78 lines
1.7 KiB
C
78 lines
1.7 KiB
C
#include <ctype.h>
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#include <limits.h>
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#include <math.h>
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#include <stdio.h>
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#include "include/lexer.h"
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int acc_int(int c) {
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int value = c - '0';
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while (isdigit(*inp)) {
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value = value * 10 + (*inp - '0'); // Accumulate value.
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inp++;
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}
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return value;
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}
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double acc_float(int c) {
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int dplaces = 0;
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double value = (double)(c - '0');
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// Grab everything prior to '.'.
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while (isdigit(*inp)) {
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value = value * 10 + (*inp - '0'); // Accumulate value.
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inp++;
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}
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if (*inp == '.') {
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inp++;
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while (isdigit(*inp)) {
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// TODO:
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// Accumulate as int, divide once at end.
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// value = value + (((double)(*inp - '0'))/pow(10.0l,
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// (double)(inp-oinp))); // Accumulate value.
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value = value * 10 + (*inp - '0'); // Accumulate value.
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dplaces++;
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inp++;
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}
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value = value / pow(10, dplaces);
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}
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// > 1.20000
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// = 1.0 + 2/10
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// > 1.23
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// = 1.2 + 3/100
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return value;
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}
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int yylex() {
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if (*inp == '\0') return YYEOF;
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// Skip all whitespace.
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while (*inp == ' ' || *inp == '\t') { inp++; }
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// Assign & consume current character.
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int c = *inp++;
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// Check for NUM.
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if (isdigit(c)) {
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yylval.fval = acc_float(c); // Set the token value.
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return NUM;
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}
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switch (c) {
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case '+': return PLUS;
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case '\n': return NL;
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case '-': return NEG;
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case '*': return MULT;
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default: return CALL;
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}
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fprintf(stderr, "Unexpected character: %c\n", c);
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return 0;
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}
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void yyerror(char const* s) { fprintf(stderr, "Parse error: %s\n", s); }
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