lexer works

.gitignore

@@ -1,3 +1,5 @@
+test.scm
+
 # Created by https://www.gitignore.io/api/c,vim
 # Edit at https://www.gitignore.io/?templates=c,vim
 

comp.c

@@ -0,0 +1,129 @@
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <stdlib.h>
+
+typedef struct __List {
+    void *first;
+    struct List *rest;
+} List;
+
+typedef enum __lextypes {END, INT, ID, OPEN_P, CLOSE_P} lextypes; 
+typedef enum __Bool {False, True} Bool;
+
+typedef struct __Lexeme {
+    lextypes label;
+    char *text;
+} Lexeme;
+
+Bool alpha(char c) {
+    return
+        (c >= 'A' && c <= 'Z') ||
+        (c >= 'a' && c <= 'z') ||
+        c == '_' || c == '+' || c == '-' || c == '*' || c == '/' ;
+}
+Bool numeric(char c) {
+    return c >= '0' && c <= '9';
+}
+Bool alphanumeric(char c) {
+    return alpha(c) || numeric(c);
+}
+
+Lexeme *lexer(char *map, size_t filesize) {
+    Lexeme *lexed = calloc(1, sizeof(Lexeme));
+    Lexeme *current;
+    int len;
+    int count = 1;
+    Bool comment = False;
+    char *end_of_map = map+filesize;
+    for(; map < end_of_map; map++) {
+        if (*map == '\n') {
+            comment = False;
+        } else if (*map == ';') {
+            comment = True;
+        } else if (!comment && *map != ' ' && *map != '\t') {
+            count++;
+            lexed = realloc(lexed, count * sizeof(Lexeme));
+            current = &lexed[count-2];
+            if (*map == '(') {
+                current->label = OPEN_P;
+                current->text = calloc(2, sizeof(char));
+                current->text[0] = '(';
+                current->text[1] = 0;
+            } else if (*map == ')') {
+                current->label = CLOSE_P;
+                current->text = calloc(2, sizeof(char));
+                current->text[0] = ')';
+                current->text[1] = 0;
+            } else if (alpha(*map)) { // first char is alphabetical, its a ID
+                current->label = ID;
+                len = 1;
+                current->text = calloc(1, sizeof(char));
+                for(; alphanumeric(*map); map++) {
+                    len++;
+                    current->text = realloc(current->text, len * sizeof(char));
+                    current->text[len-2] = *map;
+                }
+                current->text[len-1] = 0;
+                map--;
+            } else if (numeric(*map)) { // first char is numerical, its a INT
+                current->label = INT;
+                len = 1;
+                current->text = calloc(1, sizeof(char));
+                for(; numeric(*map); map++) {
+                    len++;
+                    current->text = realloc(current->text, len * sizeof(char));
+                    current->text[len-2] = *map;
+                }
+                current->text[len-1] = 0;
+                map--;
+            } else {
+                fprintf(stderr, "unrecognized char\n");
+                exit(1);
+            }
+        }
+    }
+    lexed[count-1].label = END;
+    lexed[count-1].text = NULL;
+    return lexed;
+}
+
+int main(int argc, char *argv[]) {
+    if (argc != 2) {
+        fprintf(stderr, "too many or too few args\n");
+        exit(1);
+    }
+    int fd = open(argv[1], O_RDONLY);
+    if (fd < 0) {
+        fprintf(stderr, "open syscall error\n");
+        exit(1);
+    }
+    struct stat st;
+    stat(argv[1], &st);
+    size_t filesize = st.st_size;
+
+    char *mapped = (char *) mmap(NULL,
+            filesize, PROT_READ, MAP_PRIVATE, fd, 0);
+
+    Lexeme *lexed = lexer(mapped, filesize);
+
+    munmap(mapped, filesize);
+    close(fd);
+    for (int i = 0; lexed[i].label != END; i++) {
+        if (lexed[i].label == INT) {
+            printf("INT:     %s\n", lexed[i].text);
+        } else if (lexed[i].label == ID) {
+            printf("ID:      %s\n", lexed[i].text);
+        } else if (lexed[i].label == OPEN_P) {
+            printf("OPEN_P:  %s\n", lexed[i].text);
+        } else if (lexed[i].label ==CLOSE_P) {
+            printf("CLOSE_P: %s\n", lexed[i].text);
+        } else {
+            fprintf(stderr, "aaaaaa??\n");
+        }
+    }
+    return 0;
+}

ideas.txt

@@ -0,0 +1,6 @@
+Things I need to implement Scheme at its most basic level:
+	- define
+	- lambda
+	- open (how will filenames/fds be communicated?)
+	- read a byte ( read(fd, void* return value, 1) )
+	- close fd