fix dip

6 files changed, 70 insertions, 7 deletions

diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..d8da1e4
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "doxygen-awesome-css"]
+	path = doxygen-awesome-css
+	url = https://github.com/jothepro/doxygen-awesome-css.git
diff --git a/Doxyfile b/Doxyfile
index ab9c0dc..fba1270 100644
--- a/Doxyfile
+++ b/Doxyfile
@@ -949,7 +949,7 @@ WARN_LOGFILE           =
 # spaces. See also FILE_PATTERNS and EXTENSION_MAPPING
 # Note: If this tag is empty the current directory is searched.
 
-INPUT                  = include/ src/
+INPUT                  = include/ src/ MAINPAGE.md
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses
@@ -1365,7 +1365,7 @@ HTML_STYLESHEET        =
 # documentation.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
-HTML_EXTRA_STYLESHEET  =
+HTML_EXTRA_STYLESHEET  = doxygen-awesome-css/doxygen-awesome.css
 
 # The HTML_EXTRA_FILES tag can be used to specify one or more extra images or
 # other source files which should be copied to the HTML output directory. Note
@@ -1388,7 +1388,7 @@ HTML_EXTRA_FILES       =
 # The default value is: AUTO_LIGHT.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
-HTML_COLORSTYLE        = AUTO_LIGHT
+HTML_COLORSTYLE        = LIGHT
 
 # The HTML_COLORSTYLE_HUE tag controls the color of the HTML output. Doxygen
 # will adjust the colors in the style sheet and background images according to
@@ -1716,7 +1716,7 @@ DISABLE_INDEX          = NO
 # The default value is: NO.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
-GENERATE_TREEVIEW      = NO
+GENERATE_TREEVIEW      = YES
 
 # When both GENERATE_TREEVIEW and DISABLE_INDEX are set to YES, then the
 # FULL_SIDEBAR option determines if the side bar is limited to only the treeview
diff --git a/MAINPAGE.md b/MAINPAGE.md
index de5bdce..0ba8c25 100644
--- a/MAINPAGE.md
+++ b/MAINPAGE.md
@@ -1,3 +1,44 @@
-# Introduction
+# Introduction {#mainpage}
 Stem aims to be a minimal interpreted stack based programming language
-that allows for metaprogramming and a foreign language interface.
+that allows for metaprogramming and a foreign language interface. It features
+a C API that is elegant and simple. Additionally, garbage collection is
+not needed in this language as the responsibility of writing memory safe
+operations is put in the hands of the maintainers of the builtin functions
+and FLI library maintainers. Therefore, the end user does not need to worry
+about memory allocation while the implementation remains extremely simple.
+
+# Installation
+`make` and `sudo make install`. To generate the html documentation, one must first
+install `doxygen` as an optional dependency. If you are on a BSD or MacOS, you
+must use `gmake`.
+
+# Quickstart
+Because this is a stack based language, all operations are done in reverse polish. For example, to add two numbers together:
+```
+3 4 +
+```
+would return the result `7`. `3` and `4` get pushed onto the stack when they are written out as literals in the language, and `+` is a builtin
+that adds the top two elements of the stack. In this language, there are two kinds of objects: literals
+(strings, ints, floats, words, and literals of type `VERROR` are built in), and quotes that contain these literals (arrays of valid statements that can be evaluated).
+Words might be new to you if you're coming from another language. If you're coming from lisp, a words are analogous to symbols. If you're coming from another
+language, a word is a literal that has the special property that they can be bound to functions. For example, the `+` symbol is a word, which is bound
+to the action of adding two numbers when called.
+
+Let's look at a real example of a REPL implementation in this language:
+```
+repl [ "> " . read strquote eval repl ] func
+repl
+```
+`repl` is a word, which means it is a literal, and everything that is a literal gets pushed onto the stack.
+Everything between the `[` and `]` is an element in a quote. Then, we see the `func` word. If a word is already bound to a function,
+the function gets called instead of getting pushed to the stack, so the `func` function gets called, which takes the top two
+elements off the stack, and creates a function called `repl` where now every time `repl` is called in the future, the quote is evaluated
+instead.
+
+Let's take a closer look at the quote:
+```
+"> " . read strquote eval repl
+```
+`.` takes the first thing off the stack and prints it. In this case, it would print a prompt `> ` every REPL loop. `read` reads a value from stdin,
+then `strquote` turns that string into a quote. `eval` pops the first thing off the stack and evaluates the quote in the same way calling a function
+does, and then finally `repl` gets called again at the end so we can loop forever.
diff --git a/doxygen-awesome-css b/doxygen-awesome-css
new file mode 160000
+Subproject df88fe4fdd97714fadfd3ef17de0b4401f80405
diff --git a/examples/fib.stem b/examples/fib.stem
new file mode 100644
index 0000000..4104a36
--- /dev/null
+++ b/examples/fib.stem
@@ -0,0 +1,19 @@
+fib [
+  dup 1 <= [ ] [
+    dup 1 - fib
+    swap
+    dup 2 - fib
+    swap
+    dsc
+    +
+  ] if
+] func
+
+main [
+  dup 10 <= [
+    dup fib .
+    1 + main
+  ] [ exit ] if
+] func
+
+0 main
diff --git a/src/builtins.c b/src/builtins.c
index f801028..31981c3 100644
--- a/src/builtins.c
+++ b/src/builtins.c
@@ -548,7 +548,7 @@ void dip(value_t *v) {
       eval(value_copy(v2->quote->items[i]));
     }
     value_free(array_pop(EVAL_STACK));
-    value_free(array_pop(EVAL_STACK));
+    array_pop(EVAL_STACK);
   } else {
     eval(v1);
   }