# GLSLParser

**Repository Path**: zhu-rongrong-1062/glslparser

## Basic Information

- **Project Name**: GLSLParser
- **Description**: 使用c++和递归下降法实现了GLSL的词法分析器和语法分析器
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2023-06-30
- **Last Updated**: 2023-06-30

## Categories & Tags

**Categories**: Uncategorized

**Tags**: glsl, parser

## README

# GLSLParser
#### 介绍
使用c++和递归下降法实现了GLSL的词法分析器和语法分析器


#### 软件架构
由两部分组成，为Lexer（词法分析器）和Parser（语法分析器）  
如果控制台输入的代码符合以下GLSL文法，则输出Accept，否则Reject


### 实现的GLSL文法
toplevel :=  
	version definition*

version :=  
	'#version' NUMBER

definition :=  
	function_definition                 
	global_variable_definition          

function_definition :=  
	function_prototype '{' sentence* '}'	

function_prototype :=  
	TYPE identifier '(' ')'  
	TYPE identifier '(' TYPE identifier (',' TYPE identifier)* ')'    

sentence :=  
	'{' sentence* '}'  				
	expression ';'	  				
	variable_definition ';'  
	'if' '(' expression ')' sentence  
	'if' '(' expression ')' sentence 'else' sentence  
	'for' '(' expression ';' expression ';' expression ')' sentence  
	'for' '(' variable_definition ';' expression ';' expression ')' sentence  
	';'  
	'return' ';'  
	'return' expression ';'  

variable_definition :=  
	TYPE identifier '=' expression  
	'const' TYPE identifier '=' expression  

expression :=    								
	expression '.x'  
	expression '.y'  
	expression '.z'  
	expression '.w'  
	TYPE '(' expression_list ')'  
	'{' expression_list '}'  
	'(' expression ')'  
	NUMBER  
	identifier  
	identifier '(' expression_list ')'  
	identifier '[' expression ']'  
	expression '++'  
	expression '--'  
	'++' expression  
	'--' expression  
	'+' expression  
	'-' expression  
	'~' expression  
	'!' expression  
	expression '*' expression      
	expression '/' expression  
	expression '%' expression  
	expression '+' expression  
	expression '-' expression  
	expression '<<' expression  
	expression '>>' expression  
	expression '>=' expression  
	expression '<=' expression  
	expression '>' expression  
	expression '<' expression  
	expression '==' expression  
	expression '!=' expression  
	expression '&' expression  
	expression '^' expression  
	expression '|' expression  
	expression '&&' expression  
	expression '^' expression  
	expression '||' expression  
	expression '?' expression ':' expression  
	expression '=' expression  
	expression '+=' expression  
	expression '-=' expression  
	expression '*=' expression  
	expression '/=' expression  
	expression '%=' expression  
	expression '<<=' expression  
	expression '>>=' expression  
	expression '||=' expression  
	expression '&&=' expression  
	expression '|=' expression  
	expression '&=' expression  
	expression ',' expression  



expression_list :=
	expression (',' expression)*
	/* empty */

global_variable_definition :=
（为简化翻译，带有layout的全局变量，无论其相关数值如何，全部翻译为外部(external)全局变量即可）  
	layout_defaults TYPE identifier ';'

layout_defaults :=           
	layout_uniform_defaults  
  	layout_in_defaults   
  	layout_out_defaults     

layout_uniform_defaults :=  
	layout_qualifier 'uniform'

layout_in_defaults :=  
	layout_qualifier 'in'

layout_out_defaults :=  
	layout_qualifier 'out'

layout_qualifier :=  
	'layout' '(' layout_qualifier_id_list ')'

layout_qualifier_id_list :=  
	layout_qualifier_id (',' layout_qualifier_id)*

layout_qualifier_id :=  
	layout_identidier  
	layout_identidier '=' NUMBER

layout_identidier :=  
	'location'  
	'binding'

TYPE包括以下类型：
void bool int float double vec2 vec3 vec4 mat2 mat3 mat4