deep in the forth mines with hacked together forth, in a hacked together virtual machine, running in a hacked together web-based forth IDE.
the next video approaches
the next video approaches
June 27, 2025 at 5:57 PM
deep in the forth mines with hacked together forth, in a hacked together virtual machine, running in a hacked together web-based forth IDE.
the next video approaches
the next video approaches
can't believe i missed this vintage shot of 80s Alfred Aho for the last video... would have been so perfect!
February 17, 2025 at 1:33 PM
can't believe i missed this vintage shot of 80s Alfred Aho for the last video... would have been so perfect!
every day i get up, i make another clone of ed the Standard Unix Text Editor, i do my burpees, and then i study Unix v7's ed.c to figure out how on earth it works.
feels like leetcode for trying to get a job at Bell Labs in 1975
feels like leetcode for trying to get a job at Bell Labs in 1975
January 29, 2025 at 8:25 PM
every day i get up, i make another clone of ed the Standard Unix Text Editor, i do my burpees, and then i study Unix v7's ed.c to figure out how on earth it works.
feels like leetcode for trying to get a job at Bell Labs in 1975
feels like leetcode for trying to get a job at Bell Labs in 1975
when the usenet thread is about to get good
January 18, 2025 at 8:15 PM
when the usenet thread is about to get good
this seems to me VERY sneaky. the append operation for this data structure is mostly O(1), but will occasionally be O(n). but! if you graph out the average operations for n appends to a list, it looks like this
January 15, 2025 at 12:41 AM
this seems to me VERY sneaky. the append operation for this data structure is mostly O(1), but will occasionally be O(n). but! if you graph out the average operations for n appends to a list, it looks like this
and then if you try to add an element that won't fit... it secretly creates another array 2-3x the size and copies all of your elements over
January 15, 2025 at 12:41 AM
and then if you try to add an element that won't fit... it secretly creates another array 2-3x the size and copies all of your elements over
the problem is — accessing elements means scanning the list until you find the item you want. this is O(n), where the array was O(1). a little worrying for a general purpose data structure everyone is using all of the time (and which people will probably embed in other loops)
January 15, 2025 at 12:41 AM
the problem is — accessing elements means scanning the list until you find the item you want. this is O(n), where the array was O(1). a little worrying for a general purpose data structure everyone is using all of the time (and which people will probably embed in other loops)
you can then play with the links to prepend, append, insert, splice, reverse, or most anything you like — all with quite good performance
January 15, 2025 at 12:41 AM
you can then play with the links to prepend, append, insert, splice, reverse, or most anything you like — all with quite good performance
the classic answer to this inflexibility is a data structure called a linked list, in which you store pairs of a value and a link to the next record
January 15, 2025 at 12:41 AM
the classic answer to this inflexibility is a data structure called a linked list, in which you store pairs of a value and a link to the next record
the snag is that you need to know the element size and array length up front. element size you can get around using pointers, but array length is harder. if your array is hard up against other important data, you can't extend it.
January 15, 2025 at 12:41 AM
the snag is that you need to know the element size and array length up front. element size you can get around using pointers, but array length is harder. if your array is hard up against other important data, you can't extend it.
the ability to calculate the location of each item, rather than having to search for it, makes arrays very fast for access and storage. and so long as you know every size up front you can use it to store surprisingly complex types too, like 2d arrays or even trees
January 15, 2025 at 12:41 AM
the ability to calculate the location of each item, rather than having to search for it, makes arrays very fast for access and storage. and so long as you know every size up front you can use it to store surprisingly complex types too, like 2d arrays or even trees
in some ways the 'perfect' list is an array.
you take a fixed number of elements of a fixed size and store them one after the other in memory. to access an element you take the start address and add the element size multiplied by the index
you take a fixed number of elements of a fixed size and store them one after the other in memory. to access an element you take the start address and add the element size multiplied by the index
January 15, 2025 at 12:41 AM
in some ways the 'perfect' list is an array.
you take a fixed number of elements of a fixed size and store them one after the other in memory. to access an element you take the start address and add the element size multiplied by the index
you take a fixed number of elements of a fixed size and store them one after the other in memory. to access an element you take the start address and add the element size multiplied by the index
new video! this datatype → [1, 2, 3] ← is a bit of a marvel. it can store items of any size, grow to any length, rarely causes performance issues, and almost every modern language has one. what is it, really? and how does it work?
January 15, 2025 at 12:41 AM
new video! this datatype → [1, 2, 3] ← is a bit of a marvel. it can store items of any size, grow to any length, rarely causes performance issues, and almost every modern language has one. what is it, really? and how does it work?
yes i have created my own virtual machine with its own assembly language to implement my own linked lists for the next video
January 5, 2025 at 6:37 PM
yes i have created my own virtual machine with its own assembly language to implement my own linked lists for the next video