83 lines
5.3 KiB
Markdown
83 lines
5.3 KiB
Markdown
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## Syntax and Special Forms
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|Special Form|Argument Evaluations|Purpose|
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|`(if cond a b)`|`if` only evaluates its `cond` argument. If `cond` is truthy (non-zero), then `a` is evaluated. Otherwise, `b` is evaluated.|This special form is the main method of control flow.|
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|`(do a b c ...)`|`do` takes a list of s-expressions and evaluates them in the order they were given (in the current scope), and then returns the result of the last s-expression.|This special form allows lambda functions to have multi-step bodies.|
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|`(scope a b c ...)`|`scope` takes a list of s-expressions and evaluates them in the order they were given _in a new scope_, and then returns the result of the last s-expression.|This special form allows the user to evaluate blocks of code in new scopes.|
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|`(defun name params body)`|`defun` evaluates none of its arguments.|This special form allows the user to conveniently define functions.|
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|`(define name value)`|`define` evaluates the `value` argument, which is then assigned to `name` in the current scope.|This special form allows the user to bind atoms to values in a scope.|
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|`(lambda params body)`|`lambda` evaluates none of its arguments.|This special form allows the user to define anonymous functions.|
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|`(quote x)`|`quote` evaluates none of its arguments.|This is equivalent to the `'expr` syntactic sugar.|
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|`(for x list ...)`|`for` evaluates only its list argument.|`for` iterates through the list storing each element in `x`, and then evaluating all of the rest of the values in the `for` body. It then returns the last value evaluated.|
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|`(while cond ...)`|`while` evaluates only its cond argument.|`while` evaluates its condition expression every iteration before running. If it is true, it continues to evaluate every expression in the `while` body. It then returns the last value evaluated.|
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## Library
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|Signature|Description|Return values|
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|`(= a b)`|Test whether two values are equal|`1` when equal otherwise `0`|
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|`(!= a b)`|Test whether two values are not equal|`1` when not equal otherwise `0`|
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|`(> a b)`|Test whether one value is greater to another |`1` when greater otherwise `0`|
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|`(< a b)`|Test whether one value is less to another |`1` when less otherwise `0`|
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|`(>= a b)`|Test whether one value is greater or equal to another |`1` when greater or equal otherwise `0`|
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|`(<= a b)`|Test whether one value is less or equal to another |`1` when less or equal otherwise `0`|
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|`(+ a b ..)`|Sum multiple values |sum of values|
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|`(- a b)`|Substract two values |result of substraction|
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|`(* a b ..)`|Multiply several values|result of multiplication|
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|`(/ a b)`|Divide two values|result of division|
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|`(% a b)`|Remainder of division|result of operation|
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|`(list ..)`|Create a list of values||
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|`(insert list index element)`|Insert an element into a list. Indexed from 0|new list with value inserted|
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|`(index list index)`|Return element at index in list|Element at index|
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|`(remove list index)`|Remove a value at an index from a list|List with element removed|
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|`(len list)`|Get the length of a list|list length|
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|`(push list element)`|Add an item to the end of a list|new list with element added|
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|`(pop list)`|Returns last element of list|Last element|
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|`(head list)`|Returns first element of a list|First element|
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|`(tail list)`|Return all elements of list except first one|List without first element|
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|`(first list)`|Returns first element of a list|First element|
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|`(last list)`|Returns last element of list|Last element|
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|`(range low high)`|Returns list with elements in range low .. high|`(range 1 5) => (1 2 3 4)`|
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|`(member list item)`|Returns true (1) when list contains item||
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|`(uniq list)`|Returns list with removed duplicates ||
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|`(make-list len)`|Return list with len nil elements|`(make-list 3) => (nil nil nil)`|
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|`(make-list-of len value)`|Return list with len value elements||
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|`(map ..)`||`(map (lambda (x) (+ x 10)) '(1 2 3 4 5 6)) => (11 12 13 14 15 16)`|
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|`(filter lambda list)`||`(filter (lambda (x) (> x 2)) '(1 2 3 4 5)) => (3 4 5)`|
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|`(reduce lambda acumulator list)`||`>>> (reduce (lambda (x y) (+ (* x 10) y)) 0 '(1 2 3 4)) => 1234`|
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|`(exit code)`|Exit the program with an integer code||
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|`(quit code)`|Same as (exit ..)||
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|`(print ..)`|Print several values and return the last one||
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|`(input [prompt])`|Get user input with an optional prompt||
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|`(random low high)`|Get a random number between two numbers inclusively||
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|`(include file)`|Read a file and execute its code||
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|`(read-file filename)`|Get the contents of a file||
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|`(write-file filename)`|Write a string to a file||
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|`(read-url url [headers])`|Reads URL|Returnd list (status_code content)|
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|`(system-cmd command_str)`|Execute system command||
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|`(ls-dir ..)`|List a dir|List of directory entries|
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|`(is-file? ..)`|Returns true if passed filename is a file||
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|`(is-dir? ..)`|Returns true if passed filename is a directory||
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|`(parse-csv string)`|Parse CSV string||
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|`(parse-json json_string)`|Parse JSON string||
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|`(save-csv ..)`|||
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|`(get-universal-time)`|Get current time as secs from epoch||
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|`(date-to-str ..)`|||
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|`(str-to-date ..)`|||
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|`(date-add ..)`|||
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|`(debug ..)`|||
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|`(display ..)`|||
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|`(replace ..)`|||
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|`(regex-search? ..)`|||
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|`(string-pad str len char rpad_lpad)`|||
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|`(int ..)`|||
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|`(float ..)`|||
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|`(eval ..)`|||
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|`(type ..)`|||
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|`(parse ..)`|||
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|`(make-list size)`|||
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|`(make-list-of size value)`|||
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|`(xx ..)`|||
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