Web-Projects/blog-static
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Fix list rendering in some posts.

Browse Source
This commit is contained in:
Danila Fedorin 2019-08-16 03:29:13 -07:00
parent 352ec468f7
commit 091a686070
2 changed files with 6 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
content/blog/coq_palindrome.md
View File

@ -7,10 +7,12 @@ Going through the Software Foundations textbook, I found an exercise which I rea
### The inductive definition ### The inductive definition
I wasn’t sure at first why the problem said that the inductive definition should have three constructors. I came up with two ways to construct a palindrome: I wasn’t sure at first why the problem said that the inductive definition should have three constructors. I came up with two ways to construct a palindrome:
* An empty list is a palindrome. * An empty list is a palindrome.
* Adding the same value to the back and the front of another palindrome makes a longer palindrome. * Adding the same value to the back and the front of another palindrome makes a longer palindrome.
Of course, my definition led to only having palindromes of even length. In order to allow for palindromes of odd length, one more rule is needed (another base case): Of course, my definition led to only having palindromes of even length. In order to allow for palindromes of odd length, one more rule is needed (another base case):
* A list with a single value is a palindrome. * A list with a single value is a palindrome.
This translates readily into Coq: This translates readily into Coq:
@ -42,6 +44,7 @@ The proof in the other direction took me a significant amount of time. It was cl
#### A different kind of induction #### A different kind of induction
Coq’s basic induction wouldn’t do. But structural induction doesn’t limit us to a particular definition of a list; it just states that if: Coq’s basic induction wouldn’t do. But structural induction doesn’t limit us to a particular definition of a list; it just states that if:
* We can prove that a proposition holds for the primitive values of a type * We can prove that a proposition holds for the primitive values of a type
* We can prove that if the proposition holds for the building blocks of a value of the type then the proposition holds for the value built of those blocks * We can prove that if the proposition holds for the building blocks of a value of the type then the proposition holds for the value built of those blocks

4
content/blog/crystal_on_arm.md
View File

@ -33,6 +33,7 @@ git checkout 0.27.2
``` ```
Now, I had the compiler and the source. I was ready to compile the source to get myself a nice ARM Crystal compiler. But how? The official guide specified two options for cross compilation: Now, I had the compiler and the source. I was ready to compile the source to get myself a nice ARM Crystal compiler. But how? The official guide specified two options for cross compilation:
* `--cross-compile` - This option is basically a flag. You just add it to the command to enable cross compilation. * `--cross-compile` - This option is basically a flag. You just add it to the command to enable cross compilation.
* `--target=<llvm target triple>` - This specifies the target architecture you're building for. * `--target=<llvm target triple>` - This specifies the target architecture you're building for.
@ -43,9 +44,10 @@ gcc -dumpmachine
This produced the output `armv7l-unknown-linux-gnueabihf`. This was exactly what I needed to know! This produced the output `armv7l-unknown-linux-gnueabihf`. This was exactly what I needed to know!
Finally, looking through the Makefile in the repository, I found three more flags that are used by default in the process: Finally, looking through the Makefile in the repository, I found three more flags that are used by default in the process:
* `-D without_openssl` * `-D without_openssl`
* `-D without_zlib` * `-D without_zlib`
* `--release` - for faster compiler * `--release` - for a faster compiler
To compile the compiler, I had to compile the `src/compiler/crystal.cr` file. With all these options, the command came out to be: To compile the compiler, I had to compile the `src/compiler/crystal.cr` file. With all these options, the command came out to be:
``` ```