How to make a lexical analyzer in C++?
You required two files;
- t4tutorials.cpp
- T4Tutorials.txt
Try to save both files in one folder to make it simpler.
Source Code of the lexical analyzer to detect tokens in C++.
code of t4tutorials.cpp
|
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#include<iostream> #include<fstream> #include<stdlib.h> #include<string.h> #include<ctype.h> using namespace std; int isKeyword(char buffer[]){ char keywords[40][40] = {"switch","typedef","union", "unsigned","void","long","register","short","signed", "sizeof","static","volatile","while""auto","break","case","char","const","continue","default", "do","double","enum","extern","return","struct","float","for","goto", "if","int","else"}; int i, T4Tutorials_Flag = 0; for(i = 0; i < 32; ++i){ if(strcmp(keywords[i], buffer) == 0){ T4Tutorials_Flag = 1; break; } } return T4Tutorials_Flag; } int main(){ char ch, buffer[15], operators[] = "+-*/%="; ifstream fin("T4Tutorials.txt"); int i,j=0; if(!fin.is_open()){ cout<<"Sorrys: issue in opening the file"<<endl; exit(0); } while(!fin.eof()){ ch = fin.get(); for(i = 0; i < 6; ++i){ if(ch == operators[i]) cout<<ch<<" : operator"<<endl; } if(isalnum(ch)){ buffer[j++] = ch; } else if((ch == ' ' || ch == '\n') && (j != 0)){ buffer[j] = '\0'; j = 0; if(isKeyword(buffer) == 1) cout<<buffer<<" is keyword"<<endl; else cout<<buffer<<" : indentifier"<<endl; } } fin.close(); return 0; } |
code of t4tutorials.txt
void main(
{
int x, y, z;
z=x+y;
}
Output
C++ code of Lexical analyzer [download]
How to make a lexical analyzer in C?
You required two files;
- t4tutorials.c
- T4Tutorials.txt
Try to save both files in one folder to make it simpler.
Source Code of the lexical analyzer to detect tokens in C++.
code of t4tutorials.c
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 |
#include<stdio.h> #include<stdlib.h> #include<string.h> #include<ctype.h> int isKeyword(char buffer[]){ char keywords[40][40] = {"switch","typedef","union", "unsigned","void","long","register","short","signed", "sizeof","static","volatile","while""auto","break","case","char","const","continue","default", "do","double","enum","extern","return","struct","float","for","goto", "if","int","else"}; int i, T4Tutorials_Flag = 0; for(i = 0; i < 32; ++i){ if(strcmp(keywords[i], buffer) == 0){ T4Tutorials_Flag = 1; break; } } return T4Tutorials_Flag; } int main(){ char ch, buffer[15], operators[] = "+-*/%="; FILE *fp; int i,j=0; fp = fopen("t4tutorials.txt","r"); if(fp == NULL){ printf("Sorrys: issue in opening the file\n"); exit(0); } while((ch = fgetc(fp)) != EOF){ for(i = 0; i < 6; ++i){ if(ch == operators[i]) printf("%c : operator\n", ch); } if(isalnum(ch)){ buffer[j++] = ch; } else if((ch == ' ' || ch == '\n') && (j != 0)){ buffer[j] = '\0'; j = 0; if(isKeyword(buffer) == 1) printf("%s : keyword\n", buffer); else printf("%s :indentifier\n", buffer); } } fclose(fp); return 0; } |
code of t4tutorials.txt
void main(
{
int x, y, z;
z=x+y;
}
Output
C code to make lexical analyzer [download]
CEO @ T4Tutorials.com
I welcome to all of you if you want to discuss about any topic. Researchers, teachers and students are allowed to use the content for non commercial offline purpose. Further, You must use the reference of the website, if you want to use the partial content for research purpose.
I welcome to all of you if you want to discuss about any topic. Researchers, teachers and students are allowed to use the content for non commercial offline purpose. Further, You must use the reference of the website, if you want to use the partial content for research purpose.
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