Memelang is the most token-efficient language for querying structured data, knowledge graphs, and retrieval-augmented generation pipelines. See the Python GitHub repository.
m=100 actor="Mark Hamill" role="Luke Skywalker" movie="Star Wars" rating=4.5;
m=101 actor="Harrison Ford" role="Han Solo" movie="Star Wars" rating=4.6;
m=102 actor="Carrie Fisher" role=Leia movie="Star Wars" rating=4.2;
m=110 actor="Mark Hamill" role=Joker movie="Batman: Mask of the Phantasm" rating=4.7;
m=111 actor="Harrison Ford" role="Indiana Jones" movie="Raiders of the Lost Ark" rating=4.8;
m=112 actor="Carrie Fisher" role=Marie movie="When Harry Met Sally" rating=4.3;
m=200 person="Mark Hamill" birthyear=1951 birthplace="Oakland, CA";
m=201 person="Harrison Ford" birthyear=1942 birthplace="Chicago, IL";
m=202 person="Carrie Fisher" birthyear=1956 birthplace="Burbank, CA";
m=300 place="Oakland, CA" population=433000 climate=Mediterranean foundedyear=1852;
m=301 place="Chicago, IL" population=2740000 climate="Humid Continental" foundedyear=1833;
m=302 place="Burbank, CA" population=105000 climate=Mediterranean foundedyear=1887;
A meme comprises key-value pairs, like a database row
\s+whitespaces separate pairsm=idstarting pair (like a primary key);terminating semicolon
A key-value pair comprises four parts
- Key operator is empty or
!(negates the key name) - Key is empty, alphanumeric string, or comma-separated OR-list (like a database column)
- Value operator must be
=!=><<=or>= - Value is empty, integer, float, alphanumeric string, CSV-style quoted string, or comma-separated OR-list
- No whitespaces between keys/values/operators/commas in one pair
A comment is prefixed with double forward slashes //
Queries are partial memes. Empty parts are wildcards. Each query pair is returned in the result.
- Empty value (
K1=) matches all pairs for that key - Empty key (
=V1) matches all pairs for that value - Empty key and value (
=) matches all pairs in the meme - Comma-separated keys match any listed key
- Comma-separated values match any listed value
- The
!key operator negates all keys in the list - The
!=value operator negates all values in the list
// Query for all movies with Mark Hamill as an actor
actor="Mark Hamill" movie=;
// Query for all relations and values from all memes relating to Mark Hamill:
="Mark Hamill" =;
// Value inequalities
population>100000 place=;
rating>=4.3 rating<=4.7 actor= role=;
// OR lists
K1,K2=V1,V2 // key= (K1 or K2) and value= (V1 or V2)
K1,K2!=V1,V2 // key= (K1 or K2) and value!=(V1 or V2)
!K1,K2=V1,V2 // key!=(K1 or K2) and value= (V1 or V2)
!K1,K2!=V1,V2 // key!=(K1 or K2) and value!=(V1 or V2)
!K1,K2>V1 // key!=(K1 or K2) and value> V1
// Query for (actor OR role) = ("Luke Skywalker" OR "Mark Hamill")
actor,role="Luke Skywalker","Mark Hamill" movie=;
// Query for actors who are not Mark Hamill or Carrie Fisher
actor!="Mark Hamill","Carrie Fisher" role= movie=;
// Query for Mark Hamill for all keys except actor and role
!actor,role="Mark Hamill" movie=;
// Example response
m=100 actor="Mark Hamill" movie="Star Wars";
Distinct items (actors, movies, etc.) usually occupy distinct memes with unique m=id identifiers. Joins match multiple memes. Using K1[K2 joins a first meme to a second meme where the value of K1 equals the value of K2. No spaces between the keys and brackets. No need to close brackets, a semicolon closes all brackets. Only join keys with similar values like actor[actor actor[person not dissimilar values like actor[birthyear role[place.
// Query for all of Mark Hamill's costars
actor="Mark Hamill" movie[movie actor=;
// Query for the actor's birthplace
actor[person birthplace=;
// Query for people born in the year their birthplace was founded
person= birthyear[foundedyear place=;
// Query for the other movies Mark Hamill's costars have acted in
actor="Mark Hamill" movie[movie actor= actor[actor movie=;
// Query for the population of the birthplace of the Star Wars cast
movie="Star Wars" actor[person birthplace[place population=;
Joined queries return combined memes where each pair belongs to the preceding m= meme.
m=100 actor="Mark Hamill" movie="Star Wars" m=101 movie="Star Wars" actor="Harrison Ford";
m=100 actor="Mark Hamill" movie="Star Wars" m=102 movie="Star Wars" actor="Carrie Fisher";
Passing strictly left to right, each query pair pushes its matched key (string) and value (int, float, string) onto the variable stack. Rightward query pairs can back-reference prior matches. Variables cannot be assigned or forward-reference. Variables cannot be inside quotes. Variables stack until a semicolon wipes the stack. Variables almost always back-reference a prior meme in a complex join (below). However, they occasionally back-reference a pair from the current meme.
@vvalue from one pair back@kkey name from one pair back@keyvalue from lastkey=pair- Case-insensitive
- Only stacked when query pair key is single true string (no wild or
!or,)
Appending :n references n pairs back. One pair back is :1 so @v = @v:1.
@v:2value two pairs back@k:3key three pairs back@key:11value ofkey=with 10 interveningkey=pairs
Examples variable values after the given pair.
movie="Star Wars"@kwill be movie@vand@moviewill be Star Wars
movie=@kwill be movie@vand@moviewill be the returned value like Star Wars
="Star Wars"@kwill be the returned key name like movie@vwill be Star Wars@keynot stacked due to non-string key
// These are unusual examples of variable back-references within one meme
// Actor of titular movie role
role= movie=@v actor=;
role= movie=@role actor=;
role= actor= movie=@v:2;
role= actor= movie=@role;
// Variables may be used in comma lists
role= movie=@v,"Star Wars";
// Swap value into key name (very unusual)
K1= @v=V2;
K1= @K1=V2;
// Swap key name into value (very unusual)
=V1 K2=@k;
By default, a query pair stays within the current meme. However, after an m key query pair, the next query pair may match a different meme. Complex joins can be made using the m key and @m value. The @m variable is automatically populated with the current meme's id.
m=@mandm=@m:1stay in current meme (implicit default)m!=@mjoin to a different memem=join to any meme (current or different)
Typically, immediately after an m pair, the following pair back-references the prior meme. In fact, K1[K2 is shorthand for the most common join K1= m!=@m K2=@v:2, where K2's value in the new meme is @v:2 which back-references two pairs to K1's value in prior meme (variable depth is counted after expansion).
The [ and m!=@m join to different memes, so trailing distinct conditionals like actor!=@actor are redundant and unnecessary.
// Query for all of Mark Hamill's costars
actor="Mark Hamill" movie[movie actor=;
actor="Mark Hamill" movie= m!=@m movie=@v:2 actor=;
movie= actor="Mark Hamill" m!=@m movie=@v:3 actor=;
actor="Mark Hamill" movie= m!=@m movie=@movie actor=;
movie= actor="Mark Hamill" m!=@m movie=@movie actor=;
// Query for the actor's birthplace
actor[person birthplace=;
actor= m!=@m person=@v:2 birthplace=;
actor= m!=@m person=@actor birthplace=;
// Query for people born in the year their birthplace was founded
person= birthyear[foundedyear place=;
person= birthyear= m!=@m foundedyear=@v:2 place=;
person= birthyear= m!=@birthyear foundedyear=@birthyear place=;
// Query for the other movies Mark Hamill's costars have acted in
actor="Mark Hamill" movie[movie actor= actor[actor movie=;
actor="Mark Hamill" movie= m!=@m movie=@v:2 actor= m!=@m actor=@v:2 movie=;
actor="Mark Hamill" movie= m!=@m movie=@movie actor= m!=@m actor=@actor movie=;
// Query for the population of the birthplace of the Star Wars cast
movie="Star Wars" actor[person birthplace[place population=;
movie="Star Wars" actor= m!=@m person=@v:2 birthplace= m!=@m place=@v:2 population=;
movie="Star Wars" actor= m!=@m person=@actor birthplace= m!=@m place=@birthplace population=;
// Inequality join: Query for cities older than Burbank and with populations smaller
place="Burbank, CA" foundedyear= population= m!=@m population>@v:2 foundedyear<@v:4 place=;
place="Burbank, CA" foundedyear= population= m!=@m population>@population foundedyear<@foundedyear place=;
These joins are very rare.
In K1[K2, K1 and/or K2 may be empty, joining on any key names.
K1[expands toK1= m!=@m =@v:2[K2expands to= m!=@m K2=@v:2[expands to= m!=@m =@v:2
Brackets need not be closed. However, the optional shorthand ] unjoins so the query may start new joins from an earlier meme. The number of unjoins must be less than number of joins; only unjoin after a join.
m=@m:nunjoins to n-1 memes prior]expands tom=@m:2, unjoins to one meme prior]]expands tom=@m:3, unjoins to two memes prior
// Empty join keys: Query for every meme related to any value related to Mark Hamill
actor="Mark Hamill" [ =;
actor="Mark Hamill" = m!=@m =@v:2 =;
// Query for each actor's birth place, unjoin, query for other roles in that movie
actor[person birthplace= ] movie[movie role=
actor= m!=@m person=@v:2 birthplace= m=@m:2 movie= m!=@m movie=@v:2 role=
actor= m!=@m person=@actor birthplace= m=@m:2 movie= m!=@m movie=@movie role=
(* Memelang v6 *)
memelang ::= { meme } ;
meme ::= term { div+ term } [div] ';' [div] ;
div ::= WS+ | comment ;
term ::= pair | join | unjoin ;
pair ::= [[keyopr] keys] valopr [values] ; (* no spaces between *)
keys ::= key {',' key} (* no spaces between *)
values ::= value {',' value} (* no spaces between *)
keyopr ::= '!' ;
valopr ::= '=' | '!=' | '<' | '>' | '<=' | '>=' ;
join ::= [key] '[' [key] ; (* no spaces between; no need for ']' *)
unjoin ::= ']'+;
key ::= ALNUM+ | var ;
value ::= NUM | ALNUM+ | quoted | var ;
var ::= '@' ALNUM+ [':' DIGIT+] ;
quoted ::= '"' ( CHAR | '""' )* '"' ;
comment ::= '//' CHAR* ('\n' | EOF) ;
DIGIT ::= '0'..'9' ;
ALNUM ::= 'A'..'Z' | 'a'..'z' | DIGIT | '_' ;
NUM ::= ['-'] DIGIT+ ['.' DIGIT+] ;
WS ::= ' ' | '\t' | '\r' | '\n' ;
CHAR ::= ? any Unicode character except '"' or '\n' ? ;- Error
K1 = V1space around value operator - Error
K1=V1=V2cannot chain values - Error
K1=K2=K3=missing spaces between pairs - Error
K1=V1, V2space after comma - Error
K1, K2, K3=V1space after comma - Error
K1[K2=Xerrant value=X - Error
K1=Y[K2errant value=Y - Error
K1=[K2errant equals - Error
K1[K2[K3joins cannot chain
- Warning
K1[ K2- Errant space after bracket
- Likely meant
K1[K2
- Warning
movie= movie=@v- Missing
m=pair in join - Likely meant
movie= m!=@m movie=@v:2
- Missing
- Warning
actor="@v"- Variable inside quotes
- Likely meant
actor=@v
- Warning
movie= m!=@m actor=- Missing variable reference to prior meme
- Likely meant
movie= m!=@m movie=@v:2 actor=
- Warning
movie= m!=@m movie=@v- Wrong variable depth
- Likely meant
movie= m!=@m movie=@v:2
- Warning
movie= m!=@m movie=@v:1- Wrong variable depth
- Likely meant
movie= m!=@m movie=@v:2
- Warning
actor[birthplace- Must join similar values
- Likely meant
actor[person birthplace= - Correct similar joins
actor[actoractor[personbirthyear=@foundedyear - Incorrect dissimilar joins
actor[birthyearactor=@placerating= actor=@v
- Semantic Error
movie= m!=@m actor=@director- Undefined variable
@director - Likely meant
director= movie= m!=@m actor=@director
- Undefined variable
Memelang queries are significantly shorter and clearer than equivalent SQL queries.
actor= role="Luke Skywalker","Han Solo" rating>4;
SELECT actor FROM movies WHERE role IN ('Luke Skywalker', 'Han Solo') AND rating > 4;
person,actor="Mark Hamill","Harrison Ford" movie[movie actor=;
SELECT m1.actor, m1.movie, m2.actor FROM movies m1 JOIN movies m2 ON m1.movie = m2.movie WHERE m1.person IN ('Mark Hamill', 'Harrison Ford') AND m1.actor IN ('Mark Hamill', 'Harrison Ford');
Memelang was created by Bri Holt in a 2023 U.S. Provisional Patent application. ©2025 HOLTWORK LLC. Contact [email protected].