--- /dev/null
+# (c) 2019 Aaron Taylor <ataylor at subgeniuskitty dot com>
+# See LICENSE.txt file for copyright and license details.
+
+include ../config.mk
+
+all: hello
+
+hello:
+ @$(CPP) $(CPP_FLAGS) -o temp.pvvs hello.pvvs
+ @$(VVS_COMPILER) -i temp.pvvs -o hello.vvs
+ @rm -f temp.pvvs
+
+run: hello
+ @$(VVS_INTERPRETER) -i hello.vvs
+
+clean:
+ @rm -f hello.vvs temp.pvvs
--- /dev/null
+# Overview #
+
+This example starts with the `Hello, world!` example from Wikipedia's
+Whitespace page, gradually rewriting it to use the ASCII string feature of the
+VVhitespace compiler and the `printf` subroutine from the stdlib.
+
+# "Hello, World!" in VVhitespace #
+
+Wikipedia's `Hello, World!` example is reproduced below. It follows a simple
+form, pushing an integer corresponding to an ASCII character onto the stack and
+then printing it with an IO instruction, repeating this two part process for
+each character before terminating with the final instruction.
+
+ SSSTSSTSSSN | Push +72 (ASCII H)
+ TNSS | Output character
+ SSSTTSSTSTN | Push +101 (ASCII e)
+ TNSS | Output character
+ SSSTTSTTSSN | Push +108 (ASCII l)
+ TNSS | Output character
+ SSSTTSTTSSN | Push +108 (ASCII l)
+ TNSS | Output character
+ SSSTTSTTTTN | Push +111 (ASCII o)
+ TNSS | Output character
+ SSSTSTTSSN | Push +44 (ASCII ,)
+ TNSS | Output character
+ SSSTSSSSSN | Push +32 (ASCII space)
+ TNSS | Output character
+ SSSTTTSTTTN | Push +119 (ASCII w)
+ TNSS | Output character
+ SSSTTSTTTTN | Push +111 (ASCII o)
+ TNSS | Output character
+ SSSTTTSSTSN | Push +114 (ASCII r)
+ TNSS | Output character
+ SSSTTSTTSSN | Push +108 (ASCII l)
+ TNSS | Output character
+ SSSTTSSTSSN | Push +100 (ASCII d)
+ TNSS | Output character
+ SSSTSSSSTN | Push +33 (ASCII !)
+ TNSS | Output character
+ SSSTSTSN | Push +10 (ASCII '\n')
+ TNSS | Output character
+ NNN | Terminate program
+
+If we push the string onto the stack in reverse order we can rearrange the
+code as shown below. Now we're first pushing all the ASCII characters onto the
+stack, then printing them all at once.
+
+ SSSTSTSN | Push +10 (ASCII '\n')
+ SSSTSSSSTN | Push +33 (ASCII !)
+ SSSTTSSTSSN | Push +100 (ASCII d)
+ SSSTTSTTSSN | Push +108 (ASCII l)
+ SSSTTTSSTSN | Push +114 (ASCII r)
+ SSSTTSTTTTN | Push +111 (ASCII o)
+ SSSTTTSTTTN | Push +119 (ASCII w)
+ SSSTSSSSSN | Push +32 (ASCII space)
+ SSSTSTTSSN | Push +44 (ASCII ,)
+ SSSTTSTTTTN | Push +111 (ASCII o)
+ SSSTTSTTSSN | Push +108 (ASCII l)
+ SSSTTSTTSSN | Push +108 (ASCII l)
+ SSSTTSSTSTN | Push +101 (ASCII e)
+ SSSTSSTSSSN | Push +72 (ASCII H)
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ NNN | Terminate program
+
+As a convenience, the VVhitespace compiler will accept `A""` syntax, generating
+a sequence of `PUSH` instructions, just like the prior examples, that places a
+null-terminated ASCII string on the stack. This allows us to shorten the
+program. Like before, the start of the string is closest to the top of the
+stack. Unlike before, there is now a null terminator at the end of the string.
+For now, we'll just leave that on the stack when the program terminates.
+
+ A"Hello, world!\n"
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ TNSS | Output character
+ NNN | Terminate program
+
+Finally, we will use `printf` from the stdlib to shorten that mass of IO
+instructions. Every stdlib subroutine includes a text description as well as
+diagrams of the call and return stack. From `stdio.pvvs` we see the call stack
+for `printf` reproduced below.
+
+ Call Stack:
+ ACSII '\0'
+ string word n
+ ...
+ string word 1
+ substitution n
+ ...
+ substitution 1
+ number of substitutions <-- TOS
+
+The text description for `printf` also informs us that, if we are printing a
+static string (i.e. no substitutions like '%d'), the `number of substitutions`
+should be `0` and it should be immediately followed by `string word 1`. Looking
+at the call stack, that makes sense since we have no substitutions to place
+between those two things.
+
+Note the ASCII `\0` on the call stack. That corresponds to the null terminator
+at the end of our string that was automatically placed by the `A""` syntax.
+
+Don't forget to `#include` the relevant stdlib files. This is done at the
+bottom of the file since VVhitespace files are executed from top to bottom. You
+wouldn't want to accidentally start executing random library code!
+
+Putting all that together, we discover a greatly simplified program.
+
+ A"Hello, world!\n"
+ SSSSN | PUSH 0 (number of substitutions)
+ NSTTSSSN | JSR > 1000 (stdlib:printf)
+ NNN | Terminate program
+ #include <stdio.pvvs>
+
+This is already saved in `hello.pvvs` which you can execute with `make run`.
--- /dev/null
+@@ This program outputs "Hello, world!"
+
+A"Hello, world!\n"
+SSSSN | ST: PUSH 0
+NSTTSSSN | FC: JSR>1000 (printf; see stdlib)
+NNN | FC: Terminate program
+
+#include <stdio.pvvs>
+++ /dev/null
-# (c) 2019 Aaron Taylor <ataylor at subgeniuskitty dot com>
-# See LICENSE.txt file for copyright and license details.
-
-include ../config.mk
-
-all: hello
-
-hello:
- @$(CPP) $(CPP_FLAGS) -o temp.pvvs hello.pvvs
- @$(VVS_COMPILER) -i temp.pvvs -o hello.vvs
- @rm -f temp.pvvs
-
-run: hello
- @$(VVS_INTERPRETER) -i hello.vvs
-
-clean:
- @rm -f hello.vvs temp.pvvs
+++ /dev/null
-# Overview #
-
-This example starts with the `Hello, world!` example from Wikipedia's
-Whitespace page, gradually rewriting it to use the ASCII string feature of the
-VVhitespace compiler and the `printf` subroutine from the stdlib.
-
-# "Hello, World!" in VVhitespace #
-
-Wikipedia's `Hello, World!` example is reproduced below. It follows a simple
-form, pushing an integer corresponding to an ASCII character onto the stack and
-then printing it with an IO instruction, repeating this two part process for
-each character before terminating with the final instruction.
-
- SSSTSSTSSSN | Push +72 (ASCII H)
- TNSS | Output character
- SSSTTSSTSTN | Push +101 (ASCII e)
- TNSS | Output character
- SSSTTSTTSSN | Push +108 (ASCII l)
- TNSS | Output character
- SSSTTSTTSSN | Push +108 (ASCII l)
- TNSS | Output character
- SSSTTSTTTTN | Push +111 (ASCII o)
- TNSS | Output character
- SSSTSTTSSN | Push +44 (ASCII ,)
- TNSS | Output character
- SSSTSSSSSN | Push +32 (ASCII space)
- TNSS | Output character
- SSSTTTSTTTN | Push +119 (ASCII w)
- TNSS | Output character
- SSSTTSTTTTN | Push +111 (ASCII o)
- TNSS | Output character
- SSSTTTSSTSN | Push +114 (ASCII r)
- TNSS | Output character
- SSSTTSTTSSN | Push +108 (ASCII l)
- TNSS | Output character
- SSSTTSSTSSN | Push +100 (ASCII d)
- TNSS | Output character
- SSSTSSSSTN | Push +33 (ASCII !)
- TNSS | Output character
- SSSTSTSN | Push +10 (ASCII '\n')
- TNSS | Output character
- NNN | Terminate program
-
-If we push the string onto the stack in reverse order we can rearrange the
-code as shown below. Now we're first pushing all the ASCII characters onto the
-stack, then printing them all at once.
-
- SSSTSTSN | Push +10 (ASCII '\n')
- SSSTSSSSTN | Push +33 (ASCII !)
- SSSTTSSTSSN | Push +100 (ASCII d)
- SSSTTSTTSSN | Push +108 (ASCII l)
- SSSTTTSSTSN | Push +114 (ASCII r)
- SSSTTSTTTTN | Push +111 (ASCII o)
- SSSTTTSTTTN | Push +119 (ASCII w)
- SSSTSSSSSN | Push +32 (ASCII space)
- SSSTSTTSSN | Push +44 (ASCII ,)
- SSSTTSTTTTN | Push +111 (ASCII o)
- SSSTTSTTSSN | Push +108 (ASCII l)
- SSSTTSTTSSN | Push +108 (ASCII l)
- SSSTTSSTSTN | Push +101 (ASCII e)
- SSSTSSTSSSN | Push +72 (ASCII H)
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- NNN | Terminate program
-
-As a convenience, the VVhitespace compiler will accept `A""` syntax, generating
-a sequence of `PUSH` instructions, just like the prior examples, that places a
-null-terminated ASCII string on the stack. This allows us to shorten the
-program. Like before, the start of the string is closest to the top of the
-stack. Unlike before, there is now a null terminator at the end of the string.
-For now, we'll just leave that on the stack when the program terminates.
-
- A"Hello, world!\n"
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- TNSS | Output character
- NNN | Terminate program
-
-Finally, we will use `printf` from the stdlib to shorten that mass of IO
-instructions. Every stdlib subroutine includes a text description as well as
-diagrams of the call and return stack. From `stdio.pvvs` we see the call stack
-for `printf` reproduced below.
-
- Call Stack:
- ACSII '\0'
- string word n
- ...
- string word 1
- substitution n
- ...
- substitution 1
- number of substitutions <-- TOS
-
-The text description for `printf` also informs us that, if we are printing a
-static string (i.e. no substitutions like '%d'), the `number of substitutions`
-should be `0` and it should be immediately followed by `string word 1`. Looking
-at the call stack, that makes sense since we have no substitutions to place
-between those two things.
-
-Note the ASCII `\0` on the call stack. That corresponds to the null terminator
-at the end of our string that was automatically placed by the `A""` syntax.
-
-Don't forget to `#include` the relevant stdlib files. This is done at the
-bottom of the file since VVhitespace files are executed from top to bottom. You
-wouldn't want to accidentally start executing random library code!
-
-Putting all that together, we discover a greatly simplified program.
-
- A"Hello, world!\n"
- SSSSN | PUSH 0 (number of substitutions)
- NSTTSSSN | JSR > 1000 (stdlib:printf)
- NNN | Terminate program
- #include <stdio.pvvs>
-
-This is already saved in `hello.pvvs` which you can execute with `make run`.
+++ /dev/null
-@@ This program outputs "Hello, world!"
-
-A"Hello, world!\n"
-SSSSN | ST: PUSH 0
-NSTTSSSN | FC: JSR>1000 (printf; see stdlib)
-NNN | FC: Terminate program
-
-#include <stdio.pvvs>
projects / vvhitespace / commitdiff