From 5369c15e05aa5ada1bab159b62ca69ed0e170e2c Mon Sep 17 00:00:00 2001
From: "Johan B.W. de Vries" <info@jbwdevries.nl>
Date: Sun, 25 Jan 2026 13:02:08 +0100
Subject: [PATCH] Adds intinc as a buildint function

---
 0-lang0py/lang0py.py                          |  5 ++++
 1-lang0py/lang0py.lang0                       |  5 ++++
 2-lang0c/lang0c.lang0                         | 15 ++++++++++
 README.md                                     |  6 ++++
 .../test_intinc.exp.stdout                    |  5 ++++
 tests/test_stdlib_functions/test_intinc.lang0 | 28 +++++++++++++++++++
 6 files changed, 64 insertions(+)
 create mode 100644 tests/test_stdlib_functions/test_intinc.exp.stdout
 create mode 100644 tests/test_stdlib_functions/test_intinc.lang0

diff --git a/0-lang0py/lang0py.py b/0-lang0py/lang0py.py
index cea3e4c..97cb13b 100644
--- a/0-lang0py/lang0py.py
+++ b/0-lang0py/lang0py.py
@@ -478,6 +478,9 @@ def emitheader():
     emitln("def __strlen(a: str) -> str:")
     emitln("    return str(len(a))")
     emitln("")
+    emitln("def __intinc(a: str) -> str:")
+    emitln("    return str(int(a) + 1)")
+    emitln("")
     emitln("# ### END OF RUNTIME ### #")
     emitln("")
 
@@ -503,6 +506,8 @@ def main():
     mapsetkey("REGISTERID", "emit", "__emit")
     mapsetkey("FUNCREG", "eq", "1")
     mapsetkey("REGISTERID", "eq", "__eq")
+    mapsetkey("FUNCREG", "intinc", "1")
+    mapsetkey("REGISTERID", "intinc", "__intinc")
     mapsetkey("FUNCREG", "lt", "1")
     mapsetkey("REGISTERID", "lt", "__lt")
     mapsetkey("FUNCREG", "not", "1")
diff --git a/1-lang0py/lang0py.lang0 b/1-lang0py/lang0py.lang0
index abea5db..3435074 100644
--- a/1-lang0py/lang0py.lang0
+++ b/1-lang0py/lang0py.lang0
@@ -537,6 +537,9 @@ emitheader:
 	emitln "def __strlen(a: str) -> str:"
 	emitln "    return str(len(a))"
 	emitln ""
+	emitln "def __intinc(a: str) -> str:"
+	emitln "    return str(int(a) + 1)"
+	emitln ""
 	emitln "# ### END OF RUNTIME ### #"
 	emitln ""
 /
@@ -564,6 +567,8 @@ main:
 	mapsetkey "REGISTERID" "emit" "__emit"
 	mapsetkey "FUNCREG" "eq" "1"
 	mapsetkey "REGISTERID" "eq" "__eq"
+	mapsetkey "FUNCREG" "intinc" "1"
+	mapsetkey "REGISTERID" "intinc" "__intinc"
 	mapsetkey "FUNCREG" "lt" "1"
 	mapsetkey "REGISTERID" "lt" "__lt"
 	mapsetkey "FUNCREG" "not" "1"
diff --git a/2-lang0c/lang0c.lang0 b/2-lang0c/lang0c.lang0
index a297535..39082bb 100644
--- a/2-lang0c/lang0c.lang0
+++ b/2-lang0c/lang0c.lang0
@@ -810,6 +810,19 @@ emitheader:
 	emitln "    return buffer;"
 	emitln "}"
 	emitln ""
+	emitln "char * __intinc(char * inp)"
+	emitln "{"
+	emitln "    char * buffer = malloc(20);"
+	emitln "    char * endptr;"
+	emitln "    unsigned long long number = strtoull(inp, &endptr, 10);"
+	emit "    snprintf(buffer, 20, "
+	emit quote
+	emit "%llu"
+	emit quote
+	emitln ", number + 1);"
+	emitln "    return buffer;"
+	emitln "}"
+	emitln ""
 	emitln "// ### END OF RUNTIME ### //"
 	emitln ""
 	return
@@ -846,6 +859,8 @@ main:
 	mapsetkey "REGISTERID" "emit" "__emit"
 	mapsetkey "FUNCREG" "eq" "1"
 	mapsetkey "REGISTERID" "eq" "__eq"
+	mapsetkey "FUNCREG" "intinc" "1"
+	mapsetkey "REGISTERID" "intinc" "__intinc"
 	mapsetkey "FUNCREG" "lt" "1"
 	mapsetkey "REGISTERID" "lt" "__lt"
 	mapsetkey "FUNCREG" "not" "1"
diff --git a/README.md b/README.md
index 7d66304..5098cf5 100644
--- a/README.md
+++ b/README.md
@@ -155,6 +155,12 @@ Return true if the given strings are the same.
 
 Return true if a would sort before b.
 
+#### intinc
+
+Assumes `a` is a string containing solely a decimal integer.
+
+Returns a increased by one.
+
 #### mapclear mapname
 
 Maps are global and can be used from any function.
diff --git a/tests/test_stdlib_functions/test_intinc.exp.stdout b/tests/test_stdlib_functions/test_intinc.exp.stdout
new file mode 100644
index 0000000..1cf0f2d
--- /dev/null
+++ b/tests/test_stdlib_functions/test_intinc.exp.stdout
@@ -0,0 +1,5 @@
+0 + 1: 1
+5 + 1: 6
+9 + 1: 10
+15 + 1: 16
+99 + 1: 100
diff --git a/tests/test_stdlib_functions/test_intinc.lang0 b/tests/test_stdlib_functions/test_intinc.lang0
new file mode 100644
index 0000000..055de33
--- /dev/null
+++ b/tests/test_stdlib_functions/test_intinc.lang0
@@ -0,0 +1,28 @@
+main:
+	declare result
+
+	emit "0 + 1: "
+	calc result intinc "0"
+	emit result
+	emit eol
+
+	emit "5 + 1: "
+	calc result intinc "5"
+	emit result
+	emit eol
+
+	emit "9 + 1: "
+	calc result intinc "9"
+	emit result
+	emit eol
+
+	emit "15 + 1: "
+	calc result intinc "15"
+	emit result
+	emit eol
+
+	emit "99 + 1: "
+	calc result intinc "99"
+	emit result
+	emit eol
+/