first commit

main.cpp

@@ -0,0 +1,52 @@
+#include <stdio.h>
+#include <stdint.h>
+#include "expr.hpp"
+#include "eval.hpp"
+#include "parse.hpp"
+#include "stringify.hpp"
+
+uint32_t read_line(FILE *stream, char *dst, uint32_t max)
+{
+    uint32_t num = 0;
+    for (char c; (c = getc(stream)) != '\n'; )
+        if (num < max) dst[num++] = c;
+    
+    if (max > 0) {
+        if (num == max)
+            num--;
+        dst[num] = '\0';
+    }
+    return num;
+}
+
+int main()
+{
+    for (;;) {
+
+        uint32_t len;
+        char text[1<<9];
+        char pool[1<<12];
+
+        /*
+         * Read an expression from stdin
+         */
+        fprintf(stdout, "> ");
+        len = read_line(stdin, text, sizeof(text));
+
+        /*
+         * Parse it
+         */
+        Expr *e = parse(text, len, pool, sizeof(pool));
+        if (e == nullptr) {
+            fprintf(stderr, "Error\n");
+            continue;
+        }
+
+        /*
+         * Print the expression and its result
+         */
+        stringify(e, text, sizeof(text));
+        fprintf(stdout, "%s = %g\n", text, eval(e));
+    }
+    return 0;
+}