https://github.com/maxgekk/mur
mur is an interpreter and editor for simple MapReduce language
https://github.com/maxgekk/mur
Last synced: 3 months ago
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mur is an interpreter and editor for simple MapReduce language
- Host: GitHub
- URL: https://github.com/maxgekk/mur
- Owner: MaxGekk
- License: bsd-2-clause
- Created: 2017-05-11T18:28:46.000Z (about 8 years ago)
- Default Branch: master
- Last Pushed: 2017-05-29T20:53:39.000Z (about 8 years ago)
- Last Synced: 2025-01-19T08:28:24.454Z (5 months ago)
- Language: Scala
- Size: 117 KB
- Stars: 0
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# MuR
MuR is an interpreter and editor for simple MapReduce language. MuR is just acronym for Map Und Reduce.
The language has the following grammar:
```
expr ::= expr op expr | (expr) | identifier | { expr, expr } | number |
map(expr, identifier -> expr) | reduce(expr, expr, identifier identifier -> expr)
op ::= + | - | * | / | ^
stmt ::= var identifier = expr | out expr | print "string"
program ::= stmt | program stmt
```
## Editor
The following command creates jar file with MuR Editor:
```
$ sbt assembly
[info] Packaging /Users/dev/proj/mur/target/scala-2.12/mur-editor.jar ...
```
To run the editor:
```
java -jar /Users/dev/proj/mur/target/scala-2.12/mur-editor.jar
```
## Tests
Run the tests with enabled coverage:
```
$ sbt clean coverage test
```
To enable/disable coverage directly in build, change this:
```
coverageEnabled := false
```
To generate the coverage reports run
```
$ sbt coverageReport
```
It creates the file with reports: target/scala-2.12/scoverage-report/index.htm
## Example
Parsing and interpretation of the example:
```
var n = 500
var sequence = map({0, n}, i -> (-1)^i / (2 * i + 1))
var pi = 4 * reduce(sequence, 0, x y -> x + y)
print "pi = "
out pi
```
just launch:
```
$ sbt "run-main mur.Main"
[info] Running mur.Main
pi = 3.143588659585789
[success] Total time: 1 s, completed May 14, 2017 6:21:27 PM
```
# API
There are two main methods:
- Parsers.parse converts a program text to its intermediate representation (IR). IR is defined in IR.scala and Expr.scala
- Interpreter.run takes an IR and executes it step-by-step, and produces a sequence of strings as a result of the out and print statements