ratio

commit 474200046322ff9e4591e30137ab3eb09dfb8d36
Author: William Casarin <jb55@jb55.com>
Date:   Fri, 29 Sep 2017 20:19:55 -0700

initial commit

Diffstat:
A
.gitignore
 | 
4
++++
A
Makefile
 | 
16
++++++++++++++++
A
lexer.l
 | 
32
++++++++++++++++++++++++++++++++
A
parser.y
 | 
63
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
ratio.h
 | 
7
+++++++

5 files changed, 122 insertions(+), 0 deletions(-)
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,4 @@
+*.o
+*.tab.*
+/lex.yy.c
+/ratio
diff --git a/Makefile b/Makefile
@@ -0,0 +1,16 @@
+
+GEN=parser.tab.c parser.tab.h lex.yy.c
+
+all: ratio
+
+parser.tab.c parser.tab.h:	parser.y
+	bison -d parser.y
+
+lex.yy.c: lexer.l parser.tab.h
+	flex lexer.l
+
+ratio: $(GEN)
+	$(CC) -o $@ -lgmp parser.tab.c lex.yy.c
+
+clean:
+	rm -f $(GEN)
diff --git a/lexer.l b/lexer.l
@@ -0,0 +1,32 @@
+%option noyywrap
+
+%{
+#include <stdio.h>
+#include <gmp.h>
+#include "ratio.h"
+
+#define YY_DECL int yylex()
+
+#include "parser.tab.h"
+
+%}
+
+%%
+
+[ \t]	; // ignore all whitespace
+[0-9]+		{
+  mpz_t i; mpz_init(i);
+  mpq_init(yylval.rval);
+  mpz_set_str(i, yytext, 10);
+  mpq_set_z(yylval.rval, i);
+  return T_RATIO;
+}
+\n		    {return T_NEWLINE;}
+"+"		    {return T_PLUS;}
+"-"		    {return T_MINUS;}
+"*"		    {return T_MULTIPLY;}
+"/"		    {return T_DIVIDE;}
+"("		    {return T_LEFT;}
+")"		    {return T_RIGHT;}
+
+%%
diff --git a/parser.y b/parser.y
@@ -0,0 +1,63 @@
+%{
+
+#include <stdio.h>
+#include <gmp.h>
+#include <stdlib.h>
+
+extern int yylex();
+extern int yyparse();
+extern FILE* yyin;
+
+char buffer[255];
+
+void yyerror(const char* s);
+%}
+
+%union {
+	mpq_t rval;
+}
+
+%token<rval> T_RATIO
+%token T_PLUS T_MINUS T_MULTIPLY T_DIVIDE T_LEFT T_RIGHT
+%token T_NEWLINE T_QUIT
+%left T_PLUS T_MINUS
+%left T_MULTIPLY T_DIVIDE
+
+%type<rval> expr
+
+%start calc
+
+%%
+
+calc:
+    | calc line
+;
+
+line: T_NEWLINE
+    | expr T_NEWLINE      { mpq_out_str(stdout, 10, $1); printf("\n"); }
+;
+
+expr: T_RATIO				        { mpq_set($$, $1); }
+    | expr T_PLUS expr	    { mpq_add($$, $1, $3); }
+    | expr T_MINUS expr	    { mpq_sub($$, $1, $3); }
+    | expr T_MULTIPLY expr	{ mpq_mul($$, $1, $3); }
+    | expr T_DIVIDE expr	  { mpq_div($$, $1, $3); }
+    | T_LEFT expr T_RIGHT		{ mpq_set($$, $2); }
+;
+
+%%
+
+int main() {
+	yyin = stdin;
+
+	do {
+		yyparse();
+	} while(!feof(yyin));
+
+	return 0;
+}
+
+void yyerror(const char* s) {
+	fprintf(stderr, "Parse error: %s\n", s);
+	exit(1);
+}
diff --git a/ratio.h b/ratio.h
@@ -0,0 +1,7 @@
+#include <gmp.h>
+
+void fresh_ratio(mpq_t r);
+void fresh_bigint(mpz_t i);
+
+void note_mpq(const mpq_t a);
+void note_mpz(const mpz_t a);