4i: Parsing (Useful Idioms)
+alf
+alfAlphabetic characters
Parse alphabetic characters, both upper and lowercase.
Source
++ alf ;~(pose low hig)Examples
> (scan "a" alf)
'a'
> (scan "A" alf)
'A'
> `tape`(scan "AaBbCc" (star alf))
"AaBbCc"+aln
+alnAlphanumeric characters
Parse alphanumeric characters - both alphabetic characters and numbers.
Source
++ aln ;~(pose low hig nud)Examples
> (scan "0" aln)
'0'
> `tape`(scan "alf42" (star aln))
"alf42"+alp
+alpAlphanumeric and -
Parse alphanumeric strings and hep, "-".
Source
++ alp ;~(pose low hig nud hep)Examples
> (scan "7" alp)
'7'
> (scan "s" alp)
's'
> `tape`(scan "123abc-" (star alp))
"123abc-"+bet
+betAxis syntax -, +
Parse the hep and lus axis syntax.
Source
++ bet ;~(pose (cold 2 hep) (cold 3 lus))Examples
> (scan "-" bet)
2
> (scan "+" bet)
3+bin
+binBinary to atom
Parse a tape of binary (0s and 1s) and produce its atomic representation.
Source
++ bin (bass 2 (most gon but))Examples
> (scan "0000" bin)
0
> (scan "0001" bin)
1
> (scan "0010" bin)
2
> (scan "100000001111" bin)
2.063+but
+butBinary digit
Parse a single binary digit.
Source
++ but (cook |=(a=@ (sub a '0')) (shim '0' '1'))Examples
> (scan "0" but)
0
> (scan "1" but)
1
> (scan "01" but)
! {1 2}
! 'syntax-error'
! exit
> (scan "01" (star but))
~[0 1]+cit
+citOctal digit
Parse a single octal digit.
Source
++ cit (cook |=(a=@ (sub a '0')) (shim '0' '7'))Examples
> (scan "1" cit)
1
> (scan "7" cit)
7
> (scan "8" cit)
! {1 1}
! 'syntax-error'
! exit
> (scan "60" (star cit))
~[6 0]+dem
+demDecimal to atom
Parse a decimal number to an atom.
Source
++ dem (bass 10 (most gon dit))Examples
> (scan "7" dem)
7
> (scan "42" dem)
42
> (scan "150000000" dem)
150.000.000
> (scan "12456" dem)
12.456+dit
+ditDecimal digit
Parse a single decimal digit.
Source
++ dit (cook |=(a=@ (sub a '0')) (shim '0' '9'))Examples
> (scan "7" dit)
7
> (scan "42" (star dit))
~[4 2]
> (scan "26000" (star dit))
~[2 6 0 0 0]+dog
+dog. optional gap
Dot followed by an optional gap, used with numbers.
Source
++ dog ;~(plug dot gay)Examples
> (scan "." dog)
['.' ~]
> (scan "a. " ;~(pfix alf dog))
['.' ~]+dof
+dof- optional gap
Hep followed by an optional gap, used with @p & @q syntax.
Source
++ dof ;~(plug hep gay)Examples
> (scan "-" dof)
['-' ~]
> (scan "- " dof)
['-' ~]+doh
+doh@p separator
Phonetic base phrase separator
Source
++ doh ;~(plug ;~(plug hep hep) gay)Examples
> (scan "--" doh)
[['-' '-'] ~]
> (scan "-- " doh)
[['-' '-'] ~]+dun
+dun-- to ~
Parse phep, --, to null, ~.
Source
++ dun (cold ~ ;~(plug hep hep))Examples
> (scan "--" dun)
~+duz
+duz== to ~
Parse stet, ==, to null ~.
Source
++ duz (cold ~ ;~(plug tis tis))Examples
> (scan "==" duz)
~+gah
+gahNewline or ' '
Whitespace component, either newline or space.
Source
++ gah (mask [`@`10 ' ' ~])Examples
> `tape`(scan " \0a \0a" (star gah))
" \0a \0a"+gap
+gapPlural whitespace
Separates tall runes
Source
++ gap (cold ~ ;~(plug gaq (star ;~(pose vul gah))))Examples
> `tape`(scan " \0a \0a" gap)
""
> (scan "\0a \0a XYZ" ;~(pfix gap (jest 'XYZ')))
'XYZ'+gaq
+gaqEnd of line
Two spaces, a newline, or comment.
Source
++ gaq ;~ pose
(just `@`10)
;~(plug gah ;~(pose gah vul))
vul
==Examples
> (scan "123\0a" ;~(sfix dem gaq))
123
> (scan "123 :: foo\0a" ;~(sfix dem gaq))
123+gaw
+gawClassic whitespace
Terran whitespace.
Source
++ gaw (cold ~ (star ;~(pose vul gah)))Examples
> (scan " \0a :: foo \0a" gaw)
~
> (scan " " gaw)
~
> (scan "\0a" gaw)
~+gay
+gayOptional gap
Optional gap.
Source
++ gay ;~(pose gap (easy ~))Examples
> (scan " " gay)
~
> (scan " " gay)
~
> (scan "\0a" gay)
~
> (scan "" gay)
~+gon
+gonLong numbers
Parse long numbers - Numbers which wrap around the shell with the line
Source
++ gon ;~(pose ;~(plug bas gay fas) (easy ~))Examples
> 'abc\
/def'
'abcdef'
> (scan "\\\0a/" gon)
['\\' ~ '/']+gul
+gulAxis syntax < or >
Parse the axis gal and gar axis syntax.
Source
++ gul ;~(pose (cold 2 gal) (cold 3 gar))Examples
> (scan "<" gul)
2
> (scan ">" gul)
3+hex
+hexHex to atom
Parse any hexadecimal number to an atom.
Source
++ hex (bass 16 (most gon hit))Examples
> (scan "a" hex)
10
> (scan "A" hex)
10
> (scan "2A" hex)
42
> (scan "1ee7" hex)
7.911
> (scan "1EE7" hex)
7.911
> (scan "1EE7F7" hex)
2.025.463
> `@ux`(scan "1EE7F7" hex)
0x1e.e7f7+hig
+higUppercase
Parse a single uppercase letter.
Source
++ hig (shim 'A' 'Z')Examples
> (scan "G" hig)
'G'
> (scan "ABCDEFGHIJKLMNOPQRSTUVWXYZ" (star hig))
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"+hit
+hitHex digits
Parse a single hexadecimal digit.
Source
++ hit ;~ pose
dit
(cook |=(a=char (sub a 87)) (shim 'a' 'f'))
(cook |=(a=char (sub a 55)) (shim 'A' 'F'))
==Examples
> (scan "a" hit)
10
> (scan "A" hit)
10
> (scan "2A" (star hit))
~[2 10]+iny
+inyIndentation block
Apply +rule to indented block starting at current column number, omitting the leading whitespace.
Accepts
sef is a +rule
Produces
A +rule.
Source
++ iny
|* sef=rule
|= nail ^+ (sef)
=+ [har tap]=[p q]:+<
=+ lev=(fil 3 (dec q.har) ' ')
=+ eol=(just `@t`10)
=+ =- roq=((star ;~(pose prn ;~(sfix eol (jest lev)) -)) har tap)
;~(simu ;~(plug eol eol) eol)
?~ q.roq roq
=+ vex=(sef har(q 1) p.u.q.roq)
=+ fur=p.vex(q (add (dec q.har) q.p.vex))
?~ q.vex vex(p fur)
=- vex(p fur, u.q -)
:+ &3.vex
&4.vex(q.p (add (dec q.har) q.p.&4.vex))
=+ res=|4.vex
|- ?~ res |4.roq
?. =(10 -.res) [-.res $(res +.res)]
(welp [`@t`10 (trip lev)] $(res +.res))Examples
> `tape`(scan " foo\0a bar" ;~(pfix ace ace ace (iny (star ;~(pose prn (just '\0a'))))))
"foo\0abar"Discussion
Note the amount of indentation whitespace to be stripped from the beginning of each line is determined by the value of .q (the column) in the $hair when +iny is first called. This means something like the +pfix expression in the example above is necessary to set the level of indentation. Additionally, the +rule given to +iny must consume the whole line including the line ending.
+low
+lowLowercase
Parse a single lowercase letter.
Source
++ low (shim 'a' 'z')Examples
> (scan "g" low)
'g'+mes
+mesHexbyte
Parse a hexbyte.
Source
++ mes %+ cook
|=({a/@ b/@} (add (mul 16 a) b))
;~(plug hit hit)Examples
> (scan "2A" mes)
42
> (scan "42" mes)
66+nix
+nixLetters and underscore
Parse Letters and _.
Source
++ nix (boss 256 (star ;~(pose aln cab)))Examples
> `@t`(scan "as_me" nix)
'as_me'+nud
+nudNumeric
Parse a numeric character - A number.
Source
++ nud (shim '0' '9')Examples
> (scan "0" nud)
'0'
> (scan "7" nud)
'7'+prn
+prnPrintable character
Parse any printable character.
Source
++ prn ;~(less (just `@`127) (shim 32 256))Examples
> (scan "h" prn)
'h'
> (scan "!" prn)
'!'
> (scan "\01" prn)
! {1 1}
! exit+qat
+qatChars in blockcord
Parse a single character contained in a multi-line cord block.
Source
++ qat ;~ pose
prn
;~(less ;~(plug (just `@`10) soz) (just `@`10))
==Examples
> ^- tape
%+ scan
"'''\0aabc\0adef\0aghi\0a'''"
%+ ifix
:- ;~(plug soz (just `@`10))
;~(plug (just `@`10) soz)
(star qat)
"abc\0adef\0aghi"+qit
+qitChars in cord
Parse an individual character to its cord atom representation. Escaped characters are converted to the value they represent.
Source
++ qit ;~ pose :: chars in a cord
;~(less bas soq prn)
;~(pfix bas ;~(pose bas soq mes)) :: escape chars
==Examples
> (scan "%" qit)
'%'
> `tape`(scan "cord" (star qit))
"cord"
> `tape`(scan "\\0a" (star qit))
"\0a"+qut
+qutCord
Parse single-soq cord with \{gap}/ anywhere in the middle, or triple-single quote (aka triple-soq) cord, between which must be in an indented block.
Source
++ qut ;~ simu soq
;~ pose
;~ less soz
(ifix [soq soq] (boss 256 (more gon qit)))
==
=+ hed=;~(pose ;~(plug (plus ace) vul) (just '\0a'))
%- iny %+ ifix
:- ;~(plug soz hed)
;~(plug (just '\0a') soz)
(boss 256 (star qat))
==
==Examples
> `@t`(scan "'cord'" qut)
'cord'
> `@t`(scan "'''\0aabc\0adef\0a'''" qut)
'abc\0adef'+soz
+sozDelimiting '''
Parse a triple-single quote, used for multiline strings.
Source
++ soz ;~(plug soq soq soq)Examples
> (scan "'''" soz)
['\'' '\'' '\'']+sym
+symTerm
A term: a lowercase letter, followed by letters, numbers, or -.
Source
++ sym
%+ cook
|=(a=tape (rap 3 ^-((list @) a)))
;~(plug low (star ;~(pose nud low hep)))Examples
> `term`(scan "sam-2" sym)
%sam-2+mixed-case-symbol
+mixed-case-symbolMixed-case term
The same as +sym but allowing uppercase letters.
Source
++ mixed-case-symbol
%+ cook
|=(a=tape (rap 3 ^-((list @) a)))
;~(plug alf (star alp))Examples
> `term`(scan "sAm-2" mixed-case-symbol)
%sAm-2+ven
+ven+>- axis syntax
Axis syntax parser
Source
++ ven ;~ (comp |=([a=@ b=@] (peg a b)))
bet
=+ hom=`?`|
|= tub=nail
^- (like @)
=+ vex=?:(hom (bet tub) (gul tub))
?~ q.vex
[p.tub [~ 1 tub]]
=+ wag=$(p.tub p.vex, hom !hom, tub q.u.q.vex)
?> ?=(^ q.wag)
[p.wag [~ (peg p.u.q.vex p.u.q.wag) q.u.q.wag]]
==Examples
> (scan "->+" ven)
11
> (scan "->+<-" ven)
44+vit
+vitBase64 digit
Parse a standard base64 digit.
Source
++ vit
;~ pose
(cook |=(a=@ (sub a 65)) (shim 'A' 'Z'))
(cook |=(a=@ (sub a 71)) (shim 'a' 'z'))
(cook |=(a=@ (add a 4)) (shim '0' '9'))
(cold 62 (just '-'))
(cold 63 (just '+'))
==Examples
> (scan "C" vit)
2
> (scan "c" vit)
28
> (scan "2" vit)
54
> (scan "-" vit)
62+vul
+vulComments to null
Parse comments and produce a null. Note that a comment must be ended with a newline character.
Source
++ vul %+ cold ~
;~ plug col col
(star prn)
(just `@`10)
==Examples
> (scan "::this is a comment \0a" vul)
~
> (scan "::this is a comment " vul)
! {1 21}
! exitLast updated