From 92d9da14c2c4b801f3115a481b102c1c528d5e28 Mon Sep 17 00:00:00 2001
From: Jacob Signorovitch <jacob.signorovitch@gmail.com>
Date: Sat, 9 Nov 2024 10:27:03 -0500
Subject: [PATCH] Grammars are broken.

---
 README.md           |  1 -
 src/grammar.y       | 12 +++++++++++-
 src/include/ast.h   |  6 +++---
 src/include/lexer.h |  2 ++
 src/lexer.c         | 38 +++++++++++++++++++-------------------
 src/main.c          | 17 +++++++++++++++--
 6 files changed, 50 insertions(+), 26 deletions(-)

diff --git a/README.md b/README.md
index 827a5d4..17517e4 100644
--- a/README.md
+++ b/README.md
@@ -35,4 +35,3 @@ Variables can be defined, with several attributes:
 > d:lazy = (1 + 1)  // Interpreter will wait as long as possible before
                     // evaluating.
 ```
-
diff --git a/src/grammar.y b/src/grammar.y
index 4025133..35c9db9 100644
--- a/src/grammar.y
+++ b/src/grammar.y
@@ -1,17 +1,27 @@
+%code requires {
+    #include "../../src/include/ast.h"
+}
+
+%{
+#include "../../src/include/ast.h"
+%}
+
 %union {
     int intval;
     char* strval;
+    AST* ast;
 }
 
 %token <intval> NUM
 %token <strval> CALL
 %token PLUS
+%type <ast> exp
 
 %%
 
 exp:
    NUM {}
-   | exp PLUS exp {}
+   | exp PLUS exp { $$ = ast_type_call_init("+", 2, [ast_type_num_init($1), ast_type_num_init(int val)]}
    ;
 
 %%
diff --git a/src/include/ast.h b/src/include/ast.h
index 02789c8..f1051c9 100644
--- a/src/include/ast.h
+++ b/src/include/ast.h
@@ -14,6 +14,9 @@ typedef struct {
     void* data;
 } AST;
 
+AST* ast_init(ASTType type, void* data);
+void ast_destroy(AST* ast);
+
 typedef struct {
     int val;
 } ASTTypeNum;
@@ -30,7 +33,4 @@ typedef struct {
 ASTTypeCall* ast_type_call_init(char* to, size_t argc, AST** argv);
 void ast_type_call_destroy(ASTTypeCall* call);
 
-AST* ast_init(ASTType type, void* data);
-void ast_destroy(AST* ast);
-
 #endif
diff --git a/src/include/lexer.h b/src/include/lexer.h
index 7d5e97b..37c05f8 100644
--- a/src/include/lexer.h
+++ b/src/include/lexer.h
@@ -71,4 +71,6 @@ void lexerstate_print_raw();
 // Create the input string.
 void lexer_set_global(const char* str);
 
+int yylex();
+
 #endif
diff --git a/src/lexer.c b/src/lexer.c
index 0a20f69..14d1eab 100644
--- a/src/lexer.c
+++ b/src/lexer.c
@@ -8,6 +8,10 @@
 #include "include/token.h"
 #include "include/util.h"
 
+#include "../build/grammars/grammar.tab.h"
+
+extern YYSTYPE yylval;
+
 Lexer* thelexer = NULL;
 
 void lexer_init(char* src) {
@@ -138,36 +142,32 @@ void lexerstate_print_raw() {
     } else printf("%s", lexerstate_names[s]);
 }
 
-#include "../build/grammars/grammar.tab.h"
-
-extern YYSTYPE yylval;
-
-int yylex(void) {
+int yylex() {
     if (*thelexer->cchar == '\0') return YYEOF;
 
-    switch (*thelexer->cchar) {
-    case ' ':
-    case '\t': thelexer->cchar++;
-    }
+    // Skip all whitespace.
+    while (*thelexer->cchar == ' ' || *thelexer->cchar == '\t')
+        thelexer->cchar++;
 
     // Assign & consume current character.
     int c = *thelexer->cchar++;
 
+    // Check for NUM.
+    if (isdigit(c)) {
+        int value = c - '0';
+        while (isdigit(*thelexer->cchar)) {
+            value = value * 10 + (*thelexer->cchar - '0'); // Accumulate value.
+            thelexer->cchar++;
+        }
+        yylval.intval = value; // Set the token value.
+        return NUM;
+    }
+
     switch (c) {
     case '+': return PLUS;
     default:  return CALL;
     }
 
-    if (isdigit(c)) {
-        int value = c - '0'; // Start with the first digit
-        while (isdigit(*thelexer->cchar)) {
-            value = value * 10 + (*thelexer->cchar - '0'); // Accumulate value
-            thelexer++;
-        }
-        yylval.intval = value; // Set the token value
-        return NUM;            // Return the INTEGER token type
-    }
-
     fprintf(stderr, "Unexpected character: %c\n", c);
 
     return 0;
diff --git a/src/main.c b/src/main.c
index 8c1a9d2..449436d 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,11 +1,19 @@
 #include <stdio.h>
 
+#include "include/ast.h"
 #include "include/dstr.h"
-#include "include/util.h"
 #include "include/lexer.h"
+#include "include/util.h"
+
+#include "../build/grammars/grammar.tab.h"
+
+// Global Abstract Syntax Tree.
+AST* root = NULL;
+
+extern int yyparse();
 
 int main(int argc, char** argv) {
-    while(1) {
+    while (1) {
         Dstr* cline = dstr_init(); // The current line.
         printf("> ");
         fflush(stdout);
@@ -20,6 +28,11 @@ int main(int argc, char** argv) {
             lexer_init(cline->buf);
             lexer_lex();
             lexer_print();
+            if (yyparse() == 0) {
+                printf("Parsed successfully!\n");
+            } else {
+                printf("Parse error.\n");
+            }
             lexer_destroy();
         }