details/53227 ...