Modernized Haskell training sessions

README.md

@@ -11,11 +11,19 @@ the team.
 
 ### Slides
 
-The slides use LaTeX. You'll need `xelatex` installed to build them. Simply
-run `make` to create the PDFs. You must also have the [Yanone
+The slides use LaTeX. Simply run `make` to create the PDFs, assuming you have
+all the required dependencies.
+
+You need `xelatex` and the [Yanone
 Kaffeesatz](https://yanone.de/fonts/kaffeesatz/) fonts installed on your
 machine.
 
+On an Ubuntu system, you can get all of these by running
+
+```
+sudo apt-get install texlive-xetex texlive-fonts-extra fonts-yanone-kaffeesatz
+```
+
 ### Exercises
 
 The codelabs only require ghc to be installed and in the path. Please read

haskell_101/codelab/00_setup/Makefile

@@ -0,0 +1,45 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+.DEFAULT_GOAL := run
+.PHONY: repl run clean
+
+TARGET = codelab
+
+TOOL = .tool
+REPL = .repl_tool
+BUILD_GENERATED = dist dist-newstyle .stack-work stack.yaml.lock $(TOOL) $(REPL)
+
+repl: $(REPL)
+	@`cat $(REPL)` :$(TARGET)
+
+run: $(TOOL)
+	@`cat $(TOOL)` run $(TARGET)
+
+clean:
+	@$(RM) -r $(BUILD_GENERATED)
+
+#
+# Private rules to check which toolchain is available
+#
+
+$(TOOL):
+	@([[ -e `which stack` ]] && echo stack > $(TOOL) || true)
+	@([[ -s $(TOOL) ]] || ([[ -e `which cabal` ]] && echo cabal > $(TOOL)) || true)
+	@([[ -s $(TOOL) ]] || (cat setup.md && false))
+
+$(REPL):
+	@([[ -e `which stack` ]] && echo stack > $(TOOL) || true)
+	@([[ -s $(REPL) ]] || ([[ -e `which cabal` ]] && echo cabal repl > $(REPL)) || true)
+	@([[ -s $(REPL) ]] || (cat setup.md && false))

haskell_101/codelab/00_setup/Setup.hs

@@ -0,0 +1,16 @@
+-- Copyright 2021 Google LLC
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     https://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+
+import Distribution.Simple
+main = defaultMain

haskell_101/codelab/00_setup/codelab.cabal

@@ -0,0 +1,32 @@
+-- Copyright 2021 Google LLC
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     https://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+
+name:               codelab
+version:            0.1.0.0
+build-type:         Simple
+cabal-version:      >=1.10
+
+executable codelab
+  hs-source-dirs:   src
+  default-language: Haskell2010
+  main-is:          Main.hs
+  build-depends:
+      base >=4.11 && <4.15
+
+executable solution
+  hs-source-dirs:   src
+  default-language: Haskell2010
+  main-is:          Main.hs
+  build-depends:
+      base >=4.11 && <4.15

haskell_101/codelab/00_setup/setup.md

@@ -0,0 +1,16 @@
+============================================
+
+             HASKELL 101
+
+============================================
+
+If you are reading this text, probably you don't have Haskell environment setup
+on your system. This should give you enough instructions to install it.
+
+First, note that there are two different ways to get Haskell installed:
+
+1. using [Stack](https://docs.haskellstack.org/en/stable/README/)
+2. getting the [Haskell Platform](https://www.haskell.org/platform/)
+
+This course is not taking any side, you are free to install either of these. The
+links above point to the install pages for either of the toolchains.

haskell_101/codelab/00_setup/src/Main.hs

@@ -0,0 +1,23 @@
+-- Copyright 2021 Google LLC
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     https://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+
+module Main where
+
+main :: IO ()
+main = do
+  putStrLn "============================================"
+  putStrLn ""
+  putStrLn "Haskell toolchain is installed! All is good."
+  putStrLn ""
+  putStrLn "============================================"

haskell_101/codelab/00_setup/stack.yaml

@@ -0,0 +1,17 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+resolver: lts-14.25
+packages:
+- .

haskell_101/codelab/01_functions/Makefile

@@ -0,0 +1,45 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+.DEFAULT_GOAL := run
+.PHONY: repl run clean
+
+TARGET = codelab
+
+TOOL = .tool
+REPL = .repl_tool
+BUILD_GENERATED = dist dist-newstyle .stack-work stack.yaml.lock $(TOOL) $(REPL)
+
+repl: $(REPL)
+	@`cat $(REPL)` :$(TARGET)
+
+run: $(TOOL)
+	@`cat $(TOOL)` run $(TARGET)
+
+clean:
+	@$(RM) -r $(BUILD_GENERATED)
+
+#
+# Private rules to check which toolchain is available
+#
+
+$(TOOL):
+	@([[ -e `which stack` ]] && echo stack > $(TOOL) || true)
+	@([[ -s $(TOOL) ]] || ([[ -e `which cabal` ]] && echo cabal > $(TOOL)) || true)
+	@([[ -s $(TOOL) ]] || (cat setup.md && false))
+
+$(REPL):
+	@([[ -e `which stack` ]] && echo stack > $(TOOL) || true)
+	@([[ -s $(REPL) ]] || ([[ -e `which cabal` ]] && echo cabal repl > $(REPL)) || true)
+	@([[ -s $(REPL) ]] || (cat setup.md && false))

haskell_101/codelab/01_functions/Setup.hs

@@ -0,0 +1,16 @@
+-- Copyright 2021 Google LLC
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     https://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+
+import Distribution.Simple
+main = defaultMain

haskell_101/codelab/01_functions/codelab.cabal

@@ -0,0 +1,41 @@
+-- Copyright 2021 Google LLC
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     https://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+
+name:               codelab
+version:            0.1.0.0
+build-type:         Simple
+cabal-version:      >=1.10
+
+executable codelab
+  hs-source-dirs:   src
+  default-language: Haskell2010
+  main-is:          Main.hs
+  other-modules:
+      Codelab
+    , Internal
+  build-depends:
+      base >=4.11 && <4.15
+    , ansi-terminal >= 0.8.0.4
+
+executable solution
+  hs-source-dirs:   src
+  default-language: Haskell2010
+  main-is:          Main.hs
+  cpp-options:      -DSOLUTION
+  other-modules:
+      Solution
+    , Internal
+  build-depends:
+      base >=4.11 && <4.15
+    , ansi-terminal >= 0.8.0.4

haskell_101/codelab/01_functions/setup.md

@@ -0,0 +1,16 @@
+============================================
+
+             HASKELL MTV 101
+
+============================================
+
+If you are reading this text, probably you don't have Haskell environment setup
+on your system. This should give you enough instructions to install it.
+
+First, note that there are two different ways to get Haskell installed:
+
+1. using [Stack](https://docs.haskellstack.org/en/stable/README/)
+2. getting the [Haskell Platform](https://www.haskell.org/platform/)
+
+This course is not taking any side, you are free to install either of these. The
+links above point to the install pages for either of the toolchains.

haskell_101/codelab/01_functions/src/Codelab.hs

@@ -0,0 +1,65 @@
+-- Copyright 2021 Google LLC
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     https://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
+{-# OPTIONS_GHC -fno-warn-unused-matches #-}
+{-# OPTIONS_GHC -fno-warn-unused-binds   #-}
+{-# OPTIONS_GHC -fno-warn-type-defaults  #-}
+
+module Codelab where
+
+import Internal (codelab)
+import Prelude hiding (gcd)
+
+-- CODELAB 01: Number manipulation
+--
+-- As we have not looked at any complex data structures yet, the only thing
+-- we have for now is numbers.
+
+add :: Int -> Int -> Int
+add x y = codelab
+
+subtract :: Int -> Int -> Int
+subtract x y = codelab
+
+double :: Int -> Int
+double x = codelab
+
+multiply :: Int -> Int -> Int
+multiply x y = codelab
+
+-- Note that Haskell is strict about types even for basic integral types.
+-- Int is never automatically converted to Double.  But you can use
+-- fromIntegral to convert from any integral type to any number type.
+divide :: Int -> Int -> Double
+divide x y = codelab
+
+-- Remember that you can use if/then/else:
+--
+--  if <expr> then <expr> else <expr>
+--
+-- Integer is just like Int, except that it can store arbitrarily large
+-- numbers. Without a type like this, we couldn't compute the factorial of
+-- even relatively small numbers.
+--
+-- Remember that function application binds tighter than operators!
+-- E.g.: `3 * f 4` is the same as `3 * (f 4)`, not `(3 * f) 4`.
+factorial :: Integer -> Integer
+factorial n = codelab
+
+-- Consider Euclid's algorithm:
+--
+--   https://en.wikipedia.org/wiki/Greatest_common_divisor#Euclid's_algorithm
+gcd :: Int -> Int -> Int
+gcd a b = codelab