Category:Guish: Difference between revisions
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There are single and double quoting: anything embedded inside single quotes '', is treated literally (no escaping takes place) and as a single token.
Variable
Escaping ("\n\t\r\f\v\b") takes place only inside double quotes "".
<pre> a = 'my string'; puts "this is: @{a}"
puts "sum of 1 + 5 is: @(add(1, 5))"</pre>
Anything embedded inside '''{}''' is treated as a code block and no variable substitution is done at definition time.
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<pre> fn = {return 1 2 3}
puts join(fn())</pre>
== Conditionals ==
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<pre> a = 1
after 4 {a = 0}
while {eq(@a, 1)} {
wait 1 puts 'true'
}
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And here another one using '''each''' function:
<pre> each({puts @1}, 1, 2, 3, 4, 5})</pre>
And another one of a '''for''' loop:
<pre> for x in 1 2 3 4: { puts @x }</pre>
== Tail recursion optimization (TCO) ==
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Anything inside '''[]''' is trated as a slice expression. The usage is '''[<n>[,<x>]]''', when <n> is an index, and <x> is an optional end index (always inclusive); if the preceding argument is a regular token, then the expression will return its characters as specified by index(es), otherwise if it's a block, the expression will return its tokens:
<pre> puts {1, 2, 3, 4, {a, b}, cat}[4][1]</pre>
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; '''self'''
: variable holding the window id when in signal code.
; '''args'''
: refers to the block in which there are positional arguments and function arguments (alternative syntax).
; '''FILE'''
: variable holding the path of current source file.
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; '''c'''
: A checkbox.
; '''t'''
: A label with a totally transparent background (requires a compositor).
= SPECIAL COMMANDS =
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; '''=> <signal> <subcmd>'''
: register a sub-command <subcmd> to run when <signal> triggers. For normal signals (eg. signals tied to elements), there must exist an implied subject.
; '''
: unregister a sub-command <subcmd> previously registered on signal <signal>.
; '''q'''
: quit guish (exit status 0).
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: quit guish (exit status <status>).
; '''cd <path>'''
: change
; '''run <cmd>'''
: execute shell command <cmd>.
; '''
:
; '''
:
; '''
:
; '''
: unsets a variable (<name>) or timed scheduled procedure registered with <num>, see '''every''' command. If, instead of <name|num>, an element id <wid> is given and a name attribute <attr> is given, deletes that element attribute.
; '''source <file>'''
: execute commands from file.
; '''vars [<wid>]'''
: shows all variables present in the current scope or, if <wid> element id is given, shows all element attributes (uses stderr).
; '''ls'''
: display all existing widgets
; '''del <wid>'''
: delete a widget with id <wid>.
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: schedule <block> to run once after <seconds> seconds are elapsed.
; '''wait <seconds>'''
: stop command execution and wait <seconds> seconds before resuming
; '''if <condition> <block>'''
: executes <block> if condition evaluates to true (see Conditionals).
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; '''until <condition> <block>'''
: executes <block> until <condition> evaluates to true (see Conditionals).
; '''for [<
: executes the block <
; '''break'''
: exit from current loop.
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; ''': <title>'''
: set element title.
; '''s <text>'''
: set element style (see STYLE AND ATTRIBUTES section).
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; '''m <x> <y>'''
: move element to coords <x> <y>.
; '''/ [<l|L|a|A|p|x|n> [<...>]]'''
: draws/fills lines, points and arcs depending on operation (See Drawing operations subsection). Origin coordinates correspond to the bottom-left corner as default Cartesian axes (instead of upper-left one used for windows/elements). If no operation is given, then all drawings are discarded from the implied element.
; '''A <element> <alignment>'''
: moves implied element to <element> using <alignment> (see alignment in STYLE AND ATTRIBUTES section, as <alignment> opts are similar).
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; '''Y'''
: enable/disable (toggle) moving an element inside its parent by click-and-drag on y axis Enabling this will automatically exclude the flag to click-and-drag and move parent.
== Drawing operations ==
; '''l [<color> <x1> <y1> <x2> <y2> [<...>]]'''
: draws lines between given points using color <color> (beware this command consumes all the phrase). If no arguments are given, then all element lines are discarded.
; '''L [<color> <x1> <y1> <x2> <y2> [<...>]]'''
: fills the polygon described by given points using color <color> (beware this command consumes all the phrase). If no arguments are given, then all filled polygons are discarded.
; '''a [<color> <x> <y> <w> <h> <alpha> <beta> [<...>]]'''
: draws an arc using color <color> and whose "center" is at <x> <y>, major and minor axes are respectively <w> and <h>, start and stop angles are <alpha> and <beta> (consumes all the phrase). If no arguments are given, then all element arcs are discarded.
; '''A [<color> <x> <y> <w> <h> <alpha> <beta> [<...>]]'''
: fills an arc using color <color> and whose "center" is at <x> <y>, major and minor axes are respectively <w> and <h>, start and stop angles are <alpha> and <beta> (consumes all the phrase). If no arguments are given, then all element arcs are discarded.
; '''p [<color> [<...>]]'''
: draws given points using color <color> (beware this command consumes all the phrase). If no arguments are given, then all points are discarded.
; '''x [<color> [<...>]]'''
: draws given pixels using color <color> (beware this command consumes all the phrase). If no arguments are given, then all pixels are discarded.
; '''n [<color> <name> <x> <y>]'''
: draws given point using color <color> and putting the text <name> at that point. If no arguments are given, then all points are discarded.
= NORMAL COMMANDS =
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Every phrase is reduced to an empty phrase while evaluating:
<pre> a
This example is composed by 2 phrases, and the code block in each phrase is executed before each assignment.
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<pre> |b||b||b|+
== Variable substitution ==
With the '''=''' operator (actually, it's a special statement command), it's possible to assign
<pre> b = 123; puts @a</pre>
There are two methods to define/create empty variables: by explicitely assing an empty string to a variable (ex. a = "") or by simply omit the value (ex. a =).
In addition, if there is more than one value to assign, a block is automatically created (embedding those values) and assigned to that variable:
<pre> a = 1 # this simply assigns '1' to the variable 'a'
b = 1, 2, 3, 4 # this instead assigns the block '{1, 2, 3, 4}' to the variable 'a'
c = {1, 2, 3, 4} # same but explicit</pre>
Each block has it's own scope, and variable resolution works by searching from the last scope to the first. Ex:
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name = 'random name'
puts "@{gname} is maybe @{name}"</pre>
== Element
Anything inside '''||''' is an element expression; a widget of a given element is created and its X11 window id substituted. The synopsis is: |<element>[{<width>, <height>}]| Ex.
<pre> |b|+</pre>
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xterm program is spawn, and can be driven (almost) like a normal element.
= OPERATORS =
== Binary ==
; '''<s> .. <e>'''
: returns integers starting at <s> and ending at <e> (inclusive) as multiple tokens.
; '''<var> = [<val>, [<val1>, ...]]'''
: defines a variable (consumes all the phrase). If no value is given, an empty token is assigned to the variable. If a single value is given, that value is assigned to the variable. If multiple values are given, then all these values are wrapped inside a block, and this block is assigned to the variable.
; '''<attr> .= [<val>, [<val1>, ...]]'''
: defines an element using the implied subject attribute (consumes all the phrase). If no value is given, an empty token is assigned to the variable. If a single value is given, that value is assigned to the variable. If multiple values are given, then all these values are wrapped inside a block, and this block is assigned to the variable.
== Unary ==
; '''@<varname|num>'''
: dereferences a variable name (or positional argument).
; '''@*'''
: returns all function parameters as tokens (usable with command line parameters too).
; '''[<eid>].<attr>'''
: dereferences an element attribute; if <eid> is given, uses that element, otherwise uses implied subject.
= ELEMENT ATTRIBUTES =
Every element can have some default readonly attributes and a variable number of custom attributes (which can be set by using assignment only, not by using '''let''' function). To set an attribute, use the "'''.='''" operator; to get it instead use the "'''.'''" operator.
<pre> b = |b|; myattr .= 'here'; puts(@b.myattr)</pre>
In the last example, a custom attribute, "myattr" is created and used.
The following are default attributes (readonly):
; '''t'''
: widget's type.
; '''w
: widget's width.
; '''h
: widget's height.
; '''x
: widget's x coord.
; '''y
: widget's y coord.
; '''b
: widget's border width.
; '''g
: widget's margin width.
; '''d
: widget's text data.
; '''
: widget's title.
; '''c
: widget's checked/unchecked status (only for checkbox).
; '''n
: widget's number of subwidgets (only for page).
; '''s
: widget's subwidgets ids (one token each, only for page).
; '''pid
: process ID associated with the widget.
; '''v
: widget is visible.
; '''e
: widget is enabled (freezed/unfreezed).
; '''f
: widget is focused.
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Symbol "'''...'''" means a variable number of arguments.
; '''exists(<eid>)'''
: returns 1 if a widget with id <eid> exists, 0 otherwise.
; '''read([<file>])'''
: reads and returns a line (excluding newline) from standard input; if an existing
; '''write(<text>, <file>)'''
: writes text into file and returns the number of characters written. Creates the file if it doesn't exist yet.
; '''append(<text>, <file>)'''
: append text to the end of file and returns the number of characters written. Creates the file if it doesn't exist yet.
; '''eval(
: evaluates code by first stringifying all given arguments and then returns the result of evaluation if any. Beware that this function runs in the "current" scope, and can modify it.
; '''
: gets the name of a
; '''each(<function>, ...)'''
: executes <function> for each additional argument given passing it as the first argument to the block. If return values are present, they will be accumulated and then returned.
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; '''if(<cond>, [<v1>, [<v2>]])'''
: if <cond> is true and <v1> is given, returns <v1>, else if <cond> is false and <v2> is given, returns <v2>.
; '''unless(<cond>, [<v1>, [<v2>]])'''
: if <cond> is false and <v1> is given, returns <v1>, else if <cond> is true and <v2> is given, returns <v2>.
; '''and(...)'''
: returns the first true argument; if there are no true arguments, returns the last one which is false. The function evaluates any block given.
; '''or(...)'''
: returns the last true argument if all arguments are true, otherwise returns the first false argument. The function evaluates any block given.
; '''flat(...)'''
: returns all given arguments; if a block is found, then it is flatted.
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; '''popb()'''
: pops the first argument from function arguments (works with command line parameters too). This function is somewhat special, as if there are no arguments to pop.
; '''times(<n>, <arg>)'''
: returns a sequence of tokens made by <n> times <arg>. This function is somewhat special, as when there are 0 tokens to replicate, it'll return nothing (statement behaviour).
; '''get(<name>)'''
: returns the value of the variable with name <name>, or an empty token if the variable
; '''true(<arg>)'''
: returns 1 if <arg> is true, 0 otherwise.
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; '''join(...)'''
: joins blocks and/or tokens by applying the following rules to all arguments given, and accumulates the result as the first operand. If the operands are blocks, then a single new block is created by joining them; if the operands are tokens, then a single new token is created by joining them, and its type will be that of the "second" token; if the operands are mixed (eg. a block and a token), then the token will be embedded inside the block.
; '''isdef(<token>)'''
: returns 1 if <token> is a variable, 0 otherwise.
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; '''seq(<t1>, <t2>, ...)'''
: returns 1 if all arguments are equal (string comparison), 0 otherwise.
; '''add(...)'''
: perform addition.
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; '''mod(...)'''
: perform modulus.
; '''rand()'''
: returns a random positive integer.
; '''sqrt(<n>)'''
: returns the square root of <n>.
; '''cbrt(<n>)'''
: returns the cube root of <n>.
; '''pow(<n>, <e>)'''
: returns the power of <n> raised to <e>.
; '''log(<n>)'''
: returns the base 10 logarithm of <n>.
; '''ln(<n>)'''
: returns the natural logarithm of <n>.
; '''sin(<n>)'''
: returns the sine of <n> (degrees).
; '''cos(<n>)'''
: returns the cosine of <n> (degrees).
; '''tan(<n>)'''
: returns the tangent of <n> (degrees).
; '''hex(<n>)'''
: returns <n> in its hexadecimal representation.
; '''int(<n>)'''
: returns integral part of given number <n>; rounds to nearest integer.
; '''xor(<n1>, <n2>, ...)'''
: perform bitwise XOR.
; '''
: perform bitwise AND.
; '''
: perform bitwise OR.
; '''lsh(<n1>, <n2>, ...)'''
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Each field must be separated by newlines, ''';''' or '''|'''. Colors can be specified by using a common shortname, such as "yellow", or by using RGB value, such as "#ff32ae".
; '''background | bg: <color|/<path to image>>'''
: set background color or a background image by specifying image path; if the string "null" is given as <path to image>, current image is removed. (Background image loading requires building guish with Imlib2 support.)
; '''color | foreground | fg: <color>'''
: set foreground color
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; '''border-color | bc: <color>'''
: set border color
; '''width | w: <value in pixels>'''
: set width
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; '''border | b: <value in pixels>'''
: set border width
; '''line | l: <value in pixels>'''
: set line width (use with "/" command)
; '''margin | g: <value in pixels>'''
: set margin width
| |||