93 lines
2.6 KiB
Text
93 lines
2.6 KiB
Text
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%{
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#include <stdio.h>
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#define IDENTIFIER 100
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#define VALUE 101
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#define PLUS 102
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#define MINUS 103
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#define DIVIDE 104
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#define TIMES 105
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#define LESS 106
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#define GREATER 107
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#define LESSEQ 108
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#define GREATEREQ 109
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#define EQUALS 110
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#define NEQUALS 111
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#define AND 112
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#define OR 113
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#define NOT 114
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#define SEMICOLON 115
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#define ASSIGN 116
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#define OPENPAREM 117
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#define ENDPAREM 118
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#define BEGINTOK 119
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#define END 120
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#define IF 121
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#define THEN 122
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#define ELSE 123
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#define WHILE 124
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#define DO 125
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#define PRINT 126
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#define INPUT 127
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#define COMMENT 128
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#define ERROR 129
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#define WHITESPACE 130
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%}
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ALPHA [a-zA-Z]
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DIGIT [0-9]
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%option noyywrap
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%%
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"+" {return PLUS; }
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"-" {return MINUS;}
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"/" {return DIVIDE;}
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"*" {return TIMES;}
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"!" {return NOT;}
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"(" {return OPENPAREM;}
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")" {return ENDPAREM;}
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";" {return SEMICOLON;}
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%.*\n {return COMMENT;}
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"<" {return LESS;}
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">" {return GREATER;}
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"<=" {return LESSEQ;}
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">=" {return GREATEREQ;}
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"==" {return EQUALS;}
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"!=" {return NEQUALS;}
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"&&" {return AND;}
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"||" {return OR;}
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":=" {return ASSIGN;}
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"if" {return IF;}
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"do" {return DO;}
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"end" {return END;}
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"then" {return THEN;}
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"else" {return ELSE;}
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"begin" {return BEGINTOK;}
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"while" {return WHILE;}
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"print" {return PRINT;}
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"input" {return INPUT;}
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{DIGIT}*"."?{DIGIT}+ {return VALUE;}
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[_a-zA-Z][_a-zA-Z0-9]* {return IDENTIFIER;}
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[ \n\t\r]+ {return WHITESPACE;}
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. {printf("Syntax Error! Received: %s\n", yytext); return ERROR;}
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%%
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int main(int argc, char* argv[]) {
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if (argc != 2) {
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printf("Incorrect number of arguments passed. Expected %d, got %d.\n", 1, argc - 1);
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printf("Usage: lexer [program_name].sl\n");
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exit(-1);
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}
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stdin = fopen(argv[1], "r");
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int token;
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do {
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token = yylex();
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if (token == ERROR) {
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exit(-1);
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}
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// Ignore Comments and Whitespace
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if (token != COMMENT && token != WHITESPACE) {
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printf("%d\n", token);
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}
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} while(token != 0);
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return 0;
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}
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