2022-10-25 17:10:17 -03:00
25 changed files with 1246 additions and 0 deletions
--- a/.clang-format
+++ b/.clang-format
@ -0,0 +1,220 @@
+---
+AccessModifierOffset: 0
+EmptyLineAfterAccessModifier: Never
+EmptyLineBeforeAccessModifier: Always
+IndentAccessModifiers: true
+TabWidth: 4
+UseTab: Never
+UseCRLF: false
+Language: Cpp
+IndentWidth: 4
+AlignAfterOpenBracket: DontAlign
+AlignArrayOfStructures: Left
+AlignConsecutiveAssignments: AcrossComments
+AlignConsecutiveBitFields: AcrossComments
+AlignConsecutiveDeclarations: None
+AlignConsecutiveMacros: AcrossComments
+AlignEscapedNewlines: Left
+AlignOperands: AlignAfterOperator
+AlignTrailingComments: true
+AllowAllArgumentsOnNextLine: false
+AllowAllConstructorInitializersOnNextLine: false
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortBlocksOnASingleLine: Never
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortEnumsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: None
+AllowShortIfStatementsOnASingleLine: Never
+AllowShortLambdasOnASingleLine: None
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterDefinitionReturnType: None
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+AlwaysBreakTemplateDeclarations: No
+BinPackArguments: false
+BinPackParameters: false
+AttributeMacros:
+  - __capability
+BitFieldColonSpacing: Both
+BraceWrapping:
+  AfterCaseLabel: true
+  AfterClass: true
+  AfterControlStatement: Always
+  AfterEnum: true
+  AfterFunction: true
+  AfterNamespace: true
+  AfterObjCDeclaration: true
+  AfterStruct: true
+  AfterUnion: true
+  AfterExternBlock: true
+  BeforeCatch: true
+  BeforeElse: true
+  BeforeLambdaBody: true
+  BeforeWhile: true
+  IndentBraces: false
+  SplitEmptyFunction: true
+  SplitEmptyRecord: true
+  SplitEmptyNamespace: true
+BreakBeforeBraces: Custom
+BreakAfterJavaFieldAnnotations: false
+BreakBeforeBinaryOperators: All
+BreakBeforeConceptDeclarations: false
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializers: AfterColon
+BreakInheritanceList: AfterColon
+BreakStringLiterals: false
+ColumnLimit: 80
+CommentPragmas: "^ IWYU pragma:"
+CompactNamespaces: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: true
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: true
+DeriveLineEnding: true
+DerivePointerAlignment: true
+DisableFormat: false
+ExperimentalAutoDetectBinPacking: false
+FixNamespaceComments: true
+ForEachMacros:
+  - foreach
+  - Q_FOREACH
+  - BOOST_FOREACH
+IfMacros:
+  - KJ_IF_MAYBE
+IncludeBlocks: Regroup
+IncludeCategories:
+  - Regex: ^<ext/.*\.h>
+    Priority: 2
+    CaseSensitive: false
+    SortPriority: 0
+  - Regex: ^<.*\.h>
+    Priority: 1
+    CaseSensitive: false
+    SortPriority: 0
+  - Regex: ^<.*
+    Priority: 2
+    CaseSensitive: false
+    SortPriority: 0
+  - Regex: .*
+    Priority: 0
+    CaseSensitive: false
+    SortPriority: 0
+IncludeIsMainRegex: ([-_](test|unittest))?$
+IncludeIsMainSourceRegex: ""
+IndentCaseBlocks: true
+IndentCaseLabels: true
+IndentExternBlock: Indent
+IndentGotoLabels: false
+IndentPPDirectives: BeforeHash
+IndentRequires: true
+IndentWrappedFunctionNames: true
+InsertTrailingCommas: None
+JavaScriptQuotes: Double
+JavaScriptWrapImports: true
+KeepEmptyLinesAtTheStartOfBlocks: false
+LambdaBodyIndentation: OuterScope
+MacroBlockBegin: ""
+MacroBlockEnd: ""
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: All
+ObjCBinPackProtocolList: Never
+ObjCBlockIndentWidth: 4
+ObjCBreakBeforeNestedBlockParam: false
+ObjCSpaceAfterProperty: true
+ObjCSpaceBeforeProtocolList: true
+PPIndentWidth: 4
+PackConstructorInitializers: Never
+PenaltyBreakAssignment: 2
+PenaltyBreakBeforeFirstCallParameter: 1
+PenaltyBreakComment: 300
+PenaltyBreakFirstLessLess: 120
+PenaltyBreakOpenParenthesis: 0
+PenaltyBreakString: 1000
+PenaltyBreakTemplateDeclaration: 10
+PenaltyExcessCharacter: 1000000
+PenaltyIndentedWhitespace: 0
+PenaltyReturnTypeOnItsOwnLine: 200
+PointerAlignment: Left
+QualifierAlignment: Left
+RawStringFormats:
+  - Language: Cpp
+    BasedOnStyle: google
+    Delimiters:
+      - cc
+      - CC
+      - cpp
+      - Cpp
+      - CPP
+      - c++
+      - C++
+    CanonicalDelimiter: ""
+  - Language: TextProto
+    EnclosingFunctions:
+      - EqualsProto
+      - EquivToProto
+      - PARSE_PARTIAL_TEXT_PROTO
+      - PARSE_TEST_PROTO
+      - PARSE_TEXT_PROTO
+      - ParseTextOrDie
+      - ParseTextProtoOrDie
+      - ParseTestProto
+      - ParsePartialTestProto
+    BasedOnStyle: google
+    Delimiters:
+      - pb
+      - PB
+      - proto
+      - PROTO
+    CanonicalDelimiter: pb
+ReferenceAlignment: Left
+ReflowComments: false
+RemoveBracesLLVM: false
+SeparateDefinitionBlocks: Always
+ShortNamespaceLines: 0
+SortIncludes: CaseSensitive
+SortJavaStaticImport: Before
+SortUsingDeclarations: true
+SpaceAfterCStyleCast: true
+SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: false
+SpaceAroundPointerQualifiers: Default
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCaseColon: true
+SpaceBeforeCpp11BracedList: true
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeParens: Custom
+SpaceBeforeParensOptions:
+  AfterControlStatements: true
+  AfterForeachMacros: false
+  AfterFunctionDeclarationName: false
+  AfterFunctionDefinitionName: false
+  AfterIfMacros: false
+  AfterOverloadedOperator: true
+  BeforeNonEmptyParentheses: false
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceBeforeSquareBrackets: false
+SpaceInEmptyBlock: false
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles: Never
+SpacesInCStyleCastParentheses: false
+SpacesInConditionalStatement: false
+SpacesInContainerLiterals: false
+SpacesInLineCommentPrefix:
+  Minimum: 1
+  Maximum: 1
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+Standard: Auto
+StatementAttributeLikeMacros:
+  - Q_EMIT
+StatementMacros:
+  - Q_UNUSED
+  - QT_REQUIRE_VERSION
+WhitespaceSensitiveMacros:
+  - STRINGIZE
+  - PP_STRINGIZE
+  - BOOST_PP_STRINGIZE
+  - NS_SWIFT_NAME
+  - CF_SWIFT_NAME
--- a/.gitignore
+++ b/.gitignore
@ -1 +1,3 @@
 *.code-workspace
+.vscode
+builddir
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@ -0,0 +1,33 @@
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+repos:
+    - repo: https://github.com/pre-commit/pre-commit-hooks
+      rev: v4.3.0
+      hooks:
+          - id: trailing-whitespace
+          - id: end-of-file-fixer
+          - id: check-case-conflict
+          - id: mixed-line-ending
+          - id: check-added-large-files
+          - id: check-executables-have-shebangs
+          - id: check-shebang-scripts-are-executable
+          - id: detect-private-key
+          - id: no-commit-to-branch
+            args: [--branch, master, --branch, develop]
+    - repo: https://github.com/pre-commit/mirrors-clang-format
+      rev: v14.0.6
+      hooks:
+          - id: clang-format
+            types_or: [c++, c]
+            args: ["-style=file"]
+    - repo: https://github.com/Lucas-C/pre-commit-hooks
+      rev: v1.3.1
+      hooks:
+          - id: forbid-crlf
+          - id: forbid-tabs
+#-   repo: https://github.com/pocc/pre-commit-hooks
+#    rev: v1.3.5
+#    hooks:
+#    -   id: clang-tidy
+#        args: [-checks=clang-diagnostic-return-type]
+#        files: src/.*\.cpp
--- a/compile_commands.json
+++ b/compile_commands.json
@ -0,0 +1,20 @@
+[
+  {
+    "directory": "/mnt/data/ubb/courses/proyecto-titulo/obelisk/builddir",
+    "command": "clang++ -Isrc/obelisk.p -Isrc -I../src -fcolor-diagnostics -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wnon-virtual-dtor -Wextra -Wpedantic -std=c++17 -O0 -g -MD -MQ src/obelisk.p/obelisk.cpp.o -MF src/obelisk.p/obelisk.cpp.o.d -o src/obelisk.p/obelisk.cpp.o -c ../src/obelisk.cpp",
+    "file": "../src/obelisk.cpp",
+    "output": "src/obelisk.p/obelisk.cpp.o"
+  },
+  {
+    "directory": "/mnt/data/ubb/courses/proyecto-titulo/obelisk/builddir",
+    "command": "clang++ -Isrc/obelisk.p -Isrc -I../src -fcolor-diagnostics -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wnon-virtual-dtor -Wextra -Wpedantic -std=c++17 -O0 -g -MD -MQ src/obelisk.p/lexer.cpp.o -MF src/obelisk.p/lexer.cpp.o.d -o src/obelisk.p/lexer.cpp.o -c ../src/lexer.cpp",
+    "file": "../src/lexer.cpp",
+    "output": "src/obelisk.p/lexer.cpp.o"
+  },
+  {
+    "directory": "/mnt/data/ubb/courses/proyecto-titulo/obelisk/builddir",
+    "command": "clang++ -Isrc/obelisk.p -Isrc -I../src -fcolor-diagnostics -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wnon-virtual-dtor -Wextra -Wpedantic -std=c++17 -O0 -g -MD -MQ src/obelisk.p/parser.cpp.o -MF src/obelisk.p/parser.cpp.o.d -o src/obelisk.p/parser.cpp.o -c ../src/parser.cpp",
+    "file": "../src/parser.cpp",
+    "output": "src/obelisk.p/parser.cpp.o"
+  }
+]
--- a/meson.build
+++ b/meson.build
@ -0,0 +1,11 @@
+project('obelisk',
+    'cpp',
+    version : '1.0.0',
+    default_options : [
+        'warning_level=3',
+        'c_std=c17',
+        'cpp_std=c++17'
+    ]
+)
+
+subdir('src')
--- a/src/ast/call_expression_ast.h
+++ b/src/ast/call_expression_ast.h
@ -0,0 +1,34 @@
+#ifndef OBELISK_AST_CALL_EXPRESSION_AST_H
+#define OBELISK_AST_CALL_EXPRESSION_AST_H
+
+#include "ast/expression_ast.h"
+
+#include <memory>
+#include <string>
+#include <vector>
+
+namespace obelisk
+{
+    class CallExpressionAST : public ExpressionAST
+    {
+        private:
+            std::string callee_;
+            std::vector<std::unique_ptr<ExpressionAST>> args_;
+
+            std::string getCallee();
+            void setCallee(std::string callee);
+
+            std::vector<std::unique_ptr<ExpressionAST>> getArgs();
+            void setArgs(std::vector<std::unique_ptr<ExpressionAST>> args);
+
+        public:
+            CallExpressionAST(const std::string &callee,
+                std::vector<std::unique_ptr<ExpressionAST>> args) :
+                callee_(callee),
+                args_(std::move(args))
+            {
+            }
+    };
+} // namespace obelisk
+
+#endif
--- a/src/ast/expression_ast.h
+++ b/src/ast/expression_ast.h
@ -0,0 +1,13 @@
+#ifndef OBELISK_AST_EXPRESSION_AST_H
+#define OBELISK_AST_EXPRESSION_AST_H
+
+namespace obelisk
+{
+    class ExpressionAST
+    {
+        public:
+            virtual ~ExpressionAST() = default;
+    };
+} // namespace obelisk
+
+#endif
--- a/src/ast/function_ast.h
+++ b/src/ast/function_ast.h
@ -0,0 +1,30 @@
+#ifndef OBELISK_AST_FUNCTION_AST_H
+#define OBELISK_AST_FUNCTION_AST_H
+
+#include "ast/expression_ast.h"
+#include "ast/prototype_ast.h"
+
+#include <memory>
+
+namespace obelisk
+{
+    class FunctionAST
+    {
+        private:
+            std::unique_ptr<PrototypeAST> prototype_;
+            std::unique_ptr<ExpressionAST> body_;
+
+            std::unique_ptr<PrototypeAST> getPrototype();
+            void setPrototype(std::unique_ptr<PrototypeAST> prototype);
+
+        public:
+            FunctionAST(std::unique_ptr<PrototypeAST> prototype,
+                std::unique_ptr<ExpressionAST> body) :
+                prototype_(std::move(prototype)),
+                body_(std::move(body))
+            {
+            }
+    };
+} // namespace obelisk
+
+#endif
--- a/src/ast/meson.build
+++ b/src/ast/meson.build
@ -0,0 +1,8 @@
+obelisk_ast_sources = files(
+    'call_expression_ast.h',
+    'expression_ast.h',
+    'function_ast.h',
+    'number_expression_ast.h',
+    'prototype_ast.h',
+    'variable_expression_ast.h'
+)
--- a/src/ast/number_expression_ast.h
+++ b/src/ast/number_expression_ast.h
@ -0,0 +1,24 @@
+#ifndef OBELISK_AST_NUMBER_EXPRESSION_AST_H
+#define OBELISK_AST_NUMBER_EXPRESSION_AST_H
+
+#include "ast/expression_ast.h"
+
+namespace obelisk
+{
+    class NumberExpressionAST : public ExpressionAST
+    {
+        private:
+            double number_;
+
+            double getNumber();
+            void setNumber(double number);
+
+        public:
+            NumberExpressionAST(double number) :
+                number_(number)
+            {
+            }
+    };
+} // namespace obelisk
+
+#endif
--- a/src/ast/prototype_ast.h
+++ b/src/ast/prototype_ast.h
@ -0,0 +1,34 @@
+#ifndef OBELISK_AST_PROTOTYPE_AST_H
+#define OBELISK_AST_PROTOTYPE_AST_H
+
+#include <string>
+#include <vector>
+
+namespace obelisk
+{
+    class PrototypeAST
+    {
+        private:
+            std::string name_;
+            std::vector<std::string> args_;
+
+            void setName(const std::string& name);
+            std::vector<std::string> getArgs();
+            void setArgs(std::vector<std::string> args);
+
+        public:
+            PrototypeAST(const std::string& name,
+                std::vector<std::string> args) :
+                name_(name),
+                args_(std::move(args))
+            {
+            }
+
+            const std::string& getName() const
+            {
+                return name_;
+            }
+    };
+} //namespace obelisk
+
+#endif
--- a/src/ast/variable_expression_ast.h
+++ b/src/ast/variable_expression_ast.h
@ -0,0 +1,25 @@
+#ifndef OBELISK_AST_VARIABLE_EXPRESSION_AST_H
+#define OBELISK_AST_VARIABLE_EXPRESSION_AST_H
+
+#include "ast/expression_ast.h"
+
+#include <string>
+
+namespace obelisk
+{
+    class VariableExpressionAST : public ExpressionAST
+    {
+        private:
+            std::string name_;
+            std::string getName();
+            void setName(const std::string name);
+
+        public:
+            VariableExpressionAST(const std::string &name) :
+                name_(name)
+            {
+            }
+    };
+} //namespace obelisk
+
+#endif
--- a/src/knowledge_base.cpp
+++ b/src/knowledge_base.cpp
@ -0,0 +1,59 @@
+#include "knowledge_base.h"
+
+#include <iostream>
+
+const std::string obelisk::Sql::create_facts_table
+    = "CREATE TABLE fact (id INT PRIMARY KEY NOT NULL);";
+
+obelisk::KnowledgeBase::KnowledgeBase(const char* filename)
+{
+    KnowledgeBase(filename, DEFAULT_FLAGS);
+}
+
+obelisk::KnowledgeBase::KnowledgeBase(const char* filename, int flags)
+{
+    filename_ = std::move(filename);
+    flags_    = std::move(flags);
+
+    auto result = sqlite3_open_v2(filename, &dbConnection_, flags, NULL);
+    if (result != SQLITE_OK)
+    {
+        logSqliteError(result);
+    }
+
+    char* tmp;
+    result = sqlite3_exec(dbConnection_,
+        obelisk::Sql::create_facts_table.c_str(),
+        NULL,
+        NULL,
+        &tmp);
+    if (tmp)
+    {
+        std::string errmsg(tmp);
+        throw obelisk::KnowledgeBaseException(errmsg);
+    }
+}
+
+obelisk::KnowledgeBase::~KnowledgeBase()
+{
+    sqlite3_close_v2(dbConnection_);
+}
+
+// TODO: log files?
+void obelisk::KnowledgeBase::logSqliteError(int result)
+{
+    std::cout << sqlite3_errstr(result) << std::endl;
+}
+
+void obelisk::KnowledgeBase::getFloat(float* result1,
+    float* result2,
+    double var)
+{
+    *result1 = (float) var;
+    *result2 = (float) (var - (double) *result1);
+}
+
+void obelisk::KnowledgeBase::getDouble(double* result, float var1, float var2)
+{
+    *result = (double) ((double) var2 + (double) var1);
+}
--- a/src/knowledge_base.h
+++ b/src/knowledge_base.h
@ -0,0 +1,61 @@
+#ifndef OBELISK_KNOWLEDGE_BASE_H
+#define OBELISK_KNOWLEDGE_BASE_H
+
+#include <sqlite3.h>
+
+#include <iostream>
+#include <string>
+
+namespace obelisk
+{
+    class KnowledgeBase
+    {
+        private:
+            const int DEFAULT_FLAGS
+                = SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;
+            const char* filename_;
+            sqlite3* dbConnection_;
+            int flags_;
+            void logSqliteError(int result);
+
+        public:
+            KnowledgeBase(const char* filename);
+            KnowledgeBase(const char* filename, int flags);
+            ~KnowledgeBase();
+
+            template<typename T, typename U>
+            int addFacts(std::string verb, T leftEntities, U rightEntities);
+            // TODO: add parameter for fact
+            template<typename T, typename U>
+            int addRules(std::string verb, T leftEntities, U rightEntities);
+            template<typename T, typename U> int addActions();
+
+            void getDouble(double* result, float var1, float var2);
+            void getFloat(float* result1, float* result2, double var);
+    };
+
+    class Sql
+    {
+        public:
+            static const std::string create_facts_table;
+    };
+
+    class KnowledgeBaseException : public std::exception
+    {
+        private:
+            std::string errorMessage_;
+
+        public:
+            KnowledgeBaseException(std::string errorMessage) :
+                errorMessage_(errorMessage)
+            {
+            }
+
+            const char* what() const noexcept
+            {
+                return errorMessage_.c_str();
+            }
+    };
+} // namespace obelisk
+
+#endif
--- a/src/lexer.cpp
+++ b/src/lexer.cpp
@ -0,0 +1,121 @@
+#include "lexer.h"
+
+#include <iostream>
+
+int obelisk::Lexer::getToken()
+{
+    static int lastChar = ' ';
+
+    while (isspace(lastChar))
+    {
+        lastChar = getchar();
+    }
+
+    if (isalpha(lastChar))
+    {
+        eraseIdentifier();
+        appendIdentifier(lastChar);
+        while (isalnum((lastChar = getchar())))
+        {
+            appendIdentifier(lastChar);
+        }
+
+        if (getIdentifier() == "def")
+        {
+            return Token::kTokenDef;
+        }
+
+        if (getIdentifier() == "extern")
+        {
+            return kTokenExtern;
+        }
+
+        return kTokenIdentifier;
+    }
+
+    if (isdigit(lastChar) || lastChar == '.')
+    {
+        std::string numberStr;
+        do
+        {
+            numberStr += lastChar;
+            lastChar = getchar();
+        }
+        while (isdigit(lastChar) || lastChar == '.');
+
+        setNumberValue(strtod(numberStr.c_str(), nullptr));
+
+        return kTokenNumber;
+    }
+
+    if (lastChar == '#')
+    {
+        commentLine(&lastChar);
+
+        if (lastChar != EOF)
+        {
+            return getToken();
+        }
+    }
+    else if (lastChar == '/')
+    {
+        lastChar = getchar();
+        if (lastChar == '/')
+        {
+            commentLine(&lastChar);
+
+            if (lastChar != EOF)
+            {
+                return getToken();
+            }
+        }
+    }
+
+    if (lastChar == EOF)
+    {
+        return kTokenEof;
+    }
+
+    int thisChar = lastChar;
+    lastChar     = getchar();
+    return thisChar;
+}
+
+void obelisk::Lexer::commentLine(int* lastChar)
+{
+    do
+    {
+        *lastChar = getchar();
+    }
+    while (*lastChar != EOF && *lastChar != '\n' && *lastChar != '\r');
+}
+
+std::string obelisk::Lexer::getIdentifier()
+{
+    return identifier_;
+}
+
+void obelisk::Lexer::setIdentifier(const std::string identifier)
+{
+    identifier_ = identifier;
+}
+
+void obelisk::Lexer::eraseIdentifier()
+{
+    identifier_ = "";
+}
+
+void obelisk::Lexer::appendIdentifier(int lastChar)
+{
+    identifier_ += lastChar;
+}
+
+double obelisk::Lexer::getNumberValue()
+{
+    return numberValue_;
+}
+
+void obelisk::Lexer::setNumberValue(double numberValue)
+{
+    numberValue_ = numberValue;
+}
--- a/src/lexer.h
+++ b/src/lexer.h
@ -0,0 +1,46 @@
+#ifndef OBELISK_LEXER_H
+#define OBELISK_LEXER_H
+
+#include <string>
+
+namespace obelisk
+{
+
+    class Lexer
+    {
+        private:
+            std::string identifier_;
+            double numberValue_;
+
+            void setIdentifier(const std::string identifier);
+            void eraseIdentifier();
+            void appendIdentifier(int lastChar);
+            void setNumberValue(double numberValue);
+            void commentLine(int* lastChar);
+
+        public:
+            enum Token
+            {
+                kTokenInvalid = -1,
+                kTokenEof     = -2,
+
+                // commands
+                kTokenFact   = -3,
+                kTokenRule   = -4,
+                kTokenDef    = -5,
+                kTokenExtern = -6,
+
+                // primary
+                kTokenIdentifier = -7,
+                kTokenNumber     = -8,
+                kTokenString     = -9
+            };
+
+            int getToken();
+
+            std::string getIdentifier();
+            double getNumberValue();
+    };
+} // namespace obelisk
+
+#endif
--- a/src/meson.build
+++ b/src/meson.build
@ -0,0 +1,17 @@
+obelisk_sources = files(
+    'obelisk.cpp',
+    'lexer.cpp',
+    'parser.cpp',
+    'knowledge_base.cpp'
+)
+
+sqlite3 = dependency('sqlite3')
+
+subdir('ast')
+obelisk_sources += obelisk_ast_sources
+
+executable('obelisk',
+    obelisk_sources,
+    dependencies : [sqlite3],
+    install : true
+)
--- a/src/models/entity.cpp
+++ b/src/models/entity.cpp
@ -0,0 +1,30 @@
+#include "models/entity.h"
+
+obelisk::Entity::Entity()
+{
+}
+
+obelisk::Entity::Entity(std::string name)
+{
+    name = name;
+}
+
+int obelisk::Entity::getId()
+{
+    return id_;
+}
+
+void obelisk::Entity::setId(int id)
+{
+    id_ = id;
+}
+
+std::string obelisk::Entity::getName()
+{
+    return name_;
+}
+
+void obelisk::Entity::setName(std::string name)
+{
+    name_ = name_;
+}
--- a/src/models/entity.h
+++ b/src/models/entity.h
@ -0,0 +1,26 @@
+#ifndef OBELISK_MODELS_ENTITY_H
+#define OBELISK_MODELS_ENTITY_H
+
+#include <string>
+
+namespace obelisk
+{
+    class Entity
+    {
+        private:
+            int id_;
+            std::string name_;
+
+        public:
+            Entity();
+            Entity(std::string name);
+
+            int getId();
+            void setId(int id);
+
+            std::string getName();
+            void setName(std::string name);
+    };
+} // namespace obelisk
+
+#endif
--- a/src/models/verb.cpp
+++ b/src/models/verb.cpp
@ -0,0 +1,36 @@
+#include "models/verb.h"
+
+obelisk::Verb::Verb()
+{
+}
+
+obelisk::Verb::Verb(std::string verb)
+{
+    verb_ = verb;
+}
+
+obelisk::Verb::Verb(int id, std::string verb)
+{
+    id_   = id;
+    verb_ = verb;
+}
+
+int obelisk::Verb::getId()
+{
+    return id_;
+}
+
+void obelisk::Verb::setId(int id)
+{
+    id_ = id;
+}
+
+std::string obelisk::Verb::getVerb()
+{
+    return verb_;
+}
+
+void obelisk::Verb::setVerb(std::string verb)
+{
+    verb_ = verb;
+}
--- a/src/models/verb.h
+++ b/src/models/verb.h
@ -0,0 +1,27 @@
+#ifndef OBELISK_MODELS_VERB_H
+#define OBELISK_MODELS_VERB_H
+
+#include <string>
+
+namespace obelisk
+{
+    class Verb
+    {
+        private:
+            int id_;
+            std::string verb_;
+
+        public:
+            Verb();
+            Verb(std::string verb);
+            Verb(int id, std::string verb);
+
+            int getId();
+            void setId(int id);
+
+            std::string getVerb();
+            void setVerb(std::string verb);
+    };
+} // namespace obelisk
+
+#endif
--- a/src/obelisk.cpp
+++ b/src/obelisk.cpp
@ -0,0 +1,90 @@
+#include "knowledge_base.h"
+#include "lexer.h"
+#include "obelisk.h"
+#include "parser.h"
+
+#include <iomanip>
+#include <iostream>
+#include <limits>
+
+static void mainLoop()
+{
+    obelisk::Parser* parser = new obelisk::Parser();
+
+    // Prime the first token.
+    fprintf(stderr, "ready> ");
+    parser->getNextToken();
+
+    while (true)
+    {
+        fprintf(stderr, "ready> ");
+        switch (parser->getCurrentToken())
+        {
+            case obelisk::Lexer::kTokenEof :
+                return;
+            case obelisk::Lexer::kTokenInvalid :
+                std::cerr << "Invalid token!\n";
+                parser->getNextToken();
+                return;
+            case ';' : // ignore top-level semicolons.
+                std::cout << "Identifier: "
+                          << parser->getLexer()->getIdentifier() << std::endl;
+                std::cout << "Num: " << parser->getLexer()->getNumberValue()
+                          << std::endl;
+                parser->getNextToken();
+                break;
+            default :
+                parser->getNextToken();
+                break;
+        }
+    }
+}
+
+int main(int argc, char** argv)
+{
+    for (int i = 1; i < argc; i++)
+    {
+        std::cout << argv[i] << std::endl;
+    }
+
+    try
+    {
+        obelisk::KnowledgeBase* kb = new obelisk::KnowledgeBase("cromer.kb");
+
+        /*std::vector<std::string> leftObjects;
+        std::vector<std::string> rightObjects;
+        leftObjects.push_back("chris");
+        leftObjects.push_back("martin");
+
+        rightObjects.push_back("happy");
+        rightObjects.push_back("smart");
+
+        kb->addFacts("is", leftObjects, rightObjects);*/
+    }
+    catch (obelisk::KnowledgeBaseException& exception)
+    {
+        std::cout << exception.what() << std::endl;
+        return EXIT_FAILURE;
+    }
+
+    // This can be used to store a double as 2 floats in the database, then restore it back to a double.
+    // Inspired by Godot's double precision on the GPU to render large worlds.
+    /*float first;
+    float second;
+    double var = 0.123456789012345;
+    kb->getFloat(&first, &second, var);
+    std::cout << std::setprecision(std::numeric_limits<double>::digits10)
+              << "Double: " << var << std::endl
+              << "First: " << first << std::endl
+              << "Second: " << second << std::endl;
+    var = 0.0;
+    kb->getDouble(&var, first, second);
+    std::cout << std::setprecision(std::numeric_limits<double>::digits10)
+              << "Double: " << var << std::endl
+              << "First: " << first << std::endl
+              << "Second: " << second << std::endl;*/
+
+    mainLoop();
+
+    return EXIT_SUCCESS;
+}
--- a/src/obelisk.h
+++ b/src/obelisk.h
@ -0,0 +1 @@
+static void mainLoop();
--- a/src/parser.cpp
+++ b/src/parser.cpp
@ -0,0 +1,225 @@
+#include "ast/call_expression_ast.h"
+#include "ast/number_expression_ast.h"
+#include "ast/variable_expression_ast.h"
+#include "parser.h"
+
+obelisk::Parser::Parser()
+{
+    lexer_ = new obelisk::Lexer();
+}
+
+obelisk::Parser::Parser(obelisk::Lexer* lexer)
+{
+    if (lexer != nullptr)
+    {
+        lexer_ = lexer;
+    }
+    else
+    {
+        Parser();
+    }
+}
+
+obelisk::Parser::~Parser()
+{
+    delete lexer_;
+}
+
+obelisk::Lexer* obelisk::Parser::getLexer()
+{
+    return lexer_;
+}
+
+int obelisk::Parser::getNextToken()
+{
+    setCurrentToken(getLexer()->getToken());
+    return getCurrentToken();
+}
+
+int obelisk::Parser::getCurrentToken()
+{
+    return currentToken_;
+}
+
+void obelisk::Parser::setCurrentToken(int currentToken)
+{
+    currentToken_ = currentToken;
+}
+
+std::unique_ptr<obelisk::ExpressionAST> obelisk::Parser::logError(
+    const char* str)
+{
+    fprintf(stderr, "Error: %s\n", str);
+    return nullptr;
+}
+
+std::unique_ptr<obelisk::PrototypeAST> obelisk::Parser::logErrorPrototype(
+    const char* str)
+{
+    logError(str);
+    return nullptr;
+}
+
+std::unique_ptr<obelisk::ExpressionAST> obelisk::Parser::parseExpression()
+{
+    auto LHS = parsePrimary();
+    if (!LHS)
+    {
+        return nullptr;
+    }
+
+    return LHS;
+}
+
+std::unique_ptr<obelisk::ExpressionAST> obelisk::Parser::parsePrimary()
+{
+    switch (getCurrentToken())
+    {
+        case obelisk::Lexer::kTokenIdentifier :
+            return parseIdentifierExpression();
+        case obelisk::Lexer::kTokenNumber :
+            return parseNumberExpression();
+        case '(' :
+            return parseParenthesisExpression();
+        default :
+            return logError("unknown token when expecting and expression");
+    }
+}
+
+std::unique_ptr<obelisk::ExpressionAST> obelisk::Parser::parseNumberExpression()
+{
+    auto result = std::make_unique<obelisk::NumberExpressionAST>(
+        getLexer()->getNumberValue());
+    getNextToken();
+    return std::move(result);
+}
+
+std::unique_ptr<obelisk::ExpressionAST>
+    obelisk::Parser::parseParenthesisExpression()
+{
+    getNextToken();
+    auto v = parseExpression();
+    if (!v)
+    {
+        return nullptr;
+    }
+
+    if (getCurrentToken() != ')')
+    {
+        return logError("expected ')'");
+    }
+    getNextToken();
+    return v;
+}
+
+std::unique_ptr<obelisk::ExpressionAST>
+    obelisk::Parser::parseIdentifierExpression()
+{
+    std::string idName = getLexer()->getIdentifier();
+    getNextToken();
+    if (getCurrentToken() != '(')
+    {
+        return std::make_unique<obelisk::VariableExpressionAST>(idName);
+    }
+
+    getNextToken();
+    std::vector<std::unique_ptr<obelisk::ExpressionAST>> args;
+    if (getCurrentToken() != ')')
+    {
+        while (true)
+        {
+            if (auto arg = parseExpression())
+            {
+                args.push_back(std::move(arg));
+            }
+            else
+            {
+                return nullptr;
+            }
+
+            if (getCurrentToken() == ')')
+            {
+                break;
+            }
+
+            if (getCurrentToken() != ',')
+            {
+                return logError("Expected ')' or ',' in argument list");
+            }
+
+            getNextToken();
+        }
+    }
+
+    getNextToken();
+    return std::make_unique<CallExpressionAST>(idName, std::move(args));
+}
+
+std::unique_ptr<obelisk::PrototypeAST> obelisk::Parser::parsePrototype()
+{
+    if (getCurrentToken() != obelisk::Lexer::kTokenIdentifier)
+    {
+        return logErrorPrototype("Expected function name in prototype");
+    }
+
+    std::string functionName = getLexer()->getIdentifier();
+    getNextToken();
+
+    if (getCurrentToken() != '(')
+    {
+        return logErrorPrototype("Expected '(' in prototype");
+    }
+
+    std::vector<std::string> argNames;
+    while (getNextToken() == obelisk::Lexer::kTokenIdentifier)
+    {
+        argNames.push_back(getLexer()->getIdentifier());
+    }
+
+    if (getCurrentToken() != ')')
+    {
+        return logErrorPrototype("Expected ')' in prototype");
+    }
+
+    getNextToken();
+
+    return std::make_unique<obelisk::PrototypeAST>(functionName,
+        std::move(argNames));
+}
+
+std::unique_ptr<obelisk::FunctionAST> obelisk::Parser::parseDefinition()
+{
+    getNextToken();
+    auto prototype = parsePrototype();
+    if (!prototype)
+    {
+        return nullptr;
+    }
+
+    if (auto expression = parseExpression())
+    {
+        return std::make_unique<FunctionAST>(std::move(prototype),
+            std::move(expression));
+    }
+
+    return nullptr;
+}
+
+std::unique_ptr<obelisk::FunctionAST> obelisk::Parser::parseTopLevelExpression()
+{
+    if (auto expression = parseExpression())
+    {
+        // Make an anonymous prototype
+        auto prototype = std::make_unique<obelisk::PrototypeAST>("__anon_expr",
+            std::vector<std::string>());
+        return std::make_unique<obelisk::FunctionAST>(std::move(prototype),
+            std::move(expression));
+    }
+    return nullptr;
+}
+
+std::unique_ptr<obelisk::PrototypeAST> obelisk::Parser::parseExtern()
+{
+    getNextToken();
+    return parsePrototype();
+}
--- a/src/parser.h
+++ b/src/parser.h
@ -0,0 +1,53 @@
+#ifndef OBELISK_PARSER_H
+#define OBELISK_PARSER_H
+
+#include "ast/expression_ast.h"
+#include "ast/function_ast.h"
+#include "ast/prototype_ast.h"
+#include "lexer.h"
+
+#include <memory>
+
+namespace obelisk
+{
+    class Parser
+    {
+        private:
+            obelisk::Lexer* lexer_;
+            int currentToken_;
+
+            void setCurrentToken(int currentToken);
+
+            std::unique_ptr<obelisk::ExpressionAST> logError(const char* str);
+            std::unique_ptr<obelisk::PrototypeAST> logErrorPrototype(
+                const char* str);
+
+            std::unique_ptr<obelisk::ExpressionAST> parseExpression();
+            std::unique_ptr<obelisk::ExpressionAST> parseNumberExpression();
+            std::unique_ptr<obelisk::ExpressionAST>
+                parseParenthesisExpression();
+            std::unique_ptr<obelisk::ExpressionAST> parseIdentifierExpression();
+            std::unique_ptr<obelisk::ExpressionAST> parsePrimary();
+            std::unique_ptr<obelisk::PrototypeAST> parsePrototype();
+            std::unique_ptr<obelisk::FunctionAST> parseDefinition();
+            std::unique_ptr<obelisk::FunctionAST> parseTopLevelExpression();
+            std::unique_ptr<obelisk::PrototypeAST> parseExtern();
+
+        public:
+            Parser();
+            Parser(obelisk::Lexer* lexer);
+            ~Parser();
+
+            obelisk::Lexer* getLexer();
+
+            int getCurrentToken();
+
+            int getNextToken();
+
+            void handleDefinition();
+            void handleExtern();
+            void handleTopLevelExpression();
+    };
+} // namespace obelisk
+
+#endif