simple calculator example

1 files changed, 62 insertions, 0 deletions

diff --git a/demos/sample-files/arithmetic-skeleton.c b/demos/sample-files/arithmetic-skeleton.c
new file mode 100644
index 0000000..ef5ec2f
--- /dev/null
+++ b/demos/sample-files/arithmetic-skeleton.c
@@ -0,0 +1,62 @@
+#include <stdio.h>ae
+#include <stdlib.h>
+
+#include "lr-parser.c"
+#include "bin/generated.c"
+
+#include "parts/toklist.h"
+
+enum symbol {
+    PLUS = 0,
+    MINUS,
+    LPAREN,
+    RPAREN,
+    N0, N1,
+    END_INPUT,
+
+    EP, E, T, N,
+    SYMBOLS_END,
+};
+
+struct token {
+    symbol s;
+};
+
+static inline struct token *char_to_token(char c)
+{
+    static struct token t;
+
+    switch(c) {
+    case '+': t = (struct token){PLUS}; break;
+    case '-': t = (struct token){MINUS}; break;
+    case '(': t = (struct token){LPAREN}; break;
+    case ')': t = (struct token){RPAREN}; break;
+    case '0': t = (struct token){N0}; break;
+    case '1': t = (struct token){N1}; break;
+    case  0 : t = (struct token){END_INPUT}; break;
+    default: fprintf(stderr, "ERROR: Unknown character '%c'\n", c); exit(1);
+    }
+
+    return &t;
+}
+
+static char *input;
+
+symbol token_sym(struct token *t) { return t->s; }
+int token_val(struct token *t) { return 0; }
+struct token *toklist_eat() { return char_to_token(*(input++)); } // unsafe
+struct token *toklist_peek() { return char_to_token(*input); }    // unsafe
+
+int main(int argc, char **argv)
+{
+    if(argc != 2) {
+        fprintf(stderr, "ERROR: Not enough arguments\n");
+        return 1;
+    }
+
+    input = argv[1];
+
+    printf("INPUT: '%s'\n", input);
+    printf("OUTPUT: %d\n", lr_parser());
+    return 0;
+}