initial

lisp.c

@@ -0,0 +1,114 @@
+#include <ctype.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+
+#define NOB_IMPLEMENTATION
+#include "nob.h"
+
+typedef enum e_Token_Kind {
+    TOKEN_KIND_PAR_LEFT,
+    TOKEN_KIND_PAR_RIGHT,
+    TOKEN_KIND_NUMBER,
+    TOKEN_KIND_SYMBOL,
+} TokenKind;
+
+typedef struct s_Token {
+    TokenKind kind;
+    Nob_String_View data;
+} Token;
+
+typedef struct s_Tokens {
+    Token *items;
+    size_t count;
+    size_t capacity;
+} Tokens;
+
+void tokenize(Nob_String_View content, Tokens *tokens) {
+    for (size_t i = 0; i < content.count; i++) {
+        char c = content.data[i];
+
+        int kind = -1;
+        switch (c) {
+        case '(': {
+            kind = TOKEN_KIND_PAR_LEFT;
+        } break;
+        case ')': {
+            kind = TOKEN_KIND_PAR_RIGHT;
+        } break;
+        }
+
+        if (kind != -1) {
+            Token tok = (Token){.kind = kind, .data = {0}};
+            nob_da_append(tokens, tok);
+            continue;
+        }
+
+        Nob_String_Builder sb = {0};
+        while (isdigit(c)) {
+            nob_sb_appendf(&sb, "%c", c);
+            c = content.data[++i];
+        }
+
+        if (sb.count > 0) {
+            i--;
+
+            Token tok =
+                (Token){.kind = TOKEN_KIND_NUMBER, .data = nob_sb_to_sv(sb)};
+            nob_da_append(tokens, tok);
+            continue;
+        }
+
+        // symbols shouldn't start with a digit
+        bool condition =
+            isascii(c) && !isdigit(c) && !isblank(c) && c != '(' && c != ')';
+        while (condition) {
+            nob_sb_appendf(&sb, "%c", c);
+            c = content.data[++i];
+            condition = isascii(c) && !isblank(c) && c != '(' && c != ')';
+        }
+
+        if (sb.count > 0) {
+            i--;
+
+            Token tok =
+                (Token){.kind = TOKEN_KIND_SYMBOL, .data = nob_sb_to_sv(sb)};
+            nob_da_append(tokens, tok);
+        }
+    }
+}
+
+const char *token_kind_name(TokenKind kind) {
+    switch (kind) {
+    case TOKEN_KIND_PAR_LEFT:
+        return "PAR_LEFT";
+    case TOKEN_KIND_PAR_RIGHT:
+        return "PAR_RIGHT";
+    case TOKEN_KIND_NUMBER:
+        return "NUMBER";
+    case TOKEN_KIND_SYMBOL:
+        return "SYMBOL";
+    default:
+        UNREACHABLE("Unknown token type");
+    }
+}
+
+int main(int argc, char **argv) {
+    if (argc < 2)
+        return 1;
+
+    argv++;
+    const char *line = *argv++;
+    Nob_String_View view = nob_sv_from_cstr(line);
+
+    Tokens tokens = {0};
+    tokenize(view, &tokens);
+
+    for (size_t i = 0; i < tokens.count; i++) {
+        Token tok = tokens.items[i];
+        printf("Token(kind=%s, data=" SV_Fmt ")\n", token_kind_name(tok.kind),
+               SV_Arg(tok.data));
+    }
+
+    return 0;
+}