From d159ad48390373ff52e64aa679e477716a290607 Mon Sep 17 00:00:00 2001
From: YueLiPicasso <yue.li.picasso@qq.com>
Date: Wed, 14 Sep 2022 17:54:35 +0800
Subject: [PATCH] initial

---
 .gitignore     |   2 +
 README.md      |  44 ++++++++++++-
 catala.lang    | 131 ++++++++++++++++++++++++++++++++++++++
 test.catala_en | 169 +++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 344 insertions(+), 2 deletions(-)
 create mode 100644 .gitignore
 create mode 100644 catala.lang
 create mode 100644 test.catala_en

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..c26bd7a
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+# emacs backupfile
+*~
diff --git a/README.md b/README.md
index a8ee225..7bd8718 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,42 @@
-# Catala-gedit-syntax-highlighting
-GEdit syntax highlighting for Catala
+# GEdit syntax highlighting for Catala
+
+This is to support syntax highlighting of English Catala code in GEdit. 
+
+The code is modelled after the  [Catala syntax highlighting code for the iro compiler](https://github.com/CatalaLang/catala/blob/e7c3ef604e1862dee82a1395ee2a1ea6beb5f9a2/syntax_highlighting/en/catala_en.iro).  
+
+
+## How to use
+
+Copy the file [catala.lang](catala.lang) to the directory below (create if it does not exist) and then 
+restart GEdit. 
+```
+~/.local/share/gtksourceview-4/language-specs
+```
+
+I use [test.catala_en](YCatala.catala_en) as a test file.
+
+## Reference
+
+Here I collect further resources which helped me write the code.
+
+
+The posts below basically say that to provide gedit syntax highlighting support we simply need to write a XML file specifiying the syntax and put it under the gedit syntax highlighting directory.
+```
+https://unix.stackexchange.com/questions/4203/how-can-i-write-a-new-syntax-highlighter-for-gedit
+https://askubuntu.com/questions/55494/how-do-i-add-a-syntax-highlighter-format-to-gedit
+https://github.com/thomasysliu/Gedit-SPICE-syntax-highlighting
+```
+
+Below is a trouble shooting Q&A from a user who successfully added a custom syntax highlighting extension to gedit.
+```
+https://askubuntu.com/questions/295559/how-to-add-a-new-language-definition-for-syntax-highlighting-in-gedit
+```
+
+The definitive guide.
+```
+https://developer-old.gnome.org/gtksourceview/stable/syntax-highlighting-reference.html
+```
+
+
+
+
diff --git a/catala.lang b/catala.lang
new file mode 100644
index 0000000..9394ad2
--- /dev/null
+++ b/catala.lang
@@ -0,0 +1,131 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<language id="catala" name="Catala" version="2.0" _section="Source">
+
+  <metadata>
+    <property name="mimetypes">text/x-catala</property>
+    <property name="globs">*.catala_en</property>
+  </metadata>
+
+  <styles>
+    <style id="keyword-decl" name="Declaration" map-to="def:constant"/>
+    <style id="keyword-rule" name="Rule"        map-to="def:type"/>
+    <style id="keyword-expr" name="Expression"  map-to="def:keyword"/>
+    <style id="comment"      name="Comment"     map-to="def:special-char"/>
+    <style id="primitive"    name="Primitive"   map-to="def:preprocessor"/>
+    <style id="sc_id"        name="Snake-case"  map-to="def:identifier"/>
+    <style id="cc_id"        name="Camel-case"  map-to="def:comment"/>
+  </styles>
+  
+  <definitions>
+  
+    <context id="codeblock">
+      <start>```catala-metadata|```catala</start>
+      <end>```</end>
+      <include>
+	<context ref="comment"/>
+	<context ref="keyword-decl"/>
+	<context ref="keyword-rule"/>
+	<context ref="keyword-expr"/>
+	<context ref="primitive"/>
+	<context ref="operator"/>
+	<context ref="sc_id"/>
+	<context ref="cc_id"/>
+      </include>
+    </context>
+
+    <context id="comment" style-ref="comment">
+      <start>#</start>
+      <end>$</end>
+    </context>
+
+    <context id="keyword-decl" style-ref="keyword-decl">
+      <keyword>declaration</keyword>
+    </context>
+    
+    <context id="keyword-rule" style-ref="keyword-rule">
+      <keyword>context</keyword>
+      <keyword>input</keyword>
+      <keyword>output</keyword>
+      <keyword>internal</keyword>
+      <keyword>scope</keyword>
+      <keyword>depends\s+on</keyword>
+      <keyword>includes</keyword>
+      <keyword>collection</keyword>
+      <keyword>content</keyword>
+      <keyword>optional</keyword>
+      <keyword>structure</keyword>
+      <keyword>enumeration</keyword>
+      <keyword>rule</keyword>
+      <keyword>under\s+condition</keyword>
+      <keyword>condition</keyword>
+      <keyword>data</keyword>
+      <keyword>consequence</keyword>
+      <keyword>fulfilled</keyword>
+      <keyword>equals</keyword>
+      <keyword>assertion</keyword>
+      <keyword>definition</keyword>
+      <keyword>state</keyword>
+      <keyword>label</keyword>
+      <keyword>exception</keyword>
+    </context>
+
+    <context id="keyword-expr" style-ref="keyword-expr">
+      <keyword>match</keyword>
+      <keyword>with\s+pattern</keyword>
+      <keyword>fixed</keyword>
+      <keyword>by</keyword>
+      <keyword>decreasing</keyword>
+      <keyword>increasing</keyword>
+      <keyword>varies</keyword>
+      <keyword>with</keyword>
+      <keyword>we\s+have</keyword>
+      <keyword>let</keyword>
+      <keyword>in</keyword>
+      <keyword>such\s+that</keyword>
+      <keyword>exists</keyword>
+      <keyword>for</keyword>
+      <keyword>all</keyword>
+      <keyword>of</keyword>
+      <keyword>if</keyword>
+      <keyword>then</keyword>
+      <keyword>else</keyword>
+      <keyword>initial</keyword>
+    </context>
+
+    <context id="primitive" style-ref="primitive">
+      <keyword>integer</keyword>
+      <keyword>boolean</keyword>
+      <keyword>date</keyword>
+      <keyword>duration</keyword>
+      <keyword>money</keyword>
+      <keyword>text</keyword>
+      <keyword>decimal</keyword>
+      <keyword>number</keyword>
+      <keyword>sum</keyword>
+    </context>
+
+    <context id="operator" style-ref="keyword-expr">
+      <!--for proper matching, do not allow unnecessary spaces in the following regex-->
+      <match>\.|\s((&lt;=|&lt;|&gt;=|&gt;|\+|-|\*|\/)(\$|\@|\^|\.|)?|not|or|xor|and|year|month|day|!=|=|--)(\s|$)</match>
+    </context>
+
+    <!-- Snake-case identifiers-->
+    <context id="sc_id" style-ref="sc_id">
+      <match>\b[[:lower:]]([[:lower:]]|[[:upper:]]|[0-9]|_|\')*\b</match>
+    </context>
+
+    <!-- Camel-case identifiers-->
+    <context id="cc_id" style-ref="cc_id">
+      <match>\b[[:upper:]]([[:lower:]]|[[:upper:]]|[0-9]|_|\')*\b</match>
+    </context>
+    
+    <!--main context-->
+    <context id="catala">
+      <include>
+	<context ref="codeblock"/>
+      </include>
+    </context>
+    
+  </definitions>
+</language>
diff --git a/test.catala_en b/test.catala_en
new file mode 100644
index 0000000..7c8fd05
--- /dev/null
+++ b/test.catala_en
@@ -0,0 +1,169 @@
+# Fictional Income Tax Rules
+
+## Article 1
+
+The income tax for an individual is defined 
+as a fixed percentage of the individual's 
+income over a year.
+
+```catala-metadata
+declaration structure Individual :
+  data income             content money
+  data number_of_children content integer
+# like OCaml record type
+	
+declaration enumeration TaxCredit :
+  -- NoTaxCredit
+  -- ChildrenTaxCredit content integer  
+# like OCaml algebraic data type
+
+declaration scope IncomeTaxComputation :
+  input    individual       content Individual
+  internal fixed_percentage content decimal
+  output   income_tax       content money
+  
+# like OCaml function type declaration
+# a variable can be both input and output
+```
+
+```catala
+scope IncomeTaxComputation :
+  definition income_tax equals
+  individual.income *$ fixed_percentage
+  # *$ is multiplication (*) with money ($)
+```
+
+## Article 2
+
+The fixed percentage mentioned at article 1 is equal to 20 %.
+
+```catala
+# distributed definition
+scope IncomeTaxComputation:
+  definition fixed_percentage equals 20 %
+```
+
+## Article 3
+
+If the individual is in charge of 2 or more 
+children, then the fixed percentage mentioned 
+at article 1 is equal to 15 %.
+
+```catala
+scope IncomeTaxComputation :
+  definition fixed_percentage under condition
+    individual.number_of_children >= 2
+  consequence equals 15 %  
+```
+
+### Article 3 bis 
+
+The children eligible for application of article 3. 
+
+```catala
+# can I use catala-metadata here? 
+
+declaration scope Child :
+  input age                    content integer
+  output is_eligible_article_3 condition
+  # "condition" is like "content bool"
+  
+scope Child: 
+  rule is_eligible_article_3 under condition
+    age < 18
+  consequence fulfilled
+  # "rule" is like "define", but set conditions 
+  # to either true or false.
+  # fulfilled is like "equals true"
+```
+
+```catala-metadata
+declaration structure TwoBrackets:
+  data breakpoint content money
+  data rate1      content decimal
+  data rate2      content decimal
+  
+declaration scope TwoBracketsTaxComputation:
+  input brackets     content TwoBrackets
+  output tax_formula content money depends on money
+  # the output has a function type 
+```
+
+## Article 4
+
+The tax amount for a two-brackets computation is 
+equal to the amount of income in each bracket 
+multiplied by the rate of each bracket.
+
+```catala
+scope TwoBracketsTaxComputation:
+  definition tax_formula of income equals
+    # "income" is a formal parameter of the function
+    if income <=$ brackets.breakpoint then
+      income *$ brackets.rate1
+    else (
+      brackets.breakpoint *$ brackets.rate1 +$
+      (income -$ brackets.breakpoint) *$ 
+      brackets.rate2
+    )    
+```
+
+## Article 5
+
+For individuals whose income is greater than 
+$100,000, the income tax of article 1 is 40% 
+of the income above $100,000. Below $100,000, 
+the income tax is 20% of the income.
+
+```catala
+declaration scope NewIncomeTaxComputation:
+  two_brackets scope TwoBracketsTaxComputation
+  # add a subscope to context
+  input  individual content Individual
+  output income_tax content money
+  
+scope NewIncomeTaxComputation:
+  definition two_brackets.brackets equals    
+    TwoBrackets {
+    -- breakpoint : $100,000
+    -- rate1 : 20%
+    -- rate2 : 40% 
+    } 
+  # we have now provided the input to the subscope,
+  # which is then expected to return a function
+  definition income_tax equals 
+    two_brackets.tax_formula of individual.income
+```
+
+## Article 6
+
+Individuals earning less than $10,000 are exempted 
+of the income tax mentioned at article 1.
+
+```catala
+scope NewIncomeTaxComputation :
+ definition income_tax under condition
+   individual.income <=$ $10,000
+ consequence equals $0
+```
+
+## Tests
+
+```catala
+declaration scope Test1 :
+  tax_computation scope NewIncomeTaxComputation
+  output income_tax content money
+  
+scope Test1 :
+  definition tax_computation.individual equals
+    Individual {
+      -- income : $700,000 
+      # try also 7,000
+      -- number_of_children : 0
+    }  
+  definition income_tax equals 
+    tax_computation.income_tax 
+  assertion income_tax = $260,000 
+```
+
+