frontend: lexer: Create identifier token for names

Signed-off-by: Ian Moffett <ian@mirocom.org>

frontend/lexer.c

@@ -10,12 +10,14 @@
 
 #include <sys/types.h>
 #include <stddef.h>
+#include <stdlib.h>
 #include <stdbool.h>
 #include <unistd.h>
 #include <errno.h>
 #include <ctype.h>
 #include "frontend/token.h"
 #include "frontend/lexer.h"
+#include "common/ptrbox.h"
 
 /*
  * Test if a given character counts as a whitespace character
@@ -142,6 +144,61 @@ lexer_consume(struct quip_state *state, bool skip_ws)
     return '\0';
 }
 
+/*
+ * Scan a name and create a token if valid
+ *
+ * @state:  Quip state
+ * @lc:     Last character
+ * @tokres: Token result written here
+ *
+ * Returns zero on success
+ */
+static int
+lexer_scan_name(struct quip_state *state, int lc, struct token *tokres)
+{
+    char c, *buf;
+    size_t bufsz, bufcap;
+
+    if (state == NULL || tokres == NULL) {
+        return -1;
+    }
+
+    if (!isalpha(lc) && lc != '_') {
+        return -1;
+    }
+
+    bufsz = 0;
+    bufcap = 8;
+    if ((buf = malloc(bufcap)) == NULL) {
+        return -1;
+    }
+
+    buf[bufsz++] = lc;
+    for (;;) {
+        c = lexer_consume(state, false);
+        if (!isalnum(c) && c != '_') {
+            buf[bufsz] = '\0';
+            lexer_putback(state, c);
+            break;
+        }
+
+        buf[bufsz++] = c;
+        if (bufsz >= bufcap - 1) {
+            bufcap += 8;
+            buf = realloc(buf, bufcap);
+        }
+
+        if (buf == NULL) {
+            return -1;
+        }
+    }
+
+    tokres->type = TT_NAME;
+    tokres->s = ptrbox_strdup(&state->ptrbox, buf);
+    free(buf);
+    return 0;
+}
+
 int
 lexer_scan(struct quip_state *state, struct token *tokres)
 {
@@ -170,6 +227,12 @@ lexer_scan(struct quip_state *state, struct token *tokres)
         lexer_putback(state, c);
         tokres->type = TT_COLON;
         return 0;
+    default:
+        if (lexer_scan_name(state, c, tokres) == 0) {
+            return 0;
+        }
+
+        break;
     }
 
     return -1;

include/frontend/token.h

@@ -31,6 +31,7 @@ struct token {
     tt_t type;
     union {
         char c;
+        char *s;
     };
 };