Bump version.

Also updated some grammar rules for negatives to be more general.

.clang-format

@@ -0,0 +1,13 @@
+---
+AlignConsecutiveShortCaseStatements:
+  Enabled: true
+  AcrossEmptyLines: true
+  AcrossComments: true
+IndentCaseLabels: true
+AllowShortBlocksOnASingleLine: Always
+AllowShortCaseLabelsOnASingleLine: true
+AllowShortIfStatementsOnASingleLine: AllIfsAndElse
+AllowShortLoopsOnASingleLine: true
+IndentWidth: 4
+PointerAlignment: Left
+AlignAfterOpenBracket: BlockIndent

.clangd

@@ -0,0 +1,2 @@
+CompileFlags:
+  Add: [-xc]

.gitignore

@@ -1,6 +1,8 @@
 *.o
 *.so
+tags
 *.out
-obj/
-compile_commands.json
 .cache
+build/*
+compile_commands.json
+vgcore.*

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "test/Unity"]
+	path = test/Unity
+	url = https://github.com/ThrowTheSwitch/Unity

Makefile

@@ -1,29 +1,105 @@
 NAME = scl
 
-CC = clang
+TARGET = $(NAME).out
-CFLAGS = -Wall --std=c11
-LDFLAGS = 
 
 SRC_DIR = src
-OBJ_DIR = obj
+INC_DIR = $(SRC_DIR)/include
-TARGET = $(NAME).out
+BUILD_DIR = build
+OBJ_DIR = $(BUILD_DIR)/obj
+GRAM_DIR = $(BUILD_DIR)/grammars
+TEST_DIR = test
+TEST_BUILD_DIR = $(BUILD_DIR)/test
+TEST_OBJ_DIR = $(TEST_BUILD_DIR)/obj
+
+CC = clang
+LINK = clang
+CFLAGS = -Wall -DDBG -ggdb
+LDFLAGS = -lm
+BATS = bats
+BISON = bison
+PRINT = echo -e
 
 SRC_FILES = $(wildcard $(SRC_DIR)/*.c)
 OBJ_FILES = $(patsubst $(SRC_DIR)/%.c, $(OBJ_DIR)/%.o, $(SRC_FILES))
+OBJ_FILES_NOMAIN = $(filter-out $(OBJ_DIR)/main.o, $(OBJ_FILES)) # Object files without main.c.
+GRAM_FILES = $(GRAM_DIR)/grammar.tab.c $(GRAM_DIR)/grammar.tab.h
+UNITY_DIR = $(TEST_DIR)/Unity
+UNITY_C = $(UNITY_DIR)/src/unity.c
+UNITY_H = $(UNITY_DIR)/src/unity.h
+UNITY_OBJ = $(TEST_BUILD_DIR)/unity.o
+TEST_SRC_FILES = $(wildcard $(TEST_DIR)/*.c)
+TEST_OBJ_FILES = $(patsubst $(TEST_DIR)/%.c, $(TEST_OBJ_DIR)/%.o, $(TEST_SRC_FILES))
+TEST_BIN_FILES = $(patsubst $(TEST_DIR)/%.c, $(TEST_BUILD_DIR)/%.out, $(TEST_SRC_FILES))
+TEST_VAL_DIR = $(TEST_DIR)/validation
+
+RESETCOLOR = \033[0m
+WHITE = $(RESETCOLOR)\033[37m
+WHITE_BOLD = $(RESETCOLOR)\033[37;1m
 
 all: $(TARGET)
 
-$(TARGET): $(OBJ_FILES)
+release: clean
-	@ echo -e "\x1b[32;1mLinking \x1b[0m\x1b[32m$(TARGET)\x1b[32;1m...\x1b[0m\x1b[37m $(CC) -o $(TARGET) $(OBJ_FILES) $(LDFLAGS)\x1b[0m"
+release: CFLAGS = -Wall -O2
-	@ $(CC) -o $(TARGET) $(OBJ_FILES) $(LDFLAGS)
+release: $(TARGET)
 
-$(OBJ_DIR)/%.o: $(SRC_DIR)/%.c $(SRC_DIR)/include/%.h
+# Run the target.
+run: $(TARGET)
+	./$(TARGET)
+
+# Generate grammars with bison.
+$(GRAM_FILES): $(SRC_DIR)/grammar.y
+	@ mkdir -p $(GRAM_DIR)
+	@ $(PRINT) "$(WHITE_BOLD)Generating grammars...$(RESETCOLOR)"
+	$(BISON) $< -o$(GRAM_DIR)/grammar.tab.c -H$(GRAM_DIR)/grammar.tab.h
+
+# Compile grammars.
+$(OBJ_DIR)/grammar.o: $(GRAM_DIR)/grammar.tab.c $(GRAM_DIR)/grammar.tab.h $(OBJ_DIR)/lexer.o
+	@ $(PRINT) "$(WHITE_BOLD)Compiling grammars...$(RESETCOLOR)"
+	$(CC) $(CFLAGS) -c $< -o $@
+
+# Lexer depends on grammars.
+$(OBJ_DIR)/lexer.o: $(SRC_DIR)/lexer.c $(GRAM_FILES)
 	@ mkdir -p $(OBJ_DIR)
-	@ echo -e "\x1b[32;1mCompiling \x1b[0m\x1b[32m$<\x1b[32;1m... \x1b[0m\x1b[37m$(CC) $(CFLAGS) -c $< -o $@\x1b[0m"
+	@ $(PRINT) "$(WHITE_BOLD)Compiling source object $(WHITE)$@$(WHITE_BOLD)... $(RESETCOLOR)"
-	@ $(CC) $(CFLAGS) -c $< -o $@
+	$(CC) $(CFLAGS) -c $< -o $@
+
+# Compile project source objects.
+$(OBJ_DIR)/%.o: $(SRC_DIR)/%.c $(INC_DIR)/%.h
+	@ mkdir -p $(OBJ_DIR)
+	@ $(PRINT) "$(WHITE_BOLD)Compiling source object $(WHITE)$@$(WHITE_BOLD)... $(RESETCOLOR)"
+	$(CC) $(CFLAGS) -c $< -o $@
+
+# Link to final binary.
+$(TARGET): $(OBJ_DIR)/grammar.o $(OBJ_FILES)
+	@ $(PRINT) "$(WHITE_BOLD)Linking $(WHITE)$@$(WHITE_BOLD)...$(RESETCOLOR)"
+	$(LINK) -o $(TARGET) $(OBJ_FILES) $(OBJ_DIR)/grammar.o $(LDFLAGS)
+
+# Compile Unity object.
+$(UNITY_OBJ): $(UNITY_C) $(UNITY_H)
+	@ $(PRINT) "$(WHITE_BOLD)Compiling Unity...$(RESETCOLOR)"
+	$(CC) $(CFLAGS) -D UNITY_OUTPUT_COLOR -c $< -o $@
+
+# Compile test object.
+$(TEST_OBJ_DIR)/test_%.o: $(TEST_DIR)/test_%.c
+	@ $(PRINT) "$(WHITE_BOLD)Compiling test object $(WHITE)$@$(WHITE_BOLD)...$(RESETCOLOR)"
+	$(CC) $(CFLAGS) -c $< -o $@
+
+# Link final test binary.
+$(TEST_BUILD_DIR)/test_%.out: $(TEST_OBJ_DIR)/test_%.o $(OBJ_DIR)/%.o $(UNITY_OBJ)
+	@ $(PRINT) "$(WHITE_BOLD)Linking test binary $(WHITE)$@$(WHITE_BOLD)...$(RESETCOLOR)"
+	$(LINK) -o $@ $? $(LDFLAGS)
+
+# Run the test files.
+test: $(TARGET) $(TEST_BIN_FILES)
+	@ $(PRINT) "$(WHITE_BOLD)Running unit tests...$(RESETCOLOR)"
+	for test in $(TEST_BIN_FILES); do ./$${test}; done
+	@ $(PRINT) "$(WHITE_BOLD)Running validation tests...$(RESETCOLOR)"
+	$(BATS) $(TEST_VAL_DIR)
+
 
 clean:
-	@ echo -e "\x1b[32;1mCleaning up...\x1b[0m"
+	@ $(PRINT) "$(WHITE_BOLD)Cleaning up...$(RESETCOLOR)"
-	@ rm -rf $(OBJ_DIR) $(TARGET)
+	rm -rf $(OBJ_DIR)/*.o $(TEST_OBJ_DIR)/*.o $(TEST_BUILD_DIR)/test.out $(TARGET) $(GRAM_DIR)/* $(UNITY_OBJ)
 
-.PHONY: all clean
+.PHONY: all clean test nocolor release run
+.PRECIOUS: $(TEST_OBJ_FILES)

README.md

@@ -1 +1,62 @@
-# SCL: Simple Calculator Language
+# SCL: Simple CAS Language
+
+Version v1.0-alpha
+
+## Usage
+
+```bash
+git clone https://git.signorovitch.org/jacob/scl && cd scl
+make release    # Build.
+./scl           # Run.
+```
+
+If you wish to run tests, make sure to run `git clone --recurse-submodules` to
+include the [Unity](https://github.com/ThrowTheSwitch/Unity) test framework.
+
+## Current State
+
+See [STATUS.md](STATUS.md). Currently, one is able to use `scl` as a basic,
+interactive, four-function calculator.
+
+## Syntax (Planned)
+
+As one would expect, you can evaluate simple infix expressions:
+
+```scl
+> 1 + 1
+= 2
+```
+
+You can also define your own functions:
+
+```scl
+> f(x) = 2x
+> f(2)
+= 4
+```
+
+Symbolic algebra is done in the following manner:
+
+```scl
+> f(x) = x^4
+> diff(f, x:sym, 2)
+= 12x^2
+```
+
+SCL will dynamically decide on types, but you can state them explicitly as
+well:
+
+```scl
+> f(x:int) = 2x
+> f(2.2)
+! f(x:int): x must be of type int.
+```
+
+Variables can be defined, with several attributes:
+
+```scl
+> a = 1             // Interpret type automatically.
+> b:int = 1         // Must be int.
+> c:const:int = 1   // Constant: value can never change.
+> x:sym             // Treated symbolicaly.
+```

STATUS.md

@@ -0,0 +1,55 @@
+# SCL Design Status
+
+- [x] Data definitions
+  - [x] Token Definitions
+  - [x] AST Definitions
+
+- [ ] Parser
+  - [x] Parse numbers
+  - [x] Parse floats
+  - [x] Parse negative numbers
+  - [x] Parse infix operators
+  - [x] Order of operations
+  - [x] Parse function application
+  - [x] Parse order of operations with parenthesis
+  - [ ] Parse variable invocation
+  - [ ] Parse variable definition
+    - [ ] Parse types
+  - [ ] Parse function definition
+  - [ ] Parse lists/arrays/vectors
+  - [ ] Parse blocks
+  - [ ] Parse control flow
+    - [ ] Parse `if` statements
+    - [ ] Parse `loop`s
+    - [ ] Parse `for` loops
+    - [ ] Parse `while` loops
+    - [ ] Parse `case` statements
+    - [ ] Parse `goto` statements
+  - [ ] Parse lambda function definition
+  - [ ] Parse function calling with positional arguments
+  - [ ] Parse variadic functions
+  - [ ] Parse infix function definition
+
+- [ ] Executer
+  - [x] Exec function calls
+  - [ ] Exec variable use
+  - [ ] Exec variable definition
+  - [ ] Exec function definition
+  - [ ] Exec symbolic variables
+  - [ ] Exec control flow statements
+  - [ ] Exec variadic functions
+  - [ ] Exec lambda functions
+  - [ ] Exec lists
+  - [ ] Exec arrays
+  - [ ] Exec vectors
+
+- [ ] Interface
+  - [ ] Interactive interpreter
+    - [ ] Use GNU readline
+    - [ ] Multi-line input
+    - [ ] Syntax highlighting
+    - [ ] Autocompletion/suggestion
+  - [ ] Command line interface
+    - [ ] Pass in a file
+    - [ ] Save AST to a file
+    - [ ] Run from AST file

examples/test.scl

@@ -0,0 +1 @@
+1 + 1

src/ast.c

@@ -0,0 +1,117 @@
+#include <stdio.h>
+
+#include "include/ast.h"
+#include "include/dstr.h"
+#include "include/util.h"
+
+extern AST* root;
+
+static char* asttype_names[] = {
+    [AST_TYPE_CALL] = "FUNC CALL",
+    [AST_TYPE_NUM] = "NUMBER",
+    [AST_TYPE_VREF] = "VAR REFERENCE"
+};
+
+AST* ast_init(ASTType type, void* data) {
+    AST* ast = malloc(sizeof(AST));
+
+    ast->type = type;
+    ast->data = data;
+
+    return ast;
+}
+
+void ast_destroy(AST* ast) {
+    if (!ast) return;
+
+    switch (ast->type) {
+        case AST_TYPE_NUM:  ast_num_data_destroy(ast->data); break;
+        case AST_TYPE_CALL: ast_call_data_destroy(ast->data); break;
+        default:
+            log_dbgf("Unknown ast type %d (max: %d)", ast->type, AST_TYPE_MAX);
+    }
+
+    free(ast);
+}
+
+void ast_print(AST* ast) { ast_print_i(ast, 0); }
+
+void ast_print_i(AST* ast, int i) {
+    INDENT_BEGIN(i);
+
+    INDENT_TITLE("AST", ast);
+    INDENT_FIELD("type", "%s", asttype_names[ast->type]);
+    INDENT_FIELD_EXT_NONL_START("data");
+    switch (ast->type) {
+        case AST_TYPE_NUM:
+            printf("%s  %lf\n", INDENT_spacing->buf, *(ASTNumData*)ast->data);
+            break;
+        case AST_TYPE_CALL: ast_call_print(ast->data, i + 2); break;
+        case AST_TYPE_VREF: ast_vref_print(ast->data, i + 2); break;
+        default:            exit(1);
+    }
+    INDENT_FIELD_NONL_END;
+    INDENT_END;
+}
+
+ASTNumData* ast_num_data_init(double val) {
+    talloc(ASTNumData, num);
+
+    *num = val;
+
+    return num;
+}
+
+void ast_num_data_destroy(ASTNumData* num) { free(num); }
+
+void ast_num_print(ASTNumData* data, int i) {
+    INDENT_BEGIN(i);
+
+    INDENT_FIELD("data", "%lf", *data);
+
+    INDENT_END;
+}
+
+ASTCallData* ast_call_data_init(char* to, size_t argc, AST** argv) {
+    talloc(ASTCallData, call);
+
+    log_dbgf("to: %s", to);
+
+    call->to = to;
+    call->argc = argc;
+    call->argv = argv;
+
+    return call;
+}
+
+void ast_call_data_destroy(ASTCallData* call) {
+    if (!call) return;
+    free(call->to);
+    for (size_t i = 0; i < call->argc; i++) ast_destroy(call->argv[i]);
+    free(call->argv);
+    free(call);
+}
+
+void ast_call_print(ASTCallData* data, int i) {
+    INDENT_BEGIN(i);
+
+    INDENT_TITLE("ASTCallData", data);
+    INDENT_FIELD("to", "%s", data->to);
+    INDENT_FIELD("argc", "%ld", data->argc);
+    INDENT_FIELD_LIST("argv", data->argv, data->argc, ast_print_i);
+
+    INDENT_END;
+}
+
+ASTVrefData* ast_vref_data_init(char* to) {}
+
+void ast_vref_data_destroy(ASTVrefData* vref) {}
+
+void ast_vref_print(ASTVrefData* data, int i) {
+    INDENT_BEGIN(i);
+
+    INDENT_TITLE("ASTVrefData", data);
+    INDENT_FIELD("to", "%s", data->to);
+
+    INDENT_END;
+}

src/dstr.c

@@ -0,0 +1,54 @@
+#include "include/dstr.h"
+#include "include/util.h"
+
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+
+Dstr* dstr_init(void) {
+    Dstr* dstr = malloc(sizeof(Dstr));
+
+    dstr->sz = DSTR_INITSZ;
+    dstr->buf = malloc(DSTR_INITSZ);
+    *dstr->buf = '\0';
+    dstr->ln = 0;
+
+    return dstr;
+}
+
+void dstr_destroy(Dstr* dstr) {
+    free(dstr->buf);
+    free(dstr);
+}
+
+void dstr_destroypsv(Dstr* dstr) { free(dstr); }
+
+// Check whether the buffer is overflowing and resize it if necessary.
+void check_resz(Dstr* dstr, size_t ln) {
+    while (dstr->ln + ln + 1 > dstr->sz) {
+        // Double the buffer size when overflown.
+        dstr->sz *= 2;
+        dstr->buf = realloc(dstr->buf, dstr->sz);
+        log_dbgf(
+            "dstr @ %p doubled from %ld to %ld", dstr, dstr->sz / 2, dstr->sz
+        );
+    }
+}
+
+void dstr_append(Dstr* dest, char* src, size_t ln) {
+    check_resz(dest, ln);
+
+    // Overwrites the \0 at the end of the string, keeps the null from the given
+    // string.
+    memcpy(dest->buf + dest->ln, src, ln + 1);
+    dest->ln += ln;
+}
+
+void dstr_appendch(Dstr* dest, char ch) {
+    check_resz(dest, 1);
+
+    // Overwrites the preexisting null terminator, and adds one of its own.
+    dest->buf[dest->ln] = ch;
+    dest->buf[dest->ln + 1] = '\0';
+    dest->ln += 1;
+}

src/exec.c

@@ -0,0 +1,70 @@
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "include/ast.h"
+#include "include/exec.h"
+#include "include/util.h"
+
+extern AST* root;
+
+ASTNumData exec_exp(AST* ast) {
+    log_dbg("Started execution.");
+    switch (ast->type) {
+        case AST_TYPE_CALL: return exec_call(ast);
+        case AST_TYPE_NUM:  return *(ASTNumData*)ast->data;
+        default:            printf("what\n");
+                            exit(1);
+    }
+}
+
+ASTNumData exec_call(AST* ast) {
+    log_dbg("Started call execution.");
+    fflush(stdout);
+    ASTCallData* calldata = (ASTCallData*)ast->data;
+    if (calldata->argc >= 1) {
+    if (!strcmp(calldata->to, "sum")) {
+        double total = exec_exp(calldata->argv[0]);
+
+        for (
+            size_t i = 1;
+            i < calldata->argc;
+            total += exec_exp(calldata->argv[i++])
+        );
+
+        return total;
+    } else if (!strcmp(calldata->to, "sub")) {
+        double total = exec_exp(calldata->argv[0]);
+
+        for (
+            size_t i = 1;
+            i < calldata->argc;
+            total -= exec_exp(calldata->argv[i++])
+        );
+
+        return total;
+    } else if (!strcmp(calldata->to, "mul")) {
+        double total = exec_exp(calldata->argv[0]);
+
+        for (
+            size_t i = 1;
+            i < calldata->argc;
+            total *= exec_exp(calldata->argv[i++])
+        );
+
+        return total;
+    } else if (!strcmp(calldata->to, "div")) {
+        double total = exec_exp(calldata->argv[0]);
+
+        for (
+            size_t i = 1;
+            i < calldata->argc;
+            total /= exec_exp(calldata->argv[i++])
+        );
+
+        return total;
+    }}
+    return -1000;
+}
+
+void exec_print(double n) { printf("= %lf\n", n); }

src/grammar.y

@@ -0,0 +1,131 @@
+%{
+    #include <string.h>
+    #include <stdio.h>
+    #include "../../src/include/ast.h"
+    #include "../../src/include/lexer.h"
+
+    int yylex(void);
+    void yyerror(char const*);
+
+    AST* root = NULL;
+%}
+
+%code requires {
+    #include "../../src/include/ast.h"
+}
+
+%union {
+    double fval;
+    char* strval;
+    AST* ast;
+    ArgArr* argarr;
+}
+
+%define parse.error verbose
+
+%token LGROUP
+%token RGROUP
+%token SEP
+
+%token<strval> WORD
+%token<fval> NUM
+
+%token SUB
+%token PLUS
+%token MULT
+%token DIV
+
+%token NL
+
+%left PLUS SUB
+%left MULT DIV
+%precedence NEG
+
+%type<ast> exp;
+%type<argarr> arg;
+%type<argarr> argstart;
+
+%%
+
+input:
+    %empty
+    | exp { root = $1; }
+    ;
+
+
+argstart:
+    exp {
+        ArgArr* argarr = argarr_init();
+        argarr_add(argarr, $1);
+        $$ = argarr;
+    }
+    ;
+
+arg:
+    argstart { $$ = $1; }
+    | arg SEP exp {
+        argarr_add($1, $3);
+        $$ = $1;
+    }
+    ;
+
+exp:
+    NUM { $$ = ast_init(AST_TYPE_NUM, ast_num_data_init($1)); }
+
+    | SUB exp {
+        AST** argv = calloc(2, sizeof(AST*));
+        argv[0] = ast_init(AST_TYPE_NUM, ast_num_data_init(-1));
+        argv[1] = $2;
+        char* to = malloc(4);
+        strcpy(to, "mul");
+        $$ = ast_init(AST_TYPE_CALL, ast_call_data_init(to, 2, argv));
+    }
+
+    | LGROUP exp RGROUP { $$ = $2; }
+
+    // Variable reference.
+    //| WORD
+
+    | WORD LGROUP arg RGROUP {
+        size_t argc = $3->ln;
+        AST** argv = $3->buf;
+        argarr_destroypsv($3);
+        $$ = ast_init(AST_TYPE_CALL, ast_call_data_init($1, argc, argv));
+    }
+
+    | exp PLUS exp {
+        AST** argv = calloc(2, sizeof(AST*));
+        argv[0] = $1;
+        argv[1] = $3;
+        char* to = malloc(4);
+        strcpy(to, "sum");
+        $$ = ast_init(AST_TYPE_CALL, ast_call_data_init(to, 2, argv));
+    }
+
+    | exp SUB exp {
+        AST** argv = calloc(2, sizeof(AST*));
+        argv[0] = $1;
+        argv[1] = $3;
+        char* to = malloc(4);
+        strcpy(to, "sub");
+        $$ = ast_init(AST_TYPE_CALL, ast_call_data_init(to, 2, argv));
+    }
+
+    | exp MULT exp {
+        AST** argv = calloc(2, sizeof(AST*));
+        argv[0] = $1;
+        argv[1] = $3;
+        char* to = malloc(4);
+        strcpy(to, "mul");
+        $$ = ast_init(AST_TYPE_CALL, ast_call_data_init(to, 2, argv));
+    }
+
+    | exp DIV exp {
+        AST** argv = calloc(2, sizeof(AST*));
+        argv[0] = $1;
+        argv[1] = $3;
+        char* to = malloc(4);
+        strcpy(to, "div");
+        $$ = ast_init(AST_TYPE_CALL, ast_call_data_init(to, 2, argv));
+    }
+%%

src/include/ast.h

@@ -0,0 +1,47 @@
+#ifndef AST_H
+#define AST_H
+
+#include <stdlib.h>
+
+typedef enum {
+    AST_TYPE_NUM,  // A number.
+    AST_TYPE_CALL, // A function call.
+    AST_TYPE_VREF, // A variable reference.
+    AST_TYPE_MAX = AST_TYPE_CALL
+} ASTType;
+
+typedef struct {
+    ASTType type;
+    void* data;
+} AST;
+
+AST* ast_init(ASTType type, void* data);
+void ast_destroy(AST* ast);
+void ast_print(AST* ast);
+void ast_print_i(AST* ast, int i);
+
+typedef double ASTNumData;
+
+ASTNumData* ast_num_data_init(double val);
+void ast_num_data_destroy(ASTNumData* num);
+void ast_num_print(ASTNumData*, int i);
+
+typedef struct {
+    char* to;    // What the call's to.
+    size_t argc; // Argument count.
+    AST** argv;  // Argument vector.
+} ASTCallData;
+
+ASTCallData* ast_call_data_init(char* to, size_t argc, AST** argv);
+void ast_call_data_destroy(ASTCallData* call);
+void ast_call_print(ASTCallData*, int i);
+
+typedef struct {
+    char* to; // What the reference's to.
+} ASTVrefData;
+
+ASTVrefData* ast_vref_data_init(char* to);
+void ast_vref_data_destroy(ASTVrefData* call);
+void ast_vref_print(ASTVrefData*, int i);
+
+#endif

src/include/dstr.h

@@ -0,0 +1,25 @@
+#ifndef DSTR_H
+#define DSTR_H
+
+#include <stdlib.h>
+
+#define DSTR_INITSZ 2
+
+typedef struct {
+    char* buf; // The buffer containing the string.
+    size_t sz; // The size of the buffer.
+    size_t ln; // The number of characters in the buffer.
+} Dstr;
+
+Dstr* dstr_init(void);
+void dstr_destroy(Dstr* dstr);
+// Destroy Dstr structure but preserve ->buf.
+void dstr_destroypsv(Dstr* dstr);
+
+// Append ln characters of src to dest.
+void dstr_append(Dstr* dest, char* src, size_t ln);
+
+// Append ch to dest.
+void dstr_appendch(Dstr* dest, char ch);
+
+#endif

src/include/exec.h

@@ -0,0 +1,10 @@
+#ifndef EXEC_H
+#define EXEC_H
+
+#include "ast.h"
+
+ASTNumData exec_exp(AST* ast);
+ASTNumData exec_call(AST* ast);
+void exec_print(double n);
+
+#endif

src/include/lexer.h

@@ -0,0 +1,39 @@
+#ifndef LEXER_H
+#define LEXER_H
+
+#include <assert.h>
+#include <stddef.h>
+
+#include "ast.h"
+
+#define ARLN 8
+
+extern char* inp;
+
+typedef struct {
+    size_t sz;
+    size_t ln;
+    AST** buf;
+} ArgArr;
+
+ArgArr* argarr_init();
+void argarr_destroy(ArgArr* argarr);
+// Destroy ArgArr structure but preserve -> buf.
+void argarr_destroypsv(ArgArr* argarr);
+void argarr_add(ArgArr* argarr, AST* arg);
+
+#include "../../build/grammars/grammar.tab.h"
+
+extern YYSTYPE yylval;
+
+// Accumulate an integer.
+int acc_int(int c);
+
+// Accumulate a floating-point number.
+double acc_float(int c);
+
+// Called by `yyparse()` (in bison-generated files.)
+int yylex();
+void yyerror(char const* s);
+
+#endif

src/include/main.h

@@ -1,6 +1,2 @@
-#ifndef MAIN_H
+// This file serves no purpose but because I've written my makefile this way it
-#define MAIN_H
+// has to exist for things to compile :P. TODO: Fix this.
-
-#include <stdio.h>
-
-#endif

src/include/parser.h

@@ -1,30 +0,0 @@
-#ifndef PARSER_H
-#define PARSER_H
-
-// Expression one of:
-// - Operation
-// - Number
-
-// Operation contains:
-// - Type
-// - Expression 1
-// - Expression 2
-
-typedef enum OpType {
-    OPTYPE_PLUS,
-    OPTYPE_MINUS
-} optype_t;
-
-typedef union Exp {
-    typedef struct Op {
-        optype_t type;
-        Exp* exp1;
-        Exp* exp2;
-    } op_t;
-
-    int n;
-} exp_t;
-
-
-
-#endif

src/include/stack.h

@@ -0,0 +1,23 @@
+#ifndef STACK_H
+#define STACK_H
+
+#include <stdlib.h>
+
+#define STACK_MAX 64
+
+typedef struct {
+    size_t i;               // Current index in the stack.
+    void* val[STACK_MAX];   // The stack itself.
+} Stack;
+
+Stack* stack_init();
+// Destroy a stack.
+// Note that `stack->i` must be `0`.
+void stack_destroy(Stack* stack);
+
+// Push a value to the stack.
+void stack_push(Stack* stack, void* val);
+// Pop a value from the stack.
+void* stack_pop(Stack* stack);
+
+#endif

src/include/util.c

@@ -1,12 +0,0 @@
-#ifndef UTIL_H
-#define UTIL_H
-
-// Utilies.
-
-#include <stdlib.h>
-#include <stdio.h>
-
-// Exit with an error. Returns int for ease of use, but should be treated as void.
-int die(char* msg);
-
-#endif

src/include/util.h

@@ -0,0 +1,85 @@
+#ifndef UTIL_H
+#define UTIL_H
+
+#ifdef DBG // Debug macros
+
+// Log a message.
+#define log_dbg(msg)                                                           \
+    printf("\033[37;1mdbg\033[0m:\033[37m%s\033[0m:\033[32m " msg "\033[0m\n", \
+           __func__);
+
+// Log a message with formatting.
+#define log_dbgf(msg, ...)                                                     \
+    printf("\033[37;1mdbg\033[0m:\033[37m%s\033[0m:\033[32m " msg "\033[0m\n", \
+           __func__, __VA_ARGS__);
+
+#else // ifdef DBG
+#define log_dbg(msg)
+#define log_dbgf(msg, ...)
+#endif // ifdef DBG else
+
+// Resent color code.
+#define COL_RESET "\e[0m"
+
+// Regular color codes.
+#define COL_BLA "\e[0;30m"
+#define COL_RED "\e[0;31m"
+#define COL_GRE "\e[0;32m"
+#define COL_YEL "\e[0;33m"
+#define COL_BLU "\e[0;34m"
+#define COL_MAG "\e[0;35m"
+#define COL_CYA "\e[0;36m"
+#define COL_WHI "\e[0;37m"
+
+// Bold color codes.
+#define COL_BBLA "\e[1;30m"
+#define COL_BRED "\e[1;31m"
+#define COL_BGRE "\e[1;32m"
+#define COL_BYEL "\e[1;33m"
+#define COL_BBLU "\e[1;34m"
+#define COL_BMAG "\e[1;35m"
+#define COL_BCYA "\e[1;36m"
+#define COL_BWHI "\e[1;37m"
+
+// Start in indent block.
+#define INDENT_BEGIN(ILVL)                                                     \
+    __attribute__((unused)) int INDENT_lvl = ILVL;                             \
+    Dstr* INDENT_spacing = dstr_init();                                        \
+    for (int INDENT_j = 0; INDENT_j < ILVL; INDENT_j++)                        \
+        dstr_appendch(INDENT_spacing, ' ');
+
+// Print & indent the title of a section.
+#define INDENT_TITLE(THING, WHERE)                                             \
+    printf("%s" COL_BCYA THING COL_RESET " @" COL_MAG " %p\n" COL_RESET, INDENT_spacing->buf, WHERE);
+
+// Print & indent a thing.
+#define INDENT_FIELD(FIELD, VAL, ...)                                          \
+    printf("%s " COL_BWHI FIELD ": " COL_RESET COL_WHI VAL COL_RESET "\n",     \
+           INDENT_spacing->buf, __VA_ARGS__);
+
+// Print & indent a thing with a newline before the val.
+#define INDENT_FIELD_NL(FIELD, VAL, ...)                                       \
+    printf("%s " COL_BWHI FIELD ":" COL_RESET "\n %s " COL_WHI VAL COL_RESET   \
+           "\n",                                                               \
+           INDENT_spacing->buf, INDENT_spacing->buf, __VA_ARGS__);
+
+// Print & indent a thing without any newline.
+#define INDENT_FIELD_EXT_NONL_START(FIELD)                                         \
+    printf("%s " COL_BWHI FIELD ":\n" COL_RESET COL_WHI, INDENT_spacing->buf);
+#define INDENT_FIELD_NONL_END printf( "\n" COL_RESET);
+
+// Print an array A of N things, by calling the function F.
+#define INDENT_FIELD_LIST(FIELD, A, N, F)                                      \
+    printf("%s " COL_BWHI FIELD ": [\n" COL_RESET, INDENT_spacing->buf);       \
+    for (int INDENT_i = 0; INDENT_i < N; INDENT_i++) {                         \
+        F(A[INDENT_i], INDENT_lvl + 2);                                        \
+    }                                                                          \
+    printf(COL_BWHI "%s ]\n" COL_RESET, INDENT_spacing->buf);
+
+// End an indent block.
+#define INDENT_END printf(COL_RESET); dstr_destroy(INDENT_spacing);
+
+// Allocate a pointer with a type.
+#define talloc(T, X) T* X = malloc(sizeof(T));
+
+#endif

src/lexer.c

@@ -0,0 +1,120 @@
+#include <complex.h>
+#include <ctype.h>
+#include <limits.h>
+#include <math.h>
+#include <stdio.h>
+
+#include "include/dstr.h"
+#include "include/lexer.h"
+#include "include/util.h"
+
+ArgArr* argarr_init() {
+    ArgArr* argarr = malloc(sizeof(ArgArr));
+
+    argarr->sz = ARLN * sizeof(AST*);
+    argarr->ln = 0;
+    argarr->buf = malloc(argarr->sz);
+
+    return argarr;
+}
+
+void argarr_destroy(ArgArr* argarr) {
+    free(argarr->buf);
+    free(argarr);
+}
+
+void argarr_destroypsv(ArgArr* argarr) { free(argarr); }
+
+void argarr_add(ArgArr* argarr, AST* arg) {
+    if ((argarr->ln + 1) * argarr->sz > argarr->sz) {
+        argarr->sz *= 2;
+        argarr->buf = realloc(argarr->buf, argarr->sz);
+        log_dbgf(
+            "ArgArr @ %p doubled from %ld to %ld", argarr, argarr->sz / 2,
+            argarr->sz
+        );
+    }
+
+    argarr->buf[argarr->ln++] = arg;
+}
+
+int acc_int(int c) {
+    int value = c - '0';
+    while (isdigit(*inp)) {
+        value = value * 10 + (*inp - '0'); // Accumulate value.
+        inp++;
+    }
+    return value;
+}
+
+double acc_float(int c) {
+    int dplaces = 0;
+    double value = (double)(c - '0');
+
+    // Grab everything prior to '.'.
+    while (isdigit(*inp)) {
+        value = value * 10 + (*inp - '0'); // Accumulate value.
+        inp++;
+    }
+
+    if (*inp == '.') {
+        inp++;
+
+        while (isdigit(*inp)) {
+            value = value * 10 + (*inp - '0'); // Accumulate value.
+            dplaces++;
+            inp++;
+        }
+        value = value / pow(10, dplaces);
+    }
+    return value;
+}
+
+char* acc_word(int c) {
+    Dstr* val = dstr_init();
+    do {
+        dstr_appendch(val, *(inp - 1));
+        inp++;
+    } while (isalpha(*inp));
+    dstr_appendch(val, *(inp - 1));
+
+    char* ret = val->buf;
+    dstr_destroypsv(val);
+    return ret;
+}
+
+int yylex() {
+    if (*inp == '\0') return YYEOF;
+
+    // Skip all whitespace.
+    while (*inp == ' ' || *inp == '\t') inp++;
+
+    // Assign & consume current character.
+    int c = *inp++;
+
+    // Check for NUM.
+    if (isdigit(c)) {
+        yylval.fval = acc_float(c); // Set the token value.
+        return NUM;
+    }
+
+    if (isalpha(c)) {
+        yylval.strval = acc_word(c);
+        return WORD;
+    }
+
+    switch (c) {
+        case '+':  return PLUS;
+        case '\n': return NL;
+        case '-':  return SUB;
+        case '*':  return MULT;
+        case '/':  return DIV;
+        case '(':  return LGROUP;
+        case ')':  return RGROUP;
+        case ',':  return SEP;
+        default:   fprintf(stderr, "Unexpected character: %c\n", c);
+    }
+
+    return 0;
+}
+void yyerror(char const* s) { fprintf(stderr, "Parse error: %s\n", s); }

src/main.c

@@ -1,6 +1,68 @@
 #include <stdio.h>
+#include <string.h>
+
+#include "include/ast.h"
+#include "include/dstr.h"
+#include "include/exec.h"
+#include "include/lexer.h"
+#include "include/util.h"
+
+#include "../build/grammars/grammar.tab.h"
+
+// Global Abstract Syntax Tree.
+extern AST* root;
+
+// Global input text.
+char* inp = NULL;
+
+extern int yyparse();
 
 int main(int argc, char** argv) {
-    printf("Hello, world!\n");
+
+    if (argc - 1 && strlen(argv[1]) > 0 && (inp = argv[1]) && !yyparse()) {
+        log_dbg("Parsed successfully!\n");
+        exec_print(exec_exp(root));
+        ast_destroy(root);
+        exit(0);
+    }
+
+    while (1) {
+        Dstr* ln = dstr_init();
+        char c;
+
+        printf("> ");
+        fflush(stdout);
+
+        // Accumulate line.
+        do {
+            c = getc(stdin);
+            switch (c) {
+                case EOF:  dstr_destroy(ln); goto lnskip;
+                case '\n': goto lnend;
+                default:   dstr_appendch(ln, c); log_dbgf("cchar: %c", c);
+            }
+        } while (1);
+
+    lnend:
+
+        log_dbgf("cline: %s", ln->buf);
+
+        if (ln->ln > 0) {
+            inp = ln->buf;
+            if (yyparse() == 0) {
+                log_dbg("Parsed successfully!\n");
+            } else printf("Parse error.\n");
+
+            exec_print(exec_exp(root));
+#ifdef DBG
+            ast_print(root);
+#endif
+            ast_destroy(root);
+        }
+
+        dstr_destroy(ln);
+    }
+lnskip:;
+
     return 0;
 }

src/stack.c

@@ -0,0 +1,40 @@
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "include/stack.h"
+#include "include/util.h"
+
+Stack* stack_init() {
+    talloc(Stack, stack);
+
+    memset(stack->val, 0, sizeof(void*) * STACK_MAX);
+    stack->i = 0;
+
+    return stack;
+}
+
+void stack_destroy(Stack* stack) {
+    // Can only free an empty stack.
+    assert(stack->i == 0);
+    free(stack);
+}
+
+void stack_push(Stack* stack, void* val) {
+    if (stack->i >= STACK_MAX) {
+        log_dbgf("Ran out of stack (max: %d)", STACK_MAX);
+        return;
+    }
+
+    stack->val[stack->i] = val;
+    stack->i++;
+}
+
+void* stack_pop(Stack* stack) {
+    if (stack->i <= 0) {
+        log_dbg("Can't pop empty stack.");
+        return (void*)-1;
+    }
+
+    return stack->val[--stack->i];
+}

src/util.c

@@ -0,0 +1 @@
+#include "include/util.h"

test/test_dstr.c

@@ -0,0 +1,79 @@
+#include "../src/include/dstr.h"
+#include "Unity/src/unity.h"
+#include <string.h>
+
+void setUp() {};
+void tearDown() {};
+
+void test_dstr_init() {
+    Dstr* dstr = dstr_init();
+    TEST_ASSERT_EQUAL(0, strlen(dstr->buf));
+    TEST_ASSERT_EQUAL(0, dstr->ln);
+    TEST_ASSERT_EQUAL(DSTR_INITSZ, dstr->bufsz);
+}
+
+void test_dstr_append() {
+    Dstr* dstr;
+
+    // Test simple appending.
+    dstr = dstr_init();
+    char* hello_world = "Hello, world!";
+    dstr_append(dstr, hello_world, strlen(hello_world));
+
+    TEST_ASSERT_EQUAL_STRING(hello_world, dstr->buf);
+    TEST_ASSERT_EQUAL(strlen(hello_world), dstr->ln);
+    TEST_ASSERT_EQUAL(DSTR_INITSZ, dstr->bufsz);
+
+    dstr_destroy(dstr);
+
+    // Test buffer doubling.
+    dstr = dstr_init();
+
+    char h[DSTR_INITSZ + 20];
+    memset(h, 'h', DSTR_INITSZ + 19);
+    h[DSTR_INITSZ + 19] = '\0';
+    dstr_append(dstr, h, strlen(h));
+
+    TEST_ASSERT_EQUAL_STRING(h, dstr->buf);
+    TEST_ASSERT_EQUAL(strlen(h), dstr->ln);
+    TEST_ASSERT_EQUAL(DSTR_INITSZ * 2, dstr->bufsz);
+}
+
+void test_dstr_appendch() {
+    Dstr* dstr;
+
+    // Test simple character appending.
+    dstr = dstr_init();
+    char c = 'c';
+    char* c_str = "c";
+    dstr_appendch(dstr, c);
+
+    TEST_ASSERT_EQUAL_STRING(c_str, dstr->buf);
+    TEST_ASSERT_EQUAL(strlen(c_str), dstr->ln);
+    TEST_ASSERT_EQUAL(DSTR_INITSZ, dstr->bufsz);
+
+    dstr_destroy(dstr);
+
+    // Test buffer doubling.
+    dstr = dstr_init();
+
+    // Test against this string.
+    char h[DSTR_INITSZ + 20];
+    memset(h, 'h', DSTR_INITSZ + 19);
+    h[DSTR_INITSZ + 19] = '\0';
+
+    for (int i = 0; i < DSTR_INITSZ + 19; i++) dstr_appendch(dstr, 'h');
+
+    TEST_ASSERT_EQUAL_STRING(h, dstr->buf);
+    TEST_ASSERT_EQUAL(strlen(h), dstr->ln);
+    TEST_ASSERT_EQUAL(DSTR_INITSZ * 2, dstr->bufsz);
+}
+
+// not needed when using generate_test_runner.rb
+int main(void) {
+    UNITY_BEGIN();
+    RUN_TEST(test_dstr_init);
+    RUN_TEST(test_dstr_append);
+    RUN_TEST(test_dstr_appendch);
+    return UNITY_END();
+}

test/validation/test.bats

@@ -0,0 +1,84 @@
+#!/usr/bin/env bats
+
+bin() { ./scl.out $1 | tail -n1; }
+
+@test "simple addition" {
+    run bin "1+1"
+    [ "$output" = "= 2.000000" ]
+
+    run bin "-1+1"
+    [ "$output" = "= 0.000000" ]
+
+    run bin "1+-1"
+    [ "$output" = "= 0.000000" ]
+
+    run bin "-1+-1"
+    [ "$output" = "= -2.000000" ]
+}
+
+@test "simple subtraction" {
+    run bin "1-1"
+    [ "$output" = "= 0.000000" ]
+
+    run bin "-1-1"
+    [ "$output" = "= -2.000000" ]
+
+    run bin "1--1"
+    [ "$output" = "= 2.000000" ]
+
+    run bin "-1--1"
+    [ "$output" = "= 0.000000" ]
+}
+
+@test "simple multiplication" {
+    run bin "1*2"
+    [ "$output" = "= 2.000000" ]
+
+    run bin "-1*2"
+    [ "$output" = "= -2.000000" ]
+
+    run bin "1*-1"
+    [ "$output" = "= -1.000000" ]
+
+    run bin "-1*-1"
+    [ "$output" = "= 1.000000" ]
+}
+
+@test "simple division" {
+    run bin "1/2"
+    [ "$output" = "= 0.500000" ]
+
+    run bin "-1/2"
+    [ "$output" = "= -0.500000" ]
+
+    run bin "1/-1"
+    [ "$output" = "= -1.000000" ]
+
+    run bin "-1/-1"
+    [ "$output" = "= 1.000000" ]
+}
+
+@test "order of operations" {
+    run bin "1+2*3"
+    [ "$output" = "= 7.000000" ]
+
+    run bin "2*3+1"
+    [ "$output" = "= 7.000000" ]
+
+    run bin "6/2-1"
+    [ "$output" = "= 2.000000" ]
+
+    run bin "1-6/2"
+    [ "$output" = "= -2.000000" ]
+}
+
+@test "order of operations with parenthesis" {
+    run bin "(1+2)*3"
+    [ "$output" = "= 9.000000" ]
+
+    run bin "-(1+2*3)"
+    [ "$output" = "= -7.000000" ]
+
+    run bin "-(-(1+2)*3)"
+    [ "$output" = "= 9.000000" ]
+}