Be more brief!

1 files changed, 12 insertions, 39 deletions

diff --git a/forth.html.markdown b/forth.html.markdown
index 06c2c6dc..7b805057 100644
--- a/forth.html.markdown
+++ b/forth.html.markdown
@@ -22,13 +22,11 @@ of what is written here should work elsewhere.
 \ It's important to know how forth processes instructions. All programming in Forth is
 \ done by manipulating what's known as the parameter stack (more commonly just referred
 \ to as "the stack"). The stack is a typical last-in-first-out (LIFO) stack. Typing:
-
 5 2 3 56 76 23 65
 
 \ Means 5 gets put on the stack first, then 2, then 3, etc all the way to 65, which
 \ is now at the top of the stack. We can see the length and contents of the stack by
 \ passing forth the word `.s`:
-
 .s <7> 5 2 3 56 76 23 65    \ ok
 
 \ Forth's interpreter interprets what you type in one of two ways: as *words* (i.e. the
@@ -41,20 +39,13 @@ of what is written here should work elsewhere.
 
 \ Lets do a simple equation: adding 5 and 4. In infix notation this would be 5 + 4,
 \ but as forth works in postfix (see above about stack manipulation) we input it like so:
-
 5 4 +    \ ok
 
-\ However, this alone yields "ok", yet no answer. Why? The way forth interprets what
-\ we typed is as such: 5 gets added to the top of the stack, and then 4. Finally,
-\ it runs word `+` on the stack (which pops the top and second value, and adds them),
-\ and inserts the result at the top of the stack. Typing the word `.` will yield
+\ However, this alone yields "ok", yet no answer. Typing the word `.` will yield
 \ the result.
-
 .    \ 9 ok
 
-\ This should illustrate the fundamentals of forth. Lets do a few more arithmetic
-\ tests:
-
+\ This should illustrate how Forth's stack works. Lets do a few more arithmetic tests:
 6 7 * .     \ 42 ok
 1360 23 - . \ 1337 ok
 12 12 / .   \ 1 ok
@@ -84,14 +75,11 @@ over   \ duplicate the second item to the top of the stack
 n roll \ where n is a number, *move* the stack item at that position to the top of the stack
 n pick \ where n is a number, *duplicate* the item at that position to the top of the stack
 
-\ 3rd*: when referring to stack indexes, they are zero-based - i.e. the first element is at
-\ position 0, the second element is at position 1, etc... Just like indexing arrays in
-\ most other languages.
+\ When referring to stack indexes, they are zero-based.
 
 \ ------------------------------ Creating Words ------------------------------
 
 \ Quite often one will want to write their own words.
-
 : square ( n -- n ) dup * ;    \ ok
 
 \ Lets break this down. The `:` word says to Forth to enter "compile" mode. After that,
@@ -102,39 +90,34 @@ n pick \ where n is a number, *duplicate* the item at that position to the top o
 \ switch back into interpret mode.
 
 \ We can check the definition of a word with the `see` word:
-
 see square     \ dup * ; ok
 
 \ ------------------------------ Conditionals ------------------------------
 
 \ Booleans:
 \ In forth, -1 is used to represent truth, and 0 is used to represent false.
-\ The idea behind this is that -1 is 11111111 in binary, whereas 0 is obviously 0 in binary.
+\ The idea is that -1 is 11111111 in binary, whereas 0 is obviously 0 in binary.
 \ However, any non-zero value is usually treated as being true:
 
 42 42 =    / -1 ok
 12 53 =    / 0 ok
 
-\ `if` is a *compile-only word*. This means that it can *only* be used when we're compiling a word.
-\ when creating conditionals, the format is <boolean> `if` <stuff to do> `then` <rest of program>.
+\ `if` is a *compile-only word*. This means that it can only be used when we're compiling a word.
+\ when creating conditionals, the format is `if` <stuff to do> `then` <rest of program>.
 
 : ?>64 ( n -- n ) DUP 64 > if ." Greater than 64!" then ; \ ok
 100 ?>64                                                  \ Greater than 64! ok
 
-\ This unimaginative example displays "Greater than 64!" when the number on the stack is greater
-\ than 64. However, it does nothing when the test is false. Let's fix that with the `else` word!
+\ Else:
 
 : ?>64 ( n -- n ) DUP 64 > if ." Greater than 64!" else ." Less than 64!" then ; \ ok
 100 ?>64                                                                         \ Greater than 64! ok
 20 ?>64                                                                          \ Less than 64! ok
 
-\ As you can see, conditionals behave more or less like they do in most programming languages.
-
 \ ------------------------------ Loops ------------------------------
 
 \ `do` is like `if` in that it is also a compile-only word, though it uses `loop` as its
-\ terminator.
-
+\ terminator:
 : myloop ( -- ) 5 0 do cr ." Hello!" loop ; \ ok
 test
 \ Hello!
@@ -143,31 +126,21 @@ test
 \ Hello!
 \ Hello! ok
 
-\ `do` expects two numbers before it: the end number and the index number, respectively.
-\ (cr means carraige-return, essentially it a newline). This is equivalent to a for-loop
-\ in other languages, with a definite number of times to loop.
-
-\ So what if we want to get the value of the index as we loop? We use `i`.
+\ `do` expects two numbers on the stack: the end number and the index number, respectively.
 
+\ Get the value of the index as we loop with `i`:
 : one-to-15 ( -- ) 15 0 do i . loop ;     \ ok
 one-to-15                                 \ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 ok
 : squares ( -- ) 10 0 do i DUP * . loop ; \ ok
 squares                                   \ 0 1 4 9 16 25 36 49 64 81 ok
 
-\ Thidly, we can also change how large the step is between each loop iteration with `+loop`.
-\ `+loop` reads the number on the top of the stack for how far to move each iteration.
-
+\ Change the "step" with `+loop`:
 : threes ( -- ) 15 0 do i . 3 +loop ; \ ok
 threes                                \ 0 3 6 9 12 ok
 
-\ Finally, while loops:
-
+\ Finally, while loops with `begin` <stuff to do> <flag> `unil`:
 : death ( -- ) begin ." Are we there yet?" 0 until ;
 
-\ Will print "Are we there yet?" forever. While loops are constructed in the format
-\ of `begin` <stuff to do> <flag> `until`. The loop will run until flag is a
-\ truthy value (not 0).
-
 \ ------------------------------ Variables and Memory ------------------------------
 
 \ Sometimes we'll be in a situation where we want more permanent variables: