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Update red.html.markdown

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Some of the code lines were too long to fit the box so I shortened these and made a few changes in the text so it looks better at the points where the extra lines were added.
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iArnold 2014-02-07 20:34:08 +01:00
parent 8d82b55947
commit bcd930047d
1 changed files with 22 additions and 15 deletions
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red.html.markdown
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@ -23,14 +23,17 @@ from any platform to any other platform. And it will do this all from a binary e
Ready to learn your first Red?
```
All text before the header will be treated as comment, as long as you avoid using the word "red"
starting with a capital "R" in this pre-header text. This is a temporary shortcoming of the used lexer but
most of the time you start your script or program with the header itself.
All text before the header will be treated as comment, as long as you avoid using the
word "red" starting with a capital "R" in this pre-header text. This is a temporary
shortcoming of the used lexer but most of the time you start your script or program
with the header itself.
The header of a red script is the capitalized word "red" followed by a
whitespace character followed by a block of square brackets [].
The block of brackets can be filled with useful information about the script or program: the author,
the filename, the version, the license, what the program does or needs.
The red/System header is just like the red header, only saying "red/System" and not "red".
The block of brackets can be filled with useful information about this script or
program: the author's name, the filename, the version, the license, a summary of
what the program does or any other files it needs.
The red/System header is just like the red header, only saying "red/System" and
not "red".
Red []
@ -98,7 +101,8 @@ my-integer: 0
type? my-integer
integer!
; A variable can be initialized using another variable that gets initialized at the same time.
; A variable can be initialized using another variable that gets initialized
; at the same time.
i2: 1 + i1: 1
; Arithmetic is straightforward
@ -128,8 +132,9 @@ i1 / i2 ; result 0 (0.5, but truncated towards 0)
if a < 0 [print "a is negative"]
; either
; Evaluate a block of code if a given condition is true, else evaluate an alternative block of code.
; If last expressions in both blocks have the same type, EITHER can be used inside an expression.
; Evaluate a block of code if a given condition is true, else evaluate an alternative
; block of code. If the last expressions in both blocks have the same type, EITHER can
; be used inside an expression.
either a < 0 [
either a = 0 [
msg: "zero"
@ -142,7 +147,8 @@ either a < 0 [
print ["a is " msg lf]
; An alternative way to write it (allowed because all code paths return a value of the same type):
; There is an alternative way to write this
; (Which is allowed because all code paths return a value of the same type):
msg: either a < 0 [
either a = 0 [
@ -156,8 +162,8 @@ msg: either a < 0 [
print ["a is " msg lf]
; until
; Loop over a block of code until the condition at end of block, is met. UNTIL does not return any value,
; so cannot be used in an expression.
; Loop over a block of code until the condition at end of block, is met.
; UNTIL does not return any value, so it cannot be used in an expression.
c: 5
until [
prin "o"
@ -166,11 +172,12 @@ until [
]
; will output:
ooooo
; Note that the loop will always be evaluated at least once, even if the condition is not met from the beginning.
; Note that the loop will always be evaluated at least once, even if the condition is
; not met from the beginning.
; while
; While a given condition is met, evaluate a block of code. WHILE does not return any value,
; so cannot be used in an expression.
; While a given condition is met, evaluate a block of code.
; WHILE does not return any value, so it cannot be used in an expression.
c: 5
while [c > 0][
prin "o"