added integers, floats, strings, and identifiers

Readme.org

@@ -1,6 +1,6 @@
 * Pinky
 
-Pinky is a little toy programming language, designed to teach about compilers
+[[https://pinky-lang.org/][Pinky]] is a little toy programming language, designed to teach about compilers
 and interpreters development.
 
 In this repository, you'll find the implementation for both an interpreter and

src/lexer.c

@@ -6,6 +6,8 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include <ctype.h>
+
 /* helper functions */
 char
 advance (struct lexer *l)
@@ -85,6 +87,66 @@ add_token (enum token_type type, struct lexer *l)
 	free (lexeme);
 }
 
+void
+handle_number (struct lexer *l)
+{
+	if (!l)
+		return;
+
+	while (isdigit (peek (l)))
+		advance (l);
+
+	if (peek (l) == '.' && isdigit (lookahead (1, l)))
+		{
+			/* if it's a float, consume the second part of the number */
+			do
+				{
+					advance (l);
+				}
+			while (isdigit (peek (l)));
+
+			add_token (TOK_FLOAT, l);
+			return;
+		}
+
+	add_token (TOK_INTEGER, l);
+}
+
+void
+handle_string (char quote, struct lexer *l)
+{
+	if (!l)
+		return;
+
+	while (peek (l) != quote && l->cur < buffer_length (l->source))
+		advance (l);
+
+	if (l->cur >= buffer_length (l->source))
+		{
+			/* we reached the end of the file without closing the string */
+			fprintf (stderr,
+							 "lexer.c: handle_string - unterminated string on line %d\n",
+							 l->line);
+			exit (EXIT_FAILURE);
+		}
+
+	advance (l); /* consume the closing quote */
+
+	add_token (TOK_STRING, l);
+}
+
+void
+handle_identifier (struct lexer *l)
+{
+	if (!l)
+		return;
+
+	while (isalnum (peek (l)) || peek (l) == '_')
+		advance (l);
+
+	add_token (TOK_IDENTIFIER, l);
+}
+
 /* public functions */
 struct lexer
 lexer_create ()
@@ -167,9 +229,12 @@ lexer_lex (struct lexer *l)
 				add_token (match ('=', l) ? TOK_GE : TOK_GT, l);
 			else if (c == ':')
 				add_token (match ('=', l) ? TOK_ASSIGN : TOK_COLON, l);
-			/* check if it's a number, and determine if it's a float or integer */
-			/* check if it's a " or ', and get the string */
-			/* check if it's an alpha character or _, then handle identifiers */
+			else if (isdigit (c))
+				handle_number (l);
+			else if (c == '\'' || c == '"')
+				handle_string (c, l);
+			else if (isalpha (c) || c == '_')
+				handle_identifier (l);
 		}
 }
 

tests/program.pinky

@@ -0,0 +1,10 @@
+# initialise variables
+pi := 3.141592
+
+x := 8.23
+
+if x >= 0 then
+	println ("x is positive")
+else
+	println ("x is negative")
+end