From 226bfe84c5f690462adbf386dc66316cc21fdb28 Mon Sep 17 00:00:00 2001
From: crupest <crupest@outlook.com>
Date: Mon, 22 Nov 2021 20:53:01 +0800
Subject: import(life): Add compile principle codes.

---
 works/life/compile-principle-experiment/1/hoc.y    | 65 ++++++++++++++++++++++
 works/life/compile-principle-experiment/1/makefile |  5 ++
 2 files changed, 70 insertions(+)
 create mode 100644 works/life/compile-principle-experiment/1/hoc.y
 create mode 100644 works/life/compile-principle-experiment/1/makefile

(limited to 'works/life/compile-principle-experiment/1')

diff --git a/works/life/compile-principle-experiment/1/hoc.y b/works/life/compile-principle-experiment/1/hoc.y
new file mode 100644
index 0000000..c4452ad
--- /dev/null
+++ b/works/life/compile-principle-experiment/1/hoc.y
@@ -0,0 +1,65 @@
+%{
+#define  YYSTYPE  double   /* data type of yacc stack */
+#include <stdio.h>
+#include <ctype.h>
+#include <math.h>
+
+int yylex();
+int yyerror(const char * s);
+%}
+%token  NUMBER
+%left  '+' '-'    /* left associative, same precedence */
+%left  '*' '/' '%'   /* left assoc., higher precedence */
+%left	UNARYMINUS
+%%
+list:    /* nothing */
+  | list '\n'
+  | list expr '\n'    { printf("%lf\n", $2); }
+  ;
+expr:    NUMBER  { $$ = $1; }
+  | expr '+' expr  { $$ = $1 + $3; }
+  | expr '-' expr  { $$ = $1 - $3; }
+  | expr '*' expr  { $$ = $1 * $3; }
+  | expr '/' expr  { $$ = $1 / $3; }
+  | expr '%' expr  { $$ = fmod($1, $3); }
+	| '-' expr  %prec UNARYMINUS { $$ = -$2; }
+  | '(' expr ')'  { $$ = $2; }
+  ;
+%%
+  
+int lineno = 1;
+
+int main(int argc, char** argv)
+{
+  yyparse();
+  return 0;
+}
+
+int yylex()
+{
+  int c;
+
+  do {
+    c = getchar();
+  } while (c == ' ' || c == '\t');
+
+  if (c == EOF)
+    return 0;
+
+  if (c == '.' || isdigit(c)) {
+    ungetc(c, stdin);
+    scanf("%lf", &yylval);
+    return NUMBER;
+  }
+
+  if (c == '\n')
+    lineno++;
+
+  return c;
+}
+
+int yyerror(const char* s)
+{
+  fprintf(stderr, "Error occured near line %d\n", lineno);
+  return 0;
+}
diff --git a/works/life/compile-principle-experiment/1/makefile b/works/life/compile-principle-experiment/1/makefile
new file mode 100644
index 0000000..65bcca2
--- /dev/null
+++ b/works/life/compile-principle-experiment/1/makefile
@@ -0,0 +1,5 @@
+hoc:	hoc.c
+	cc hoc.c -o hoc
+
+hoc.c:	hoc.y
+	bison hoc.y -o hoc.c
-- 
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