Merge branch 'awesome-intro' of https://github.com/sachinkamath/explore-git into sachkat1

Author: oyeb

.gitignore

@@ -26,3 +26,12 @@
 *.exe
 *.out
 *.app
+
+# Code Blocks things
+*.cbp
+*.depend
+*.layout
+
+# Other
+
+*wiki*

CONTRIBUTING.md

@@ -1,5 +1,10 @@
 #CONTRIBUTING
 
+Fork this repo, make changes, test code, submit pr.
+***
+***Comment on the issue to let everyone know you are working on it. Why should 14 people develop just 1 feature which can be developed by a far less number of people and there are numerous other things to work on?
+Be responsible.***
+***
 The aim of the event is to **Teach Git Hands-On**. Due to time constraints, the projects we provide for hacking ***cannot***
 
 - be difficult, the aim is to learn `git` and not computer science.

cpp/liquid/Makefile

@@ -0,0 +1,66 @@
+# ADD THE SOURCE FILE NAME THAT YOU HAVE JUST CREATED to the `src_files` VARIABLE.
+# FOLLOW THE CONVENTION:
+# 		prefix function name with `ml_`
+# 
+# run:
+# 
+# $ make liquid
+# 
+# YOU'LL FIND AN EXECUTABLE CALLED `liquid`
+# 
+# launch it using 
+# 
+# $ ./liquid
+
+# ADD THE FILE NAME HERE
+# \/\/\/\/\/\/\/\/\/\/\/
+src_files = ml_add \
+			ml_sub \
+			ml_mul \
+			ml_div \
+			ml_mod \
+			ml_power \
+			ml_perms \
+			ml_combos \
+			ml_isPrime \
+			ml_nextPrime \
+			ml_factorial \
+			ml_factorise \
+			ml_gcd \
+			ml_lcm
+
+#^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^#
+# 				 DON'T TOUCH BELOW THIS           #
+#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~#
+
+srcdir = src/
+build_dir = build/
+
+DEPS = math-lib.h
+
+CFLAGS = -Wall -std=c99 -c -I. -I$(srcdir)
+LDFLAGS = -lm
+SOURCES = $(src_files:%=$(srcdir)%.cpp)
+OBJECTS = $(src_files:%=$(build_dir)%.o)
+
+# $@ is TARGET
+# $< is first pre-requisite
+# $^ is space-separated list of all pre-requisites
+
+$(build_dir)%.o: $(srcdir)%.c $(srcdir)math-lib.h
+	$(CC) $(CFLAGS) $< -o $@ $(LDFLAGS)
+
+%.o: %.c shunting-yard.h stack.h $(DEPS)
+	$(CC) $(CFLAGS) $< -o $@ $(LDFLAGS)
+
+liquid: liquid.o $(OBJECTS) shunting-yard.o stack.o
+	$(CC) -Wall -std=c99 -I $(srcdir) -I. $? -o $@ $(LDFLAGS)
+
+again: clean liquid
+
+test:
+	./liquid
+
+clean:
+	@rm build/*.[ao]
+	@rm *.[ao]

cpp/liquid/README.md

@@ -0,0 +1,50 @@
+#The `liquid` 
+
+`liquid` is a simple CLI math application that can solve simple math problems.
+
+#How is the code organised?
+
+This is the directory structure:
+```
+└── liquid
+    ├── liquid.cpp
+    ├── testing.cpp
+    ├── shunting-yard.cpp
+    ├── shunting-yard.h
+    ├── Makefile
+    └── src
+        ├── math-lib.h
+        ├── ml_add.cpp
+        ├── ml_div.cpp
+        ├── ml_mul.cpp
+        ├── ml_sub.cpp
+        ├── .
+        ├── .
+        ├── .
+        └── ml_*****.cpp
+```
+
+
+We've already made the CLI which can be used to input a math expression and get the result.
+>Credit: @bamos for implementing the Shunting-Yard Algorithm in `cpp`.
+It's basically the RPN expression parser, which pushes into a `stack` to parse an expression and then evaluate based on priority rules by `popping` the `stack`.
+
+The name of the CLI file is `liquid.cpp`. *You don't have to edit `liquid.cpp`.*
+
+#What do I edit?
+
+See the `src/` directory? Read `math-lib.h`. This is the list of functions that provide the computational functionality to `liquid`.
+```
+double ml_add(double, double);
+double ml_mul(double, double);
+double ml_div(double, double);
+double ml_sub(double, double);
+
+```
+But, except the `add`, `mul`, `div`, and `sub`, files, the rest are empty.
+And there's also a template file (`ml_template.cpp`).
+
+#Appendix
+
+**CLI**
+*Command Line Interface. It means a* **terminal** *is opened for the user, not a GUI.*

cpp/liquid/liquid.c

@@ -0,0 +1,38 @@
+#include "shunting-yard.h"
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+/*
+ *	DONT EDIT THIS FILE!
+ *	See the wiki, for a list of keywords that are understood by Liquid.
+*/
+
+void strip_wspace(char *ipstr, char* stripped){
+	int i, j = 0;		
+	for (i=0; ipstr[i] != '\0' && i<99; i++){
+		if (ipstr[i] != ' ')
+			stripped[j++] = ipstr[i];
+	}
+	stripped[j] = '\0';
+	//printf("%s\n", stripped);
+}
+
+int main(int agrc, char *argv[]){
+	double result;
+	char input[100], stripped[100];
+	int i,j;
+	//Introduction 
+	system("cowsay 'Welcome to the awesome calculator. Moo!'");
+	printf("Liquid is a smooth CLI math expression evaluator.\nEnter expressions, you need to match all parens.\n\nSee the wiki to know the keywords understood by Liquid\nTo quit just type 'Q'\n");
+	while(1)
+	{
+		printf("<< ");
+		gets(input);
+		if(strcmp(input,"Q")==0)
+			break;
+		strip_wspace(input, stripped);
+		Status response = shunting_yard(stripped, &result);
+		printf(">> %f\n", result);
+	}
+	return 0;
+}