egison / egison-tutorial

The Egison tutorial

The Egison Tutorial

This is a repository for a tutorial program of Egison. Egison is a pattern-matching-oriented, purely functional programming langauge. Using Egison, we can represent intuitive patterns for non-free data types such as multisets, sets, graphs, and mathematical expressions.

For more information, please visit Egison website.

How to compile and run

% cabal install
% egison-tutorial
Egison Tutorial Version 4.0.0
Welcome to Egison Tutorial!
** Information **
We can use a "Tab" key to complete keywords on the interpreter.
If we type a "Tab" key after a closed parenthesis, the next closed parenthesis will be completed.
*****************
==============================
List of sections in the tutorial.
1: Arithmetic
2: Basics of functional programming
3: Basics of pattern matching
4: Pattern matching for multisets and sets
5: Symbolic computation
6: Differential geometry: tensor analysis
7: Differential geometry: differential forms
==============================
Choose a section to learn.
(1-7): 4
====================
We can describe pattern matching for multisets and sets.
We can change the interpretation of patterns by changing the matcher, the second argument of the matchAll expression).
The meaning of the cons pattern (::) is generalized to divide a collection into "an" element and the rest.

Examples:
  matchAll [1, 2, 3] as list integer with $x :: $xs -> (x, xs)
  matchAll [1, 2, 3] as multiset integer with $x :: $xs -> (x, xs)
  matchAll [1, 2, 3] as set integer with $x :: $xs -> (x, xs)
====================
> matchAll [1, 2, 3] as list integer with $x :: $xs -> (x, xs)
[(1, [2, 3])]

egison-tutorial's Issues

Ambiguous occurrence 'optShowVersion'

Cabal raised error when I was building egison-tutorial-4.0.1 with egison-4.1.0 on haskell:8 docker container:

...
#5 682.3 Failed to build exe:egison-tutorial from egison-tutorial-4.0.1.
#5 682.3 Build log (
#5 682.3 /root/.cabal/logs/ghc-8.10.7/egison-tutorial-4.0.1-e-egison-tutorial-32bbd66ddf7ace983264a8c8fd3aa0a36c7835f7efc41de2c0131eaf79103b5c.log
#5 682.3 ):
#5 682.3 Configuring executable 'egison-tutorial' for egison-tutorial-4.0.1..
#5 682.3 Preprocessing executable 'egison-tutorial' for egison-tutorial-4.0.1..
#5 682.3 Building executable 'egison-tutorial' for egison-tutorial-4.0.1..
#5 682.3 [1 of 2] Compiling Paths_egison_tutorial ( dist/build/egison-tutorial/autogen/Paths_egison_tutorial.hs, dist/build/egison-tutorial/egison-tutorial-tmp/Paths_egison_tutorial.o )
#5 682.3 [2 of 2] Compiling Main             ( Main.hs, dist/build/egison-tutorial/egison-tutorial-tmp/Main.o )
#5 682.3
#5 682.3 Main.hs:43:22: error:
#5 682.3     Ambiguous occurrence ‘optShowVersion’
#5 682.3     It could refer to
#5 682.3        either ‘Language.Egison.optShowVersion’,
#5 682.3               imported from ‘Language.Egison’ at Main.hs:17:1-32
#5 682.3               (and originally defined in ‘Language.Egison.CmdOptions’)
#5 682.3            or ‘Main.optShowVersion’, defined at Main.hs:51:5
#5 682.3    |
#5 682.3 43 |             Options {optShowVersion = True} -> printVersionNumber
#5 682.3    |                      ^^^^^^^^^^^^^^
#5 682.3
#5 682.3 Main.hs:44:22: error:
#5 682.3     Ambiguous occurrence ‘optPrompt’
#5 682.3     It could refer to
#5 682.3        either ‘Language.Egison.optPrompt’,
#5 682.3               imported from ‘Language.Egison’ at Main.hs:17:1-32
#5 682.3               (and originally defined in ‘Language.Egison.CmdOptions’)
#5 682.3            or ‘Main.optPrompt’, defined at Main.hs:53:5
#5 682.3    |
#5 682.3 44 |             Options {optPrompt = prompt} -> do
#5 682.3    |                      ^^^^^^^^^
#5 682.3
#5 682.3 Main.hs:61:5: error:
#5 682.3     Ambiguous occurrence ‘optShowVersion’
#5 682.3     It could refer to
#5 682.3        either ‘Language.Egison.optShowVersion’,
#5 682.3               imported from ‘Language.Egison’ at Main.hs:17:1-32
#5 682.3               (and originally defined in ‘Language.Egison.CmdOptions’)
#5 682.3            or ‘Main.optShowVersion’, defined at Main.hs:51:5
#5 682.3    |
#5 682.3 61 |     optShowVersion = False,
#5 682.3    |     ^^^^^^^^^^^^^^
#5 682.3
#5 682.3 Main.hs:63:5: error:
#5 682.3     Ambiguous occurrence ‘optPrompt’
#5 682.3     It could refer to
#5 682.3        either ‘Language.Egison.optPrompt’,
#5 682.3               imported from ‘Language.Egison’ at Main.hs:17:1-32
#5 682.3               (and originally defined in ‘Language.Egison.CmdOptions’)
#5 682.3            or ‘Main.optPrompt’, defined at Main.hs:53:5
#5 682.3    |
#5 682.3 63 |     optPrompt = "> ",
#5 682.3    |     ^^^^^^^^^
#5 682.3
#5 682.3 Main.hs:72:28: error:
#5 682.3     Ambiguous occurrence ‘optShowVersion’
#5 682.3     It could refer to
#5 682.3        either ‘Language.Egison.optShowVersion’,
#5 682.3               imported from ‘Language.Egison’ at Main.hs:17:1-32
#5 682.3               (and originally defined in ‘Language.Egison.CmdOptions’)
#5 682.3            or ‘Main.optShowVersion’, defined at Main.hs:51:5
#5 682.3    |
#5 682.3 72 |     (NoArg (\opts -> opts {optShowVersion = True}))
#5 682.3    |                            ^^^^^^^^^^^^^^
#5 682.3
#5 682.3 Main.hs:78:36: error:
#5 682.3     Ambiguous occurrence ‘optPrompt’
#5 682.3     It could refer to
#5 682.3        either ‘Language.Egison.optPrompt’,
#5 682.3               imported from ‘Language.Egison’ at Main.hs:17:1-32
#5 682.3               (and originally defined in ‘Language.Egison.CmdOptions’)
#5 682.3            or ‘Main.optPrompt’, defined at Main.hs:53:5
#5 682.3    |
#5 682.3 78 |     (ReqArg (\prompt opts -> opts {optPrompt = prompt})
#5 682.3    |                                    ^^^^^^^^^
#5 682.3
#5 682.3 Main.hs:169:70: error:
#5 682.3     Not in scope: type constructor or class ‘EgisonTopExpr’
#5 682.3     |
#5 682.3 169 | getEgisonExprOrNewLine :: Options -> InputT IO (Either Bool (String, EgisonTopExpr))
#5 682.3     |                                                                      ^^^^^^^^^^^^^
#5 682.3
#5 682.3 Main.hs:172:81: error:
#5 682.3     Not in scope: type constructor or class ‘EgisonTopExpr’
#5 682.3     |
#5 682.3 172 | getEgisonExprOrNewLine' :: Options -> String -> InputT IO (Either Bool (String, EgisonTopExpr))
#5 682.3     |                                                                                 ^^^^^^^^^^^^^
#5 682.3
#5 682.3 Main.hs:175:35: error:
#5 682.3     Ambiguous occurrence ‘optPrompt’
#5 682.3     It could refer to
#5 682.3        either ‘Language.Egison.optPrompt’,
#5 682.3               imported from ‘Language.Egison’ at Main.hs:17:1-32
#5 682.3               (and originally defined in ‘Language.Egison.CmdOptions’)
#5 682.3            or ‘Main.optPrompt’, defined at Main.hs:53:5
#5 682.3     |
#5 682.3 175 |              "" -> getInputLine $ optPrompt opts
#5 682.3     |                                   ^^^^^^^^^
#5 682.3
#5 682.3 Main.hs:176:55: error:
#5 682.3     Ambiguous occurrence ‘optPrompt’
#5 682.3     It could refer to
#5 682.3        either ‘Language.Egison.optPrompt’,
#5 682.3               imported from ‘Language.Egison’ at Main.hs:17:1-32
#5 682.3               (and originally defined in ‘Language.Egison.CmdOptions’)
#5 682.3            or ‘Main.optPrompt’, defined at Main.hs:53:5
#5 682.3     |
#5 682.3 176 |              _  -> getInputLine $ replicate (length $ optPrompt opts) ' '
#5 682.3     |                                                       ^^^^^^^^^
#5 682.3 cabal: Failed to build exe:egison-tutorial from egison-tutorial-4.0.1. See the
#5 682.3 build log above for details.
...

FROM haskell:8
SHELL ["/bin/bash", "-o", "pipefail", "-c"]
RUN cabal update && \
    cabal install \
    egison-4.1.0 \
    egison-tutorial
WORKDIR /docker
ENTRYPOINT ["egison"]

Cannot be built with Egison 3.10.0

$ cabal v2-build
Resolving dependencies...
Build profile: -w ghc-8.8.1 -O1
In order, the following will be built (use -v for more details):
 - egison-tutorial-3.9.3 (exe:egison-tutorial) (configuration changed)
Configuring executable 'egison-tutorial' for egison-tutorial-3.9.3..
Preprocessing executable 'egison-tutorial' for egison-tutorial-3.9.3..
Building executable 'egison-tutorial' for egison-tutorial-3.9.3..
[1 of 2] Compiling Paths_egison_tutorial ( /egison-tutorial/dist-newstyle/build/x86_64-linux/ghc-8.8.1/egison-tutorial-3.9.3/x/egison-tutorial/build/egison-tutorial/autogen/Paths_egison_tutorial.hs, /egison-tutorial/dist-newstyle/build/x86_64-linux/ghc-8.8.1/egison-tutorial-3.9.3/x/egison-tutorial/build/egison-tutorial/egison-tutorial-tmp/Paths_egison_tutorial.o ) [Optimisation flags changed]
[2 of 2] Compiling Main             ( Main.hs, /egison-tutorial/dist-newstyle/build/x86_64-linux/ghc-8.8.1/egison-tutorial-3.9.3/x/egison-tutorial/build/egison-tutorial/egison-tutorial-tmp/Main.o ) [Optimisation flags changed]

Main.hs:47:35: error:
    Not in scope: ‘ET.defaultOption’
    Module ‘Language.Egison.Types’ does not export ‘defaultOption’.
   |
47 |                 env <- initialEnv ET.defaultOption
   |                                   ^^^^^^^^^^^^^^^^

Main.hs:227:45: error:
    Not in scope: ‘ET.defaultOption’
    Module ‘Language.Egison.Types’ does not export ‘defaultOption’.
    |
227 |         result <- liftIO $ runEgisonTopExpr ET.defaultOption env topExpr
    |                                             ^^^^^^^^^^^^^^^^

I guess this is caused by egison/egison@304dfe8

Update tutorial for new syntax

Approximate value of π²/6

In this line of the tutorial, we calculate an approximate value of (/ (power pi 2) 6).

But we can't show the real value of (/ (power pi 2) 6) in Egison because pi is defined as a symbol π and because it seems that Egison doesn't have f.power currently.

Proposal: Therefore, how about adding a description how to calculate the real value? For example, we can calculate the value by (f./ (f.* f.pi f.pi) 6.0).

言語切り替えオプションの追加

Ambiguous references when installing a tutorial with cabal

Hello, I just wanted to try Egison and install the tutorial. Online version of a tutorial doesn't seem to work for now:

sh: 1: egison-tutorial: not found

I tried to install egison-tutorial via Hackage on Ubuntu 18.04.3 LTS.:

 cabal install egison-tutorial

I was able to install egison itself, but not egison-tutorial app. When I am trying to install it, I see this output:

Failed to install egison-tutorial-3.7.14
Build log ( /home/grid/.cabal/logs/egison-tutorial-3.7.14.log ):
cabal: Entering directory '/tmp/cabal-tmp-30833/egison-tutorial-3.7.14'
Configuring egison-tutorial-3.7.14...
Building egison-tutorial-3.7.14...
Preprocessing executable 'egison-tutorial' for egison-tutorial-3.7.14...
[1 of 2] Compiling Paths_egison_tutorial ( dist/build/autogen/Paths_egison_tutorial.hs, dist/build/egison-tutorial/egison-tutorial-tmp/Paths_egison_tutorial.o )
[2 of 2] Compiling Main             ( Main.hs, dist/build/egison-tutorial/egison-tutorial-tmp/Main.o )

Main.hs:42:22: error:
    Ambiguous occurrence ‘optShowVersion’
    It could refer to either ‘Language.Egison.optShowVersion’,
                             imported from ‘Language.Egison’ at Main.hs:18:1-22
                             (and originally defined in ‘Language.Egison.Types’)
                          or ‘Main.optShowVersion’, defined at Main.hs:50:5

Main.hs:43:22: error:
    Ambiguous occurrence ‘optPrompt’
    It could refer to either ‘Language.Egison.optPrompt’,
                             imported from ‘Language.Egison’ at Main.hs:18:1-22
                             (and originally defined in ‘Language.Egison.Types’)
                          or ‘Main.optPrompt’, defined at Main.hs:52:5

Main.hs:60:5: error:
    Ambiguous occurrence ‘optShowVersion’
    It could refer to either ‘Language.Egison.optShowVersion’,
                             imported from ‘Language.Egison’ at Main.hs:18:1-22
                             (and originally defined in ‘Language.Egison.Types’)
                          or ‘Main.optShowVersion’, defined at Main.hs:50:5

Main.hs:62:5: error:
    Ambiguous occurrence ‘optPrompt’
    It could refer to either ‘Language.Egison.optPrompt’,
                             imported from ‘Language.Egison’ at Main.hs:18:1-22
                             (and originally defined in ‘Language.Egison.Types’)
                          or ‘Main.optPrompt’, defined at Main.hs:52:5

Main.hs:71:28: error:
    Ambiguous occurrence ‘optShowVersion’
    It could refer to either ‘Language.Egison.optShowVersion’,
                             imported from ‘Language.Egison’ at Main.hs:18:1-22
                             (and originally defined in ‘Language.Egison.Types’)
                          or ‘Main.optShowVersion’, defined at Main.hs:50:5

Main.hs:77:36: error:
    Ambiguous occurrence ‘optPrompt’
    It could refer to either ‘Language.Egison.optPrompt’,
                             imported from ‘Language.Egison’ at Main.hs:18:1-22
                             (and originally defined in ‘Language.Egison.Types’)
                          or ‘Main.optPrompt’, defined at Main.hs:52:5
cabal: Leaving directory '/tmp/cabal-tmp-30833/egison-tutorial-3.7.14'
cabal: Error: some packages failed to install:
egison-tutorial-3.7.14 failed during the building phase. The exception was:
ExitFailure 1

Matrix Example

This line :
["[| [| 1 2 |] [| 10 20 30 |] |]"
is supposed to be an example of a matrix. So, it should probably be
["[| [| 1 2 3 |] [| 10 20 30 |] |]".

Prime quadruple example is too heavy for online egison interpreter

The expected answer to the following exercise takes too much time to calculate, and it fails with timeout in the online Egison interpreter.
https://github.com/egison/egison-tutorial/blob/master/Main.hs#L375